コード例 #1
0
ファイル: ls.c プロジェクト: Rileybrains/NASA_Intern_SPICE
/* $Procedure    LS  ( Return L_s, planetocentric longitude of the sun ) */
doublereal ls_(integer *body, doublereal *et, char *corr, ftnlen corr_len)
{
    /* System generated locals */
    integer i__1, i__2;
    doublereal ret_val;

    /* Builtin functions */
    integer s_rnge(char *, integer, char *, integer);

    /* Local variables */
    doublereal tipm[9]	/* was [3][3] */;
    extern /* Subroutine */ int vequ_(doublereal *, doublereal *);
    integer i__;
    doublereal x[3], y[3], z__[3];
    extern /* Subroutine */ int chkin_(char *, ftnlen);
    doublereal uavel[3], npole[3], state[6], trans[9]	/* was [3][3] */;
    extern /* Subroutine */ int spkez_(integer *, doublereal *, char *, char *
	    , integer *, doublereal *, doublereal *, ftnlen, ftnlen), ucrss_(
	    doublereal *, doublereal *, doublereal *);
    doublereal lt;
    extern /* Subroutine */ int reclat_(doublereal *, doublereal *, 
	    doublereal *, doublereal *), tipbod_(char *, integer *, 
	    doublereal *, doublereal *, ftnlen);
    doublereal radius;
    extern /* Subroutine */ int chkout_(char *, ftnlen);
    extern logical return_(void);
    doublereal lat, pos[3];
    extern /* Subroutine */ int mxv_(doublereal *, doublereal *, doublereal *)
	    ;

/* $ Abstract */

/*     Compute L_s, the planetocentric longitude of the sun, as seen */
/*     from a specified body. */

/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */

/* $ Required_Reading */

/*     None. */

/* $ Keywords */

/*     GEOMETRY */

/* $ Declarations */
/* $ Brief_I/O */

/*     Variable  I/O  Description */
/*     --------  ---  -------------------------------------------------- */
/*     BODY       I   NAIF integer code of central body. */
/*     ET         I   Epoch in ephemeris seconds past J2000. */
/*     CORR       I   Aberration correction. */

/*     The function returns the value of L_s for the specified body */
/*     at the specified time. */

/* $ Detailed_Input */

/*     BODY        is the NAIF integer code of the central body, */
/*                 typically a planet. */

/*     ET          is the epoch in ephemeris seconds past J2000 at which */
/*                 the longitude of the sun (L_s) is to be computed. */

/*     CORR        indicates the aberration corrections to be applied */
/*                 when computing the longitude of the sun.  CORR */
/*                 may be any of the following. */

/*                    'NONE'     Apply no correction. */

/*                    'LT'       Correct the position of the sun, */
/*                               relative to the central body, for */
/*                               planetary (light time) aberration. */

/*                    'LT+S'     Correct the position of the sun, */
/*                               relative to the central body, for */
/*                               planetary and stellar aberrations. */

/* $ Detailed_Output */

/*     The function returns the value of L_s for the specified body */
/*     at the specified time.  This is the longitude of the Sun, */
/*     relative to the central body, in a right-handed frame whose */
/*     basis vectors are defined as follows: */

/*        - The positive Z direction is given by the instantaneous */
/*          angular velocity vector of the orbit of the body about */
/*          the sun. */

/*        - The positive X direction is that of the cross product of the */
/*          instantaneous north spin axis of the body with the positive */
/*          Z direction. */

/*        - The positive Y direction is Z x X. */

/*     Units are radians; the range is -pi to pi.  Longitudes are */
/*     positive east. */

/* $ Parameters */

/*     None. */

/* $ Exceptions */

/*     1) If no SPK (ephemeris) file has been loaded prior to calling */
/*        this routine, or if the SPK data has insufficient coverage, an */
/*        error will be diagnosed and signaled by a routine in the call */
/*        tree of this routine. */

/*     2) If a PCK file containing rotational elements for the central */
/*        body has not been loaded prior to calling this routine, an */
/*        error will be diagnosed and signaled by a routine called by a */
/*        routine in the call tree of this routine. */

/*     3) If the instantaneous angular velocity and spin axis of BODY */
/*        are parallel, the return value is unspecified. */

/* $ Files */

/*     1) An SPK file (or file) containing ephemeris data sufficient to */
/*        compute the geometric state of the central body relative to */
/*        the sun at ET must be loaded before this routine is called. If */
/*        light time correction is used, data must be available that */
/*        enable computation of the state the sun relative to the solar */
/*        system barycenter at the light-time corrected epoch.  If */
/*        stellar aberration correction is used, data must be available */
/*        that enable computation of the state the central body relative */
/*        to the solar system barycenter at ET. */

/*     2) A PCK file containing rotational elements for the central body */
/*        must be loaded before this routine is called. */

/* $ Particulars */

/*     The direction of the vernal equinox for the central body is */
/*     determined from the instantaneous equatorial and orbital planes */
/*     of the central body.  This equinox definition is specified in */
/*     reference [1].  The "instantaneous orbital plane" is interpreted */
/*     in this routine as the plane normal to the cross product of the */
/*     position and velocity of the central body relative to the sun. */
/*     A geometric state is used for this normal vector computation. */
/*     The "instantaneous equatorial plane" is that normal to the */
/*     central body's north pole at the requested epoch.  The pole */
/*     direction is determined from rotational elements loaded via */
/*     a PCK file. */

/*     The result returned by this routine will depend on the */
/*     ephemeris data and rotational elements used.  The result may */
/*     differ from that given in any particular version of the */
/*     Astronomical Almanac, due to differences in these input data, */
/*     and due to differences in precision of the computations. */

/* $ Examples */

/*     1) A simple program that computes L_s for Mars.  The geometric */
/*        state of the sun is used. */


/*            PROGRAM MARS_LS */
/*            IMPLICIT NONE */

/*            DOUBLE PRECISION      DPR */

/*            INTEGER               FILSIZ */
/*            PARAMETER           ( FILSIZ = 255 ) */

/*            CHARACTER*(FILSIZ)    PCK */
/*            CHARACTER*(FILSIZ)    SPK */
/*            CHARACTER*(FILSIZ)    LEAP */
/*            CHARACTER*(30)        UTC */
/*            CHARACTER*(15)        CORR */

/*            DOUBLE PRECISION      ET */
/*            DOUBLE PRECISION      LONG */
/*            DOUBLE PRECISION      LS */

/*            INTEGER               BODY */
/*            INTEGER               HANDLE */

/*            DATA  BODY   /  499      / */
/*            DATA  CORR   /  'NONE'   / */


/*            CALL PROMPT ( 'Enter name of leapseconds kernel > ', LEAP ) */
/*            CALL PROMPT ( 'Enter name of PCK file           > ', PCK  ) */
/*            CALL PROMPT ( 'Enter name of SPK file           > ', SPK  ) */

/*            CALL FURNSH ( LEAP ) */
/*            CALL FURNSH ( PCK  ) */
/*            CALL FURNSH ( SPK  ) */

/*            WRITE (*,*) ' ' */
/*            WRITE (*,*) 'Kernels have been loaded.' */
/*            WRITE (*,*) ' ' */

/*            DO WHILE ( .TRUE. ) */

/*               CALL PROMPT ( 'Enter UTC time > ', UTC ) */

/*               CALL UTC2ET ( UTC, ET ) */

/*      C */
/*      C        Convert longitude to degrees and move it into the range */
/*      C        [0, 360). */
/*      C */
/*               LONG = DPR() * LS ( BODY, ET, CORR ) */

/*               IF ( LONG .LT. 0.D0 ) THEN */
/*                  LONG = LONG + 360.D0 */
/*               END IF */

/*               WRITE (*,*) ' ' */
/*               WRITE (*,*) 'Mars L_s (deg.) = ',  LONG */
/*               WRITE (*,*) ' ' */

/*            END DO */

/*            END */

/* $ Restrictions */

/*     None. */

/* $ Literature_References */

/*     [1] "The Astronomical Almanac for the Year 2005." U.S. Government */
/*         Printing Office, Washington, D.C., 1984, page L9. */

/* $ Author_and_Institution */

/*     N.J. Bachman       (JPL) */

/* $ Version */

/* -    Chronos Version 1.1.2, 02-OCT-2006 (BVS) */

/*        Replaced LDPOOL and SPKELF with FURNSH in the Examples */
/*        section. */

/* -    Chronos Version 1.1.1, 07-JAN-2005 (NJB) */

/*        Description of reference frame in Detailed_Output header */
/*        section was corrected.  Miscellaneous other header updates */
/*        were made. */

/* -    Beta Version 1.1.0, 14-DEC-1996 (NJB) */

/* -& */

/*     SPICELIB functions */


/*     Local parameters */


/*     Local variables */


/*     Standard SPICE error handling. */

    if (return_()) {
	ret_val = 0.;
	return ret_val;
    } else {
	chkin_("LS", (ftnlen)2);
    }

/*     Look up the direction of the North pole of the central body. */

    tipbod_("J2000", body, et, tipm, (ftnlen)5);
    for (i__ = 1; i__ <= 3; ++i__) {
	npole[(i__1 = i__ - 1) < 3 && 0 <= i__1 ? i__1 : s_rnge("npole", i__1,
		 "ls_", (ftnlen)302)] = tipm[(i__2 = i__ * 3 - 1) < 9 && 0 <= 
		i__2 ? i__2 : s_rnge("tipm", i__2, "ls_", (ftnlen)302)];
    }

/*     Get the geometric state of the body relative to the sun. */

    spkez_(body, et, "J2000", "NONE", &c__10, state, &lt, (ftnlen)5, (ftnlen)
	    4);

/*     Get the unit direction vector parallel to the angular velocity */
/*     vector of the orbit.  This is just the unitized cross product of */
/*     position and velocity. */

    ucrss_(state, &state[3], uavel);

/*     We want to form a transformation matrix that maps vectors from */
/*     basis REF to the following frame: */

/*        Z  =  UAVEL */

/*        X  =  NPOLE x UAVEL */

/*        Y  =  Z x X */

/*     We'll find the position of the Sun relative to this frame.  In */
/*     our computations, we want our basis vectors to have unit length. */

    vequ_(uavel, z__);
    ucrss_(npole, z__, x);
    ucrss_(z__, x, y);
    for (i__ = 1; i__ <= 3; ++i__) {
	trans[(i__1 = i__ * 3 - 3) < 9 && 0 <= i__1 ? i__1 : s_rnge("trans", 
		i__1, "ls_", (ftnlen)335)] = x[(i__2 = i__ - 1) < 3 && 0 <= 
		i__2 ? i__2 : s_rnge("x", i__2, "ls_", (ftnlen)335)];
	trans[(i__1 = i__ * 3 - 2) < 9 && 0 <= i__1 ? i__1 : s_rnge("trans", 
		i__1, "ls_", (ftnlen)336)] = y[(i__2 = i__ - 1) < 3 && 0 <= 
		i__2 ? i__2 : s_rnge("y", i__2, "ls_", (ftnlen)336)];
	trans[(i__1 = i__ * 3 - 1) < 9 && 0 <= i__1 ? i__1 : s_rnge("trans", 
		i__1, "ls_", (ftnlen)337)] = z__[(i__2 = i__ - 1) < 3 && 0 <= 
		i__2 ? i__2 : s_rnge("z", i__2, "ls_", (ftnlen)337)];
    }

/*     Get the state of the sun in frame REF.  Since we may be using */
/*     aberration corrections, this is not necessarily the negative of */
/*     the state we've just found. */

    spkez_(&c__10, et, "J2000", corr, body, state, &lt, (ftnlen)5, corr_len);

/*     Now transform the position of the Sun into the "equator and */
/*     equinox" frame. */

    mxv_(trans, state, pos);

/*     Let RECLAT find the longitude LS for us. */

    reclat_(pos, &radius, &ret_val, &lat);
    chkout_("LS", (ftnlen)2);
    return ret_val;
} /* ls_ */
コード例 #2
0
ファイル: recgeo.c プロジェクト: Dbelsa/coft
/* $Procedure      RECGEO ( Rectangular to geodetic ) */
/* Subroutine */ int recgeo_(doublereal *rectan, doublereal *re, doublereal *
	f, doublereal *long__, doublereal *lat, doublereal *alt)
{
    doublereal base[3], a, b, c__;
    extern /* Subroutine */ int chkin_(char *, ftnlen), errdp_(char *, 
	    doublereal *, ftnlen), reclat_(doublereal *, doublereal *, 
	    doublereal *, doublereal *);
    doublereal radius, normal[3];
    extern /* Subroutine */ int nearpt_(doublereal *, doublereal *, 
	    doublereal *, doublereal *, doublereal *, doublereal *), sigerr_(
	    char *, ftnlen), chkout_(char *, ftnlen), setmsg_(char *, ftnlen),
	     surfnm_(doublereal *, doublereal *, doublereal *, doublereal *, 
	    doublereal *);
    extern logical return_(void);

/* $ Abstract */

/*     Convert from rectangular coordinates to geodetic coordinates. */

/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */

/* $ Required_Reading */

/*     None. */

/* $ Keywords */

/*      CONVERSION,  COORDINATES */

/* $ Declarations */
/* $ Brief_I/O */

/*     VARIABLE  I/O  DESCRIPTION */
/*     --------  ---  -------------------------------------------------- */
/*     RECTAN     I   Rectangular coordinates of a point. */
/*     RE         I   Equatorial radius of the reference spheroid. */
/*     F          I   Flattening coefficient. */
/*     LONG       O   Geodetic longitude of the point (radians). */
/*     LAT        O   Geodetic latitude  of the point (radians). */
/*     ALT        O   Altitude of the point above reference spheroid. */

/* $ Detailed_Input */

/*     RECTAN     The rectangular coordinates of a point. */

/*     RE         Equatorial radius of a reference spheroid.  This */
/*                spheroid is a volume of revolution:  its horizontal */
/*                cross sections are circular.  The shape of the */
/*                spheroid is defined by an equatorial radius RE and */
/*                a polar radius RP. */

/*     F          Flattening coefficient = (RE-RP) / RE,  where RP is */
/*                the polar radius of the spheroid. */

/* $ Detailed_Output */

/*     LONG       Geodetic longitude of the input point.  This is the */
/*                angle between the prime meridian and the meridian */
/*                containing RECTAN.  The direction of increasing */
/*                longitude is from the +X axis towards the +Y axis. */

/*                LONG is output in radians.  The range of LONG is */
/*                [-pi, pi]. */

/*     LAT        Geodetic latitude of the input point.  For a point P */
/*                on the reference spheroid, this is the angle between */
/*                the XY plane and the outward normal vector at P. */
/*                For a point P not on the reference spheroid, the */
/*                geodetic latitude is that of the closest point to P on */
/*                the spheroid. */

/*                LAT is output in radians.  The range of LAT is */
/*                [-pi/2, pi/2]. */


/*     ALT        Altitude of point above the reference spheroid. */

/*                The units associated with ALT are those associated */
/*                with the input RECTAN. */

/* $ Parameters */

/*     None. */

/* $ Exceptions */

/*     1) If the equatorial radius is non-positive, the error */
/*        SPICE(VALUEOUTOFRANGE) is signaled. */

/*     2) If the flattening coefficient is greater than or equal to */
/*        one, the error SPICE(VALUEOUTOFRANGE) is signaled. */

/*     3) For points inside the reference ellipsoid, the nearest */
/*        point on the ellipsoid to RECTAN may not be unique, so */
/*        latitude may not be well-defined. */

/* $ Files */

/*     None. */

/* $ Particulars */

/*     Given the body-fixed rectangular coordinates of a point, and the */
/*     constants describing the reference spheroid,  this routine */
/*     returns the geodetic coordinates of the point.  The body-fixed */
/*     rectangular frame is that having the x-axis pass through the */
/*     0 degree latitude 0 degree longitude point.  The y-axis passes */
/*     through the 0 degree latitude 90 degree longitude.  The z-axis */
/*     passes through the 90 degree latitude point.  For some bodies */
/*     this coordinate system may not be a right-handed coordinate */
/*     system. */

/* $ Examples */

/*     This routine can be used to convert body fixed rectangular */
/*     coordinates (such as the Satellite Tracking and Data Network */
/*     of 1973) to geodetic coordinates such as those used by the */
/*     United States Geological Survey topographic maps. */

/*     The code would look something like this */

/*     C */
/*     C     Shift the STDN-73 coordinates to line up with the center */
/*     C     of the Clark66 reference system. */
/*     C */
/*           CALL VSUB ( STDNX, OFFSET, X ) */

/*     C */
/*     C     Using the equatorial radius of the Clark66 spheroid */
/*     C     (CLARKR = 6378.2064 km) and the Clark 66 flattening */
/*     C     factor (CLARKF = 1.0D0 / 294.9787D0 ) convert to */
/*     C     geodetic coordinates of the North American Datum of 1927. */
/*     C */
/*           CALL RECGEO ( X, CLARKR, CLARKF, LONG, LAT, ALT ) */



/*     Below are two tables. */

/*     Listed in the first table (under X(1), X(2) and X(3)) are a */
/*     number of points whose rectangular coordinates are */
/*     taken from the set {-1, 0, 1}. */

/*     The results of the code fragment */

/*          CALL RECGEO ( X, CLARKR, CLARKF, LONG, LAT, ALT ) */

/*          Use the SPICELIB routine CONVRT to convert the angular */
/*          quantities to degrees */

/*          CALL CONVRT ( LAT,  'RADIANS', 'DEGREES', LAT  ) */
/*          CALL CONVRT ( LONG, 'RADIANS', 'DEGREES', LONG ) */

/*     are listed to 4 decimal places in the second parallel table under */
/*     LONG (longitude), LAT (latitude), and ALT (altitude). */


/*       X(1)       X(2)     X(3)         LONG      LAT        ALT */
/*       --------------------------       ---------------------------- */
/*       0.0000     0.0000   0.0000       0.0000    90.0000   -6356.5838 */
/*       1.0000     0.0000   0.0000       0.0000     0.0000   -6377.2063 */
/*       0.0000     1.0000   0.0000      90.0000     0.0000   -6377.2063 */
/*       0.0000     0.0000   1.0000       0.0000    90.0000   -6355.5838 */
/*      -1.0000     0.0000   0.0000     180.0000     0.0000   -6377.2063 */
/*       0.0000    -1.0000   0.0000     -90.0000     0.0000   -6377.2063 */
/*       0.0000     0.0000  -1.0000       0.0000   -90.0000   -6355.5838 */
/*       1.0000     1.0000   0.0000      45.0000     0.0000   -6376.7921 */
/*       1.0000     0.0000   1.0000       0.0000    88.7070   -6355.5725 */
/*       0.0000     1.0000   1.0000      90.0000    88.7070   -6355.5725 */
/*       1.0000     1.0000   1.0000      45.0000    88.1713   -6355.5612 */

/* $ Restrictions */

/*     None. */

/* $ Literature_References */

/*     See FUNDAMENTALS OF ASTRODYNAMICS, Bate, Mueller, White */
/*     published by Dover for a description of geodetic coordinates. */

/* $ Author_and_Institution */

/*     C.H. Acton      (JPL) */
/*     N.J. Bachman    (JPL) */
/*     H.A. Neilan     (JPL) */
/*     W.L. Taber      (JPL) */

/* $ Version */

/* -    SPICELIB Version 1.0.3, 02-JUL-2007 (NJB) */

/*        In Examples section of header, description of right-hand */
/*        table was updated to use correct names of columns. Term */
/*        "bodyfixed" is now hyphenated. */

/* -    SPICELIB Version 1.0.2, 30-JUL-2003 (NJB) (CHA) */

/*        Various header changes were made to improve clarity.  Some */
/*        minor header corrections were made. */

/* -    SPICELIB Version 1.0.1, 10-MAR-1992 (WLT) */

/*        Comment section for permuted index source lines was added */
/*        following the header. */

/* -    SPICELIB Version 1.0.0, 31-JAN-1990 (WLT) */

/* -& */
/* $ Index_Entries */

/*     rectangular to geodetic */

/* -& */
/* $ Revisions */

/* -    Beta Version 3.0.1, 9-JUN-1989 (HAN) */

/*        Error handling was added to detect and equatorial radius */
/*        whose value is less than or equal to zero. */

/* -    Beta Version 2.0.0, 21-DEC-1988 (HAN) */

/*        Error handling to detect invalid flattening coefficients */
/*        was added. Because the flattening coefficient is used to */
/*        compute the length of an axis, it must be checked so that */
/*        the length is greater than zero. */

/* -& */

/*     SPICELIB functions */


/*     Local variables */


/*     Standard SPICE error handling. */

    if (return_()) {
	return 0;
    } else {
	chkin_("RECGEO", (ftnlen)6);
    }

/*     The equatorial radius must be positive. If not, signal an error */
/*     and check out. */

    if (*re <= 0.) {
	setmsg_("Equatorial radius was *.", (ftnlen)24);
	errdp_("*", re, (ftnlen)1);
	sigerr_("SPICE(VALUEOUTOFRANGE)", (ftnlen)22);
	chkout_("RECGEO", (ftnlen)6);
	return 0;
    }

/*     If the flattening coefficient is greater than one, the length */
/*     of the 'C' axis computed below is negative. If it's equal to one, */
/*     the length of the axis is zero. Either case is a problem, so */
/*     signal an error and check out. */

    if (*f >= 1.) {
	setmsg_("Flattening coefficient was *.", (ftnlen)29);
	errdp_("*", f, (ftnlen)1);
	sigerr_("SPICE(VALUEOUTOFRANGE)", (ftnlen)22);
	chkout_("RECGEO", (ftnlen)6);
	return 0;
    }

/*     Determine the lengths of the axes of the reference ellipsoid. */

    a = *re;
    b = *re;
    c__ = *re - *f * *re;

/*     Find the point on the reference spheroid closes to the input point */

    nearpt_(rectan, &a, &b, &c__, base, alt);

/*     From this closest point determine the surface normal */

    surfnm_(&a, &b, &c__, base, normal);

/*     Using the surface normal, determine the latitude and longitude */
/*     of the input point. */

    reclat_(normal, &radius, long__, lat);
    chkout_("RECGEO", (ftnlen)6);
    return 0;
} /* recgeo_ */
コード例 #3
0
ファイル: xfmsta.c プロジェクト: Dbelsa/coft
/* $Procedure      XFMSTA ( Transform state between coordinate systems) */
/* Subroutine */ int xfmsta_(doublereal *istate, char *icosys, char *ocosys, 
	char *body, doublereal *ostate, ftnlen icosys_len, ftnlen ocosys_len, 
	ftnlen body_len)
{
    /* Initialized data */

    static char cosys[40*6] = "RECTANGULAR                             " 
	    "CYLINDRICAL                             " "LATITUDINAL         "
	    "                    " "SPHERICAL                               " 
	    "GEODETIC                                " "PLANETOGRAPHIC      "
	    "                    ";
    static logical first = TRUE_;

    /* System generated locals */
    integer i__1, i__2;
    doublereal d__1, d__2;

    /* Builtin functions */
    double sqrt(doublereal);
    integer s_rnge(char *, integer, char *, integer);

    /* Local variables */
    extern /* Subroutine */ int zzbods2c_(integer *, char *, integer *, 
	    logical *, char *, integer *, logical *, ftnlen, ftnlen);
    doublereal ivel[3], ipos[3];
    extern /* Subroutine */ int vequ_(doublereal *, doublereal *);
    integer isys, osys;
    doublereal f;
    extern /* Subroutine */ int zzctruin_(integer *);
    integer i__, j;
    doublereal radii[3];
    extern /* Subroutine */ int chkin_(char *, ftnlen), errch_(char *, char *,
	     ftnlen, ftnlen), vpack_(doublereal *, doublereal *, doublereal *,
	     doublereal *);
    extern doublereal dpmax_(void);
    logical found;
    extern /* Subroutine */ int errdp_(char *, doublereal *, ftnlen), vequg_(
	    doublereal *, integer *, doublereal *);
    doublereal sqtmp;
    char isysu[40], osysu[40];
    static logical svfnd1;
    static integer svctr1[2];
    extern logical failed_(void);
    doublereal jacobi[9]	/* was [3][3] */;
    extern /* Subroutine */ int bodvcd_(integer *, char *, integer *, integer 
	    *, doublereal *, ftnlen), georec_(doublereal *, doublereal *, 
	    doublereal *, doublereal *, doublereal *, doublereal *), drdgeo_(
	    doublereal *, doublereal *, doublereal *, doublereal *, 
	    doublereal *, doublereal *), recgeo_(doublereal *, doublereal *, 
	    doublereal *, doublereal *, doublereal *, doublereal *), dgeodr_(
	    doublereal *, doublereal *, doublereal *, doublereal *, 
	    doublereal *, doublereal *);
    integer bodyid;
    extern integer isrchc_(char *, integer *, char *, ftnlen, ftnlen);
    static integer svbdid;
    extern /* Subroutine */ int latrec_(doublereal *, doublereal *, 
	    doublereal *, doublereal *), drdlat_(doublereal *, doublereal *, 
	    doublereal *, doublereal *), cylrec_(doublereal *, doublereal *, 
	    doublereal *, doublereal *), drdcyl_(doublereal *, doublereal *, 
	    doublereal *, doublereal *);
    doublereal toobig;
    extern /* Subroutine */ int sphrec_(doublereal *, doublereal *, 
	    doublereal *, doublereal *), drdsph_(doublereal *, doublereal *, 
	    doublereal *, doublereal *), pgrrec_(char *, doublereal *, 
	    doublereal *, doublereal *, doublereal *, doublereal *, 
	    doublereal *, ftnlen), drdpgr_(char *, doublereal *, doublereal *,
	     doublereal *, doublereal *, doublereal *, doublereal *, ftnlen), 
	    reccyl_(doublereal *, doublereal *, doublereal *, doublereal *), 
	    reclat_(doublereal *, doublereal *, doublereal *, doublereal *), 
	    sigerr_(char *, ftnlen), recsph_(doublereal *, doublereal *, 
	    doublereal *, doublereal *), chkout_(char *, ftnlen), recpgr_(
	    char *, doublereal *, doublereal *, doublereal *, doublereal *, 
	    doublereal *, doublereal *, ftnlen), dcyldr_(doublereal *, 
	    doublereal *, doublereal *, doublereal *), dlatdr_(doublereal *, 
	    doublereal *, doublereal *, doublereal *), ljucrs_(integer *, 
	    char *, char *, ftnlen, ftnlen), setmsg_(char *, ftnlen), dsphdr_(
	    doublereal *, doublereal *, doublereal *, doublereal *);
    static char svbody[36];
    extern /* Subroutine */ int dpgrdr_(char *, doublereal *, doublereal *, 
	    doublereal *, doublereal *, doublereal *, doublereal *, ftnlen);
    extern logical return_(void);
    integer dim;
    extern /* Subroutine */ int mxv_(doublereal *, doublereal *, doublereal *)
	    ;

/* $ Abstract */

/*     Transform a state between coordinate systems. */

/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */

/* $ Required_Reading */

/*     None. */

/* $ Keywords */

/*     CONVERSION */
/*     COORDINATE */
/*     EPHEMERIS */
/*     STATE */

/* $ Declarations */
/* $ Abstract */

/*     This include file defines the dimension of the counter */
/*     array used by various SPICE subsystems to uniquely identify */
/*     changes in their states. */

/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */

/* $ Parameters */

/*     CTRSIZ      is the dimension of the counter array used by */
/*                 various SPICE subsystems to uniquely identify */
/*                 changes in their states. */

/* $ Author_and_Institution */

/*     B.V. Semenov    (JPL) */

/* $ Literature_References */

/*     None. */

/* $ Version */

/* -    SPICELIB Version 1.0.0, 29-JUL-2013 (BVS) */

/* -& */

/*     End of include file. */

/* $ Brief_I/O */

/*     VARIABLE  I/O  DESCRIPTION */
/*     --------  ---  ------------------------------------------------- */
/*     ISTATE     I   Input state. */
/*     ICOSYS     I   Current (input) coordinate system. */
/*     OCOSYS     I   Desired (output) coordinate system. */
/*     BODY       I   Name or NAIF ID of body with which */
/*                    coordinates are associated (if applicable). */
/*     OSTATE     O   Converted output state. */

/* $ Detailed_Input */

/*     ISTATE     is a state vector in the input (ICOSYS) coordinate */
/*                system representing position and velocity. */

/*                All angular measurements must be in radians. */

/*                Note: body radii values taken from the kernel */
/*                pool are used when converting to or from geodetic or */
/*                planetographic coordinates. It is the user's */
/*                responsibility to verify the distance inputs are in */
/*                the same units as the radii in the kernel pool, */
/*                typically kilometers. */

/*     ICOSYS     is the name of the coordinate system that the input */
/*                state vector (ISTATE) is currently in. */

/*                ICOSYS may be any of the following: */

/*                    'RECTANGULAR' */
/*                    'CYLINDRICAL' */
/*                    'LATITUDINAL' */
/*                    'SPHERICAL' */
/*                    'GEODETIC' */
/*                    'PLANETOGRAPHIC' */

/*                Leading spaces, trailing spaces, and letter case */
/*                are ignored. For example, ' cyLindRical  ' would be */
/*                accepted. */

/*     OCOSYS     is the name of the coordinate system that the state */
/*                should be converted to. */

/*                Please see the description of ICOSYS for details. */

/*     BODY       is the name or NAIF ID of the body associated with the */
/*                planetographic or geodetic coordinate system. */

/*                If neither of the coordinate system choices are */
/*                geodetic or planetographic, BODY may be an empty */
/*                string (' '). */

/*                Examples of accepted body names or IDs are: */
/*                         'Earth' */
/*                         '399' */

/*                Leading spaces, trailing spaces, and letter case are */
/*                ignored. */

/* $ Detailed_Output */

/*     OSTATE     is the state vector that has been converted to the */
/*                output coordinate system (OCOSYS). */

/* $ Parameters */

/*     None. */

/* $ Exceptions */

/*     1)  If either the input or output coordinate system is not */
/*         recognized, the error SPICE(COORDSYSNOTREC) is signaled. */

/*     2)  If the input body name cannot be converted to a NAIF ID */
/*         (applies to geodetic and planetographic coordinate */
/*         systems), the error 'SPICE(IDCODENOTFOUND)' is signaled. */

/*     3)  If the input state ISTATE is not valid, meaning the position */
/*         but not the velocity is along the z-axis, the error */
/*         'SPICE(INVALIDSTATE)' is signaled. */

/*         Note: If both the input position and velocity are along */
/*         the z-axis and the output coordinate system is not */
/*         rectangular, the velocity can still be calculated even */
/*         though the Jacobian is undefined. This case will not */
/*         signal an error. An example of the input position and */
/*         velocity along the z-axis is below. */

/*                       Term    Value */
/*                       -----   ------ */
/*                         x       0 */
/*                         y       0 */
/*                         z       z */
/*                       dx/dt     0 */
/*                       dy/dt     0 */
/*                       dz/dt   dz_dt */

/*     4)  If either the input or output coordinate system is */
/*         geodetic or planetographic and at least one of the body's */
/*         radii is less than or equal to zero, the error */
/*         SPICE(INVALIDRADIUS) will be signaled. */

/*     5)  If either the input or output coordinate system is */
/*         geodetic or planetographic and the difference of the */
/*         equatorial and polar radii divided by the equatorial radius */
/*         would produce numeric overflow, the error */
/*         'SPICE(INVALIDRADIUS)' will be signaled. */

/*     6)  If the product of the Jacobian and velocity components */
/*         may lead to numeric overflow, the error */
/*         'SPICE(NUMERICOVERFLOW)' is signaled. */

/* $ Files */

/*     SPK, PCK, CK, and FK kernels may be required. */

/*     If the input or output coordinate systems are either geodetic or */
/*     planetographic, a PCK providing the radii of the body */
/*     name BODY must be loaded via FURNSH. */

/*     Kernel data are normally loaded once per program run, NOT every */
/*     time this routine is called. */

/* $ Particulars */

/*     Input Order */
/*     ------------------------------------------- */

/*     The input and output states will be structured by the */
/*     following descriptions. */

/*     For rectangular coordinates, the state vector is the following */
/*     in which X, Y, and Z are the rectangular position components and */
/*     DX, DY, and DZ are the time derivatives of each position */
/*     component. */

/*             ISTATE = ( X, Y, Z, DX, DY, DZ ) */

/*     For cylindrical coordinates, the state vector is the following */
/*     in which R is the radius, LONG is the longitudes, Z is the */
/*     height, and DR, DLONG, and DZ are the time derivatives of each */
/*     position component. */

/*             ISTATE = ( R, LONG, Z, DR, DLONG, DZ ) */

/*     For latitudinal coordinates, the state vector is the following */
/*     in which R is the radius, LONG is the longitude, LAT is the */
/*     latitude, and DR, DLONG, and DLAT are the time derivatives of */
/*     each position component. */

/*             ISTATE = ( R, LONG, LAT, DR, DLONG, DLAT ) */

/*     For spherical coordinates, the state vector is the following in */
/*     which R is the radius, COLAT is the colatitude, LONG is the */
/*     longitude, and DR, DCOLAT, and DLONG are the time derivatives of */
/*     each position component. */

/*             ISTATE = ( R, COLAT, LONG, DR, DCOLAT, DLONG ) */

/*     For geodetic coordinates, the state vector is the following in */
/*     which LONG is the longitude, LAT is the latitude, ALT is the */
/*     altitude, and DLONG, DLAT, and DALT are the time derivatives of */
/*     each position component. */

/*             ISTATE = ( LONG, LAT, ALT, DLONG, DLAT, DALT ) */

/*     For planetographic coordinates, the state vector is the */
/*     following in which LONG is the longitude, LAT is the latitude, */
/*     ALT is the altitude, and DLONG, DLAT, and DALT are the time */
/*     derivatives of each position component. */

/*             ISTATE = ( LONG, LAT, ALT, DLONG, DLAT, DALT ) */


/*     Input Boundaries */
/*     ------------------------------------------- */

/*     There are intervals the input angles must fall within if */
/*     the input coordinate system is not rectangular. These */
/*     intervals are provided below. */

/*        Input variable    Input meaning   Input interval [rad] */
/*        --------------    -------------   ------------------------ */
/*            LONG           Longitude        0     <= LONG  <  2*pi */
/*            LAT            Latitude        -pi/2  <= LAT   <= pi/2 */
/*            COLAT          Colatitude       0     <= COLAT <= pi */


/* $ Examples */

/*     The numerical results shown for these examples may differ across */
/*     platforms. The results depend on the SPICE kernels used as */
/*     input, the compiler and supporting libraries, and the machine */
/*     specific arithmetic implementation. */

/*     1) Find the apparent state of Phoebe as seen by CASSINI in the */
/*        J2000 frame at 2004 Jun 11 19:32:00. Transform the state */
/*        from rectangular to latitudinal coordinates. For verification, */
/*        transform the state back from latitudinal to rectangular */
/*        coordinates. */

/*        Use the meta-kernel shown below to load the required SPICE */
/*        kernels. */

/*           KPL/MK */

/*           File name: xfmsta_ex1.tm */

/*           This meta-kernel is intended to support operation of SPICE */
/*           example programs. The kernels shown here should not be */
/*           assumed to contain adequate or correct versions of data */
/*           required by SPICE-based user applications. */

/*           In order for an application to use this meta-kernel, the */
/*           kernels referenced here must be present in the user's */
/*           current working directory. */

/*           The names and contents of the kernels referenced */
/*           by this meta-kernel are as follows: */

/*                  File name                     Contents */
/*                  ---------                     -------- */
/*                  cpck05Mar2004.tpc             Planet orientation and */
/*                                                radii */
/*                  naif0009.tls                  Leapseconds */
/*                  020514_SE_SAT105.bsp          Satellite ephemeris for */
/*                                                Saturn */
/*                  030201AP_SK_SM546_T45.bsp     CASSINI ephemeris */
/*                  981005_PLTEPH-DE405S.bsp      Planetary ephemeris */


/*           \begindata */

/*           KERNELS_TO_LOAD = ( 'naif0009.tls'  , */
/*                               '020514_SE_SAT105.bsp'  , */
/*                               '030201AP_SK_SM546_T45.bsp'  , */
/*                               '981005_PLTEPH-DE405S.bsp', */
/*                               'cpck05Mar2004.tpc'   ) */

/*           End of meta-kernel */

/*        Example code begins here. */

/*           PROGRAM  EX1_XFMSTA */
/*           IMPLICIT NONE */
/*     C */
/*     C     Local parameters */
/*     C */
/*     C     METAKR is the meta-kernel's filename. */
/*     C */
/*           CHARACTER*(*)         METAKR */
/*           PARAMETER           ( METAKR = 'xfmsta_ex1.tm' ) */

/*           CHARACTER*(*)         FORM */
/*           PARAMETER           ( FORM = '(F16.6, F16.6, F16.6)' ) */

/*     C */
/*     C     Local variables */
/*     C */
/*     C     STAREC is the state of Phoebe with respect to CASSINI in */
/*     C     rectangular coordinates. STALAT is the state rotated into */
/*     C     latitudinal coordinates. STREC2 is the state transformed */
/*     C     back into rectangular coordinates from latitudinal. */
/*     C */
/*           DOUBLE PRECISION      STAREC (6) */
/*           DOUBLE PRECISION      STALAT (6) */
/*           DOUBLE PRECISION      STREC2 (6) */

/*     C */
/*     C     ET is the ephemeris time (TDB) corresponding to the */
/*     C     observation. */
/*     C */
/*           DOUBLE PRECISION      ET */
/*           DOUBLE PRECISION      LT */

/*           INTEGER               I */

/*     C */
/*     C     The required kernels must be loaded. */
/*     C */
/*           CALL FURNSH ( METAKR ) */

/*     C */
/*     C     Calculate the state at 2004 Jun 11 19:32:00 UTC. */
/*     C */
/*           CALL STR2ET ( '2004-JUN-11-19:32:00', ET ) */

/*     C */
/*     C     Calculate the apparent state of Phoebe as seen by */
/*     C     CASSINI in the J2000 frame. */
/*     C */
/*           CALL SPKEZR ( 'PHOEBE',  ET, 'IAU_PHOEBE', 'LT+S', */
/*          .              'CASSINI', STAREC, LT ) */

/*     C */
/*     C     Transform the state from rectangular to latitudinal. */
/*     C     Notice that since neither the input nor output */
/*     C     coordinate frames are 'geodetic' or 'planetographic', */
/*     C     the input for the body name is a blank string. */
/*     C */
/*           CALL XFMSTA ( STAREC, 'RECTANGULAR', 'LATITUDINAL', ' ', */
/*          .              STALAT ) */

/*     C */
/*     C     Transform the state back to rectangular from latitudinal */
/*     C     for verification. This result should be very similar to */
/*     C     STAREC. */
/*     C */
/*           CALL XFMSTA ( STALAT, 'LATITUDINAL', 'RECTANGULAR',' ', */
/*          .              STREC2 ) */

/*     C */
/*     C     Report the results. */
/*     C */
/*           WRITE (*,*)    ' ' */
/*           WRITE (*,*)    'Phoebe as seen by CASSINI - rectangular' */
/*           WRITE (*,*)    '  Position [km]:' */
/*           WRITE (*,FORM) (STAREC(I), I = 1, 3) */
/*           WRITE (*,*)    '  Velocity [km/s]:' */
/*           WRITE (*,FORM) (STAREC(I), I = 4, 6) */
/*           WRITE (*,*)    ' ' */
/*           WRITE (*,*)    'Phoebe as seen by CASSINI - latitudinal' */
/*           WRITE (*,*)    '  Position [km, rad, rad]:' */
/*           WRITE (*,FORM) (STALAT(I), I = 1, 3) */
/*           WRITE (*,*)    '  Velocity [km/s, rad/s, rad/s]:' */
/*           WRITE (*,FORM) (STALAT(I), I = 4, 6) */
/*           WRITE (*,*)    ' ' */
/*           WRITE (*,*)    'Verification: ' */
/*           WRITE (*,*)    'Phoebe as seen by CASSINI - rectangular' */
/*           WRITE (*,*)    '  Position [km]:' */
/*           WRITE (*,FORM) (STREC2(I), I = 1, 3) */
/*           WRITE (*,*)    '  Velocity [km/s]:' */
/*           WRITE (*,FORM) (STREC2(I), I = 4, 6) */

/*           END */

/*        When this program was executed using gfortran on a PC Linux */
/*        64 bit environment, the output was: */

/*             Phoebe as seen by CASSINI - rectangular */
/*               Position [km]: */
/*                -1982.639762     -934.530471     -166.562595 */
/*               Velocity [km/s]: */
/*                    3.970832       -3.812496       -2.371663 */

/*             Phoebe as seen by CASSINI - latitudinal */
/*               Position [km, rad, rad]: */
/*                 2198.169858       -2.701121       -0.075846 */
/*               Velocity [km/s, rad/s, rad/s]: */
/*                   -1.780939        0.002346       -0.001144 */

/*             Verification: */
/*             Phoebe as seen by CASSINI - rectangular */
/*               Position [km]: */
/*                -1982.639762     -934.530471     -166.562595 */
/*               Velocity [km/s]: */
/*                    3.970832       -3.812496       -2.371663 */

/*     2) Transform a given state from cylindrical to planetographic */
/*        coordinates with respect to Earth. */

/*        Use the meta-kernel shown below to load the required SPICE */
/*        kernels. */

/*           KPL/MK */

/*           File name: xfmsta_ex2.tm */

/*           This meta-kernel is intended to support operation of SPICE */
/*           example programs. The kernels shown here should not be */
/*           assumed to contain adequate or correct versions of data */
/*           required by SPICE-based user applications. */

/*           In order for an application to use this meta-kernel, the */
/*           kernels referenced here must be present in the user's */
/*           current working directory. */

/*           The names and contents of the kernels referenced */
/*           by this meta-kernel are as follows: */

/*              File name                     Contents */
/*              ---------                     -------- */
/*              cpck05Mar2004.tpc             Planet orientation and */
/*                                            radii */

/*           \begindata */

/*              KERNELS_TO_LOAD = ( 'cpck05Mar2004.tpc' ) */

/*           \begintext */

/*           End of meta-kernel */


/*        Example code begins here. */

/*           PROGRAM  EX2_XFMSTA */
/*           IMPLICIT NONE */

/*     C */
/*     C     Local parameters */
/*     C */
/*     C     METAKR is the meta-kernel's filename. */
/*     C */
/*           CHARACTER*(*)         METAKR */
/*           PARAMETER           ( METAKR = 'xfmsta_ex2.tm' ) */

/*           CHARACTER*(*)         FORM */
/*           PARAMETER           ( FORM = '(F16.6, F16.6, F16.6)' ) */

/*     C */
/*     C     Local variables */
/*     C */
/*     C     STACYL is the state in cylindrical coordinates. */
/*     C */
/*           DOUBLE PRECISION      STACYL (6) */
/*     C */
/*     C     STAPLN is the state transformed into planetographic */
/*     C     coordinates. */
/*     C */
/*           DOUBLE PRECISION      STAPLN (6) */
/*     C */
/*     C     STCYL2 is the state transformed back into */
/*     C     cylindrical coordinates from planetographic. */
/*     C */
/*           DOUBLE PRECISION      STCYL2 (6) */

/*           INTEGER               I */

/*           DATA STACYL / 1.0D0, 0.5D0, 0.5D0, 0.2D0, 0.1D0, -0.2D0 / */
/*     C */
/*     C     The required kernels must be loaded. */
/*     C */
/*           CALL FURNSH ( METAKR ) */

/*     C */
/*     C     Transform the state from cylindrical to planetographic. */
/*     C     Note that since one of the coordinate systems is */
/*     C     planetographic, the body name must be input. */
/*     C */
/*           CALL XFMSTA ( STACYL, 'CYLINDRICAL', 'PLANETOGRAPHIC', */
/*          .              'EARTH', STAPLN ) */

/*     C */
/*     C     Transform the state back to cylindrical from */
/*     C     planetographic for verification. The result should be very */
/*     C     close to STACYL. */
/*     C */
/*           CALL XFMSTA ( STAPLN, 'PLANETOGRAPHIC', 'CYLINDRICAL', */
/*          .              'EARTH', STCYL2 ) */

/*     C */
/*     C     Report the results. */
/*     C */
/*           WRITE (*,*)    'Cylindrical state' */
/*           WRITE (*,*)    '  Position [km, rad, km]:' */
/*           WRITE (*,FORM) (STACYL(I), I = 1, 3) */
/*           WRITE (*,*)    '  Velocity [km/s, rad/s, km/s]:' */
/*           WRITE (*,FORM) (STACYL(I), I = 4, 6) */
/*           WRITE (*,*)    ' ' */
/*           WRITE (*,*) 'Planetographic state' */
/*           WRITE (*,*)    '  Position [rad, rad, km]:' */
/*           WRITE (*,FORM) (STAPLN(I), I = 1, 3) */
/*           WRITE (*,*)    '  Velocity [rad/s, rad/s, km/s]:' */
/*           WRITE (*,FORM) (STAPLN(I), I = 4, 6) */
/*           WRITE (*,*)    ' ' */
/*           WRITE (*,*)    'Verification:  Cylindrical state' */
/*           WRITE (*,*)    '  Position [km, rad, km]:' */
/*           WRITE (*,FORM) (STCYL2(I), I = 1, 3) */
/*           WRITE (*,*)    '  Velocity [km/s, rad/s, km/s]:' */
/*           WRITE (*,FORM) (STCYL2(I), I = 4, 6) */

/*           END */

/*        When this program was executed using gfortran on a PC Linux */
/*        64 bit environment, the output was: */

/*             Cylindrical state */
/*               Position [km, rad, km]: */
/*                    1.000000        0.500000        0.500000 */
/*               Velocity [km/s, rad/s, km/s]: */
/*                    0.200000        0.100000       -0.200000 */

/*             Planetographic state */
/*               Position [rad, rad, km]: */
/*                    0.500000        1.547727    -6356.238467 */
/*               Velocity [rad/s, rad/s, km/s]: */
/*                    0.100000       -0.004721       -0.195333 */

/*             Verification:  Cylindrical state */
/*               Position [km, rad, km]: */
/*                    1.000000        0.500000        0.500000 */
/*               Velocity [km/s, rad/s, km/s]: */
/*                    0.200000        0.100000       -0.200000 */

/* $ Restrictions */

/*     None. */

/* $ Literature_References */

/*     None. */

/* $ Author_and_Institution */

/*     S.C. Krening      (JPL) */
/*     B.V. Semenov      (JPL) */

/* $ Version */

/* -    SPICELIB Version 1.0.0  22-APR-2014 (SCK)(BVS) */

/* -& */
/* $ Index_Entries */

/*     state transformation between coordinate systems */
/*     convert state */

/* -& */

/*     SPICELIB functions */


/*     Local parameters */

/*     Potentially large numbers produced by transforming the */
/*     velocity using the Jacobian must not exceed DPMAX()/MARGIN: */


/*     The size of each coordinate system name must not exceed */
/*     CHSIZ characters. */


/*     NCOSYS is the number of coordinate systems supported by */
/*     this routine. */


/*     The following integer parameters represent the coordinate */
/*     systems supported by this routine. */


/*     Saved body name length. */


/*     Local variables */

/*     COSYS is the array of supported coordinate system names. */
/*     ISYSU and OSYSU are the input and output coordinate systems */
/*     from the user that are made insensitive to case or leading and */
/*     trailing spaces. */


/*     IPOS and IVEL are the input position and velocity translated */
/*     into rectangular. */


/*     For transformations including either geodetic or planetographic */
/*     coordinate systems, RADII is an array of the radii values */
/*     associated with the input body. These values will be loaded */
/*     from the kernel pool. */


/*     JACOBI is the Jacobian matrix that converts the velocity */
/*     coordinates between systems. */


/*     The flattening coefficient, F, is calculated when either */
/*     geodetic or planetographic coordinate systems are included */
/*     in the transformation. */


/*     SQTMP and TOOBIG are used to check for possible numeric */
/*     overflow situations. */


/*     BODYID and DIM are only used when the input or output coordinate */
/*     systems are geodetic or planetographic. The BODYID is the NAID ID */
/*     associated with the input body name. DIM is used while retrieving */
/*     the radii from the kernel pool. */


/*     ISYS and OSYS are the integer codes corresponding to the */
/*     input and output coordinate systems. I and J are iterators. */


/*     Saved name/ID item declarations. */


/*     Saved variables */


/*     Saved name/ID items. */


/*     Assign the names of the coordinate systems to a character */
/*     array in which each coordinate system name is located at */
/*     the index of the integer ID of the coordinate system. */


/*     Initial values. */


/*     There are three main sections of this routine: */

/*       1)  Error handling and initialization. */
/*       2)  Conversion of the input to rectangular coordinates. */
/*       3)  Conversion from rectangular to the output coordinates. */

/*     Error handling and initialization */
/*     ---------------------------------------------------------------- */

/*     Standard SPICE error handling. */

    if (return_()) {
	return 0;
    }
    chkin_("XFMSTA", (ftnlen)6);

/*     Initialization. */

    if (first) {

/*        Initialize counter. */

	zzctruin_(svctr1);
	first = FALSE_;
    }

/*     Remove initial and trailing spaces. */
/*     Convert the input coordinate systems to upper case. */

    ljucrs_(&c__0, icosys, isysu, icosys_len, (ftnlen)40);
    ljucrs_(&c__0, ocosys, osysu, ocosys_len, (ftnlen)40);

/*     Check to see if the input and output coordinate systems */
/*     provided by the user are acceptable. Store the integer */
/*     code of the input and output coordinate systems into */
/*     ISYS and OSYS. */

    isys = isrchc_(isysu, &c__6, cosys, (ftnlen)40, (ftnlen)40);
    osys = isrchc_(osysu, &c__6, cosys, (ftnlen)40, (ftnlen)40);

/*     If the coordinate systems are not acceptable, an error is */
/*     signaled. */

    if (isys == 0 || osys == 0) {
	if (isys == 0 && osys == 0) {

/*           Both the input and the output coordinate systems were not */
/*           recognized. */

	    setmsg_("Input coordinate system # and output coordinate system "
		    "# are not recognized.", (ftnlen)76);
	    errch_("#", icosys, (ftnlen)1, icosys_len);
	    errch_("#", ocosys, (ftnlen)1, ocosys_len);
	    sigerr_("SPICE(COORDSYSNOTREC)", (ftnlen)21);
	    chkout_("XFMSTA", (ftnlen)6);
	    return 0;
	} else if (isys == 0) {

/*           The input coordinate system was not recognized. */

	    setmsg_("Input coordinate system # was not recognized", (ftnlen)
		    44);
	    errch_("#", icosys, (ftnlen)1, icosys_len);
	    sigerr_("SPICE(COORDSYSNOTREC)", (ftnlen)21);
	    chkout_("XFMSTA", (ftnlen)6);
	    return 0;
	} else {

/*           The output coordinate system was not recognized. */

	    setmsg_("Output coordinate system # was not recognized", (ftnlen)
		    45);
	    errch_("#", ocosys, (ftnlen)1, ocosys_len);
	    sigerr_("SPICE(COORDSYSNOTREC)", (ftnlen)21);
	    chkout_("XFMSTA", (ftnlen)6);
	    return 0;
	}
    }

/*     If the input and output coordinate systems are equal, set the */
/*     output equal to the input since no conversion needs to take */
/*     place. */

    if (isys == osys) {
	vequg_(istate, &c__6, ostate);
	chkout_("XFMSTA", (ftnlen)6);
	return 0;
    }

/*     If converting to or from either geodetic or planetographic, the */
/*     NAIF ID must be found from the input body name BODY. If the */
/*     body name does not have a valid NAIF ID code, an error is */
/*     signaled. If the NAIF ID is valid, the radii of the body are */
/*     located and the flattening coefficient is calculated. */

    if (osys == 5 || osys == 6 || isys == 5 || isys == 6) {

/*        Find the NAIF ID code */

	zzbods2c_(svctr1, svbody, &svbdid, &svfnd1, body, &bodyid, &found, (
		ftnlen)36, body_len);

/*        If the body's name was found, find the body's radii and */
/*        compute flattening coefficient. Otherwise, signal an error. */

	if (found) {
	    bodvcd_(&bodyid, "RADII", &c__3, &dim, radii, (ftnlen)5);
	    if (failed_()) {
		chkout_("XFMSTA", (ftnlen)6);
		return 0;
	    }

/*           If either radius is less than or equal to zero, an error is */
/*           signaled. */

	    if (radii[2] <= 0. || radii[0] <= 0.) {
		setmsg_("At least one radii is less than or equal to zero. T"
			"he equatorial radius has a value of # and the polar "
			"radius has has a value of #.", (ftnlen)131);
		errdp_("#", radii, (ftnlen)1);
		errdp_("#", &radii[2], (ftnlen)1);
		sigerr_("SPICE(INVALIDRADIUS)", (ftnlen)20);
		chkout_("XFMSTA", (ftnlen)6);
		return 0;
	    }

/*           If the difference of the equatorial and polar radii */
/*           divided by the equatorial radius is greater than DPMAX, */
/*           a numeric overflow may occur, so an error is signaled. */

	    if (sqrt((d__1 = radii[0] - radii[2], abs(d__1))) / sqrt((abs(
		    radii[0]))) >= sqrt(dpmax_())) {
		setmsg_("The equatorial radius for # has a value of # and a "
			"polar radius of #. The flattening coefficient cannot"
			" be calculated due to numeric overflow.", (ftnlen)142)
			;
		errch_("#", body, (ftnlen)1, body_len);
		errdp_("#", radii, (ftnlen)1);
		errdp_("#", &radii[2], (ftnlen)1);
		sigerr_("SPICE(INVALIDRADIUS)", (ftnlen)20);
		chkout_("XFMSTA", (ftnlen)6);
		return 0;
	    }
	    f = (radii[0] - radii[2]) / radii[0];
	} else {
	    setmsg_("The input body name # does not have a valid NAIF ID cod"
		    "e.", (ftnlen)57);
	    errch_("#", body, (ftnlen)1, body_len);
	    sigerr_("SPICE(IDCODENOTFOUND)", (ftnlen)21);
	    chkout_("XFMSTA", (ftnlen)6);
	    return 0;
	}
    }

/*     Conversion of the input to rectangular coordinates */
/*     ---------------------------------------------------------------- */

/*     First, the position and velocity coordinates will be converted */
/*     into rectangular coordinates. If the input system is not */
/*     rectangular, then the velocity coordinates must be translated */
/*     into rectangular using the Jacobian. If the input system is */
/*     rectangular, then the input state must simply be saved into IPOS */
/*     and IVEL. */

/*     TOOBIG is used for preventing numerical overflow. The square */
/*     roots of values are used to safely check if overflow will occur. */

    toobig = sqrt(dpmax_() / 100.);
    if (isys != 1) {

/*        To rectangular... */

	if (isys == 2) {

/*                  ... from cylindrical */

	    cylrec_(istate, &istate[1], &istate[2], ipos);
	    drdcyl_(istate, &istate[1], &istate[2], jacobi);
	} else if (isys == 3) {

/*                  ... from latitudinal */

	    latrec_(istate, &istate[1], &istate[2], ipos);
	    drdlat_(istate, &istate[1], &istate[2], jacobi);
	} else if (isys == 4) {

/*                  ... from spherical */

	    sphrec_(istate, &istate[1], &istate[2], ipos);
	    drdsph_(istate, &istate[1], &istate[2], jacobi);
	} else if (isys == 5) {

/*                  ... from geodetic */

	    georec_(istate, &istate[1], &istate[2], radii, &f, ipos);
	    if (failed_()) {
		chkout_("XFMSTA", (ftnlen)6);
		return 0;
	    }
	    drdgeo_(istate, &istate[1], &istate[2], radii, &f, jacobi);
	} else if (isys == 6) {

/*                  ... from planetographic */

	    pgrrec_(body, istate, &istate[1], &istate[2], radii, &f, ipos, 
		    body_len);
	    if (failed_()) {
		chkout_("XFMSTA", (ftnlen)6);
		return 0;
	    }
	    drdpgr_(body, istate, &istate[1], &istate[2], radii, &f, jacobi, 
		    body_len);
	} else {
	    setmsg_("This error should never occur. This is an intermediate "
		    "step in which a non-rectangular input state should be tr"
		    "ansferred to rectangular.  The input coordinate system i"
		    "s not recognized, yet was not caught by an earlier check."
		    , (ftnlen)224);
	    sigerr_("SPICE(BUG1)", (ftnlen)11);
	    chkout_("XFMSTA", (ftnlen)6);
	    return 0;
	}

/*        Some DRD* routines are not error free. Be safe and check */
/*        FAILED to not use un-initialized JACOBI. */

	if (failed_()) {
	    chkout_("XFMSTA", (ftnlen)6);
	    return 0;
	}

/*        If the multiplication of the Jacobian and velocity can cause */
/*        overflow, signal an error. */

	for (i__ = 1; i__ <= 3; ++i__) {
	    for (j = 1; j <= 3; ++j) {
		sqtmp = sqrt((d__1 = jacobi[(i__1 = i__ + j * 3 - 4) < 9 && 0 
			<= i__1 ? i__1 : s_rnge("jacobi", i__1, "xfmsta_", (
			ftnlen)1054)], abs(d__1))) * sqrt((d__2 = istate[(
			i__2 = j + 2) < 6 && 0 <= i__2 ? i__2 : s_rnge("ista"
			"te", i__2, "xfmsta_", (ftnlen)1054)], abs(d__2)));
		if (sqtmp > toobig) {
		    setmsg_("The product of the Jacobian and velocity may ca"
			    "use numeric overflow.", (ftnlen)68);
		    sigerr_("SPICE(NUMERICOVERFLOW)", (ftnlen)22);
		    chkout_("XFMSTA", (ftnlen)6);
		    return 0;
		}
	    }
	}

/*        Transform the velocity into rectangular coordinates. */

	mxv_(jacobi, &istate[3], ivel);
    } else if (isys == 1) {

/*        If the input coordinate system is rectangular, the input */
/*        position does not need to be translated into rectangular. */

	vequ_(istate, ipos);
	vequ_(&istate[3], ivel);
    } else {
	setmsg_("This error should never occur. This is an ELSE statement. I"
		"f the input coordinate system is not rectangular, the IF sho"
		"uld be executed. If the input coordinate system is rectangul"
		"ar, the ELSE IF should be executed.", (ftnlen)214);
	sigerr_("SPICE(BUG2)", (ftnlen)11);
	chkout_("XFMSTA", (ftnlen)6);
	return 0;
    }

/*     Conversion from rectangular into the output coordinates */
/*     ---------------------------------------------------------------- */

/*     Convert to the output coordinate system. If the output */
/*     coordinate system is not rectangular, four calculations must */
/*     be made: */

/*       1)  Verify the position and velocity are not along the z-axis. */
/*           If the position and velocity are along the z-axis, the */
/*           velocity can still be converted even though the */
/*           Jacobian is not defined. If the position is along the */
/*           z-axis but the velocity is not, the velocity cannot be */
/*           converted to the output coordinate system. */

/*       2)  Calculate the Jacobian from rectangular to the output */
/*           coordinate system and verify the product of the Jacobian */
/*           and velocity will not cause numeric overflow. */

/*       3)  Transform the position to the output coordinate system. */

/*       4)  Transform the velocity to the output coordinates using */
/*           the Jacobian and the rectangular velocity IVEL. */

    if (osys != 1) {

/*        From rectangular for the case when the input position is along */
/*        the z-axis ... */

	if (abs(ipos[0]) + abs(ipos[1]) == 0.) {
	    if (abs(ivel[0]) + abs(ivel[1]) == 0.) {

/*              If the velocity is along the z-axis, then the velocity */
/*              can be computed in the output coordinate frame even */
/*              though the Jacobian is not defined. */

		if (osys == 2) {

/*                  ... to cylindrical */

		    vpack_(&c_b56, &c_b56, &ivel[2], &ostate[3]);
		    reccyl_(ipos, ostate, &ostate[1], &ostate[2]);
		} else if (osys == 3) {

/*                  ... to latitudinal */

		    vpack_(&ivel[2], &c_b56, &c_b56, &ostate[3]);
		    reclat_(ipos, ostate, &ostate[1], &ostate[2]);
		} else if (osys == 4) {

/*                  ... to spherical */

		    vpack_(&ivel[2], &c_b56, &c_b56, &ostate[3]);
		    recsph_(ipos, ostate, &ostate[1], &ostate[2]);
		} else if (osys == 5) {

/*                  ... to geodetic */

		    vpack_(&c_b56, &c_b56, &ivel[2], &ostate[3]);
		    recgeo_(ipos, radii, &f, ostate, &ostate[1], &ostate[2]);
		} else if (osys == 6) {

/*                  ... to planetographic */

		    vpack_(&c_b56, &c_b56, &ivel[2], &ostate[3]);
		    recpgr_(body, ipos, radii, &f, ostate, &ostate[1], &
			    ostate[2], body_len);
		} else {
		    setmsg_("This error should never occur. This is an inter"
			    "mediate step in which a position and velocity al"
			    "ong the z-axis are converted to a non-rectangula"
			    "r coordinate system from rectangular. The output"
			    " coordinate system is not recognized, yet was no"
			    "t caught by an earlier check.", (ftnlen)268);
		    sigerr_("SPICE(BUG3)", (ftnlen)11);
		    chkout_("XFMSTA", (ftnlen)6);
		    return 0;
		}

/*              The output state has been calculated for the special */
/*              case of the position and velocity existing along the */
/*              z-axis. */

		chkout_("XFMSTA", (ftnlen)6);
		return 0;
	    } else {

/*              The Jacobian is undefined and the velocity cannot be */
/*              converted since it is not along the z-axis. */
/*              Signal an error. */

		setmsg_("Invalid input state: z axis.", (ftnlen)28);
		sigerr_("SPICE(INVALIDSTATE)", (ftnlen)19);
		chkout_("XFMSTA", (ftnlen)6);
		return 0;
	    }
	}

/*        From rectangular for cases when the input position is not along */
/*        the z-axis ... */

	if (osys == 2) {

/*                  ... to cylindrical */

	    dcyldr_(ipos, &ipos[1], &ipos[2], jacobi);
	    reccyl_(ipos, ostate, &ostate[1], &ostate[2]);
	} else if (osys == 3) {

/*                  ... to latitudinal */

	    dlatdr_(ipos, &ipos[1], &ipos[2], jacobi);
	    reclat_(ipos, ostate, &ostate[1], &ostate[2]);
	} else if (osys == 4) {

/*                  ... to spherical */

	    dsphdr_(ipos, &ipos[1], &ipos[2], jacobi);
	    recsph_(ipos, ostate, &ostate[1], &ostate[2]);
	} else if (osys == 5) {

/*                  ... to geodetic */

	    dgeodr_(ipos, &ipos[1], &ipos[2], radii, &f, jacobi);
	    recgeo_(ipos, radii, &f, ostate, &ostate[1], &ostate[2]);
	} else if (osys == 6) {

/*                  ... to planetographic */

	    dpgrdr_(body, ipos, &ipos[1], &ipos[2], radii, &f, jacobi, 
		    body_len);
	    recpgr_(body, ipos, radii, &f, ostate, &ostate[1], &ostate[2], 
		    body_len);
	} else {
	    setmsg_("This error should never occur. This is an intermediate "
		    "step in which a state is converted to a non-rectangular "
		    "coordinate system from rectangular. The output coordinat"
		    "e system is not recognized, yet was not caught by an ear"
		    "lier check.", (ftnlen)234);
	    sigerr_("SPICE(BUG4)", (ftnlen)11);
	    chkout_("XFMSTA", (ftnlen)6);
	    return 0;
	}

/*        Many D*DR and REC* routines are not error free. Be safe and */
/*        check FAILED to not use un-initialized JACOBI. */

	if (failed_()) {
	    chkout_("XFMSTA", (ftnlen)6);
	    return 0;
	}

/*        If the multiplication of the Jacobian and velocity can cause */
/*        overflow, signal an error. */

	for (i__ = 1; i__ <= 3; ++i__) {
	    for (j = 1; j <= 3; ++j) {
		sqtmp = sqrt((d__1 = jacobi[(i__1 = i__ + j * 3 - 4) < 9 && 0 
			<= i__1 ? i__1 : s_rnge("jacobi", i__1, "xfmsta_", (
			ftnlen)1314)], abs(d__1))) * sqrt((d__2 = ivel[(i__2 =
			 j - 1) < 3 && 0 <= i__2 ? i__2 : s_rnge("ivel", i__2,
			 "xfmsta_", (ftnlen)1314)], abs(d__2)));
		if (sqtmp > toobig) {
		    setmsg_("The product of the Jacobian and velocity may ca"
			    "use numeric overflow.", (ftnlen)68);
		    sigerr_("SPICE(NUMERICOVERFLOW)", (ftnlen)22);
		    chkout_("XFMSTA", (ftnlen)6);
		    return 0;
		}
	    }
	}

/*        Calculate the velocity in the output coordinate system. */

	mxv_(jacobi, ivel, &ostate[3]);
    } else if (osys == 1) {

/*        If the output coordinate system is rectangular, the position */
/*        and velocity components of the output state are set equal to */
/*        the rectangular IPOS and IVEL, respectively, because the */
/*        components have already been converted to rectangular. */

	vequ_(ipos, ostate);
	vequ_(ivel, &ostate[3]);
    } else {
	setmsg_("This error should never occur. This is an ELSE statement. I"
		"f the output coordinate system is not rectangular, the IF sh"
		"ould be executed. If the output coordinate system is rectang"
		"ular, the ELSE IF should be executed.", (ftnlen)216);
	sigerr_("SPICE(BUG5)", (ftnlen)11);
	chkout_("XFMSTA", (ftnlen)6);
	return 0;
    }
    chkout_("XFMSTA", (ftnlen)6);
    return 0;
} /* xfmsta_ */
コード例 #4
0
ファイル: et2lst.c プロジェクト: Dbelsa/coft
/* $Procedure ET2LST ( ET to Local Solar Time ) */
/* Subroutine */ int et2lst_(doublereal *et, integer *body, doublereal *
	long__, char *type__, integer *hr, integer *mn, integer *sc, char *
	time, char *ampm, ftnlen type_len, ftnlen time_len, ftnlen ampm_len)
{
    /* System generated locals */
    address a__1[5], a__2[7];
    integer i__1[5], i__2[7];
    doublereal d__1;

    /* Builtin functions */
    integer s_cmp(char *, char *, ftnlen, ftnlen);
    /* Subroutine */ int s_copy(char *, char *, ftnlen, ftnlen), s_cat(char *,
	     char **, integer *, integer *, ftnlen);

    /* Local variables */
    doublereal rate, slat, mins;
    char h__[2], m[2];
    integer n;
    doublereal q;
    char s[2];
    doublereal angle;
    char frame[32];
    doublereal range;
    extern /* Subroutine */ int chkin_(char *, ftnlen), ucase_(char *, char *,
	     ftnlen, ftnlen), errch_(char *, char *, ftnlen, ftnlen), dpfmt_(
	    doublereal *, char *, char *, ftnlen, ftnlen);
    logical found;
    extern /* Subroutine */ int repmi_(char *, char *, integer *, char *, 
	    ftnlen, ftnlen, ftnlen);
    doublereal state[6], slong;
    extern /* Subroutine */ int spkez_(integer *, doublereal *, char *, char *
	    , integer *, doublereal *, doublereal *, ftnlen, ftnlen);
    doublereal hours;
    extern /* Subroutine */ int ljust_(char *, char *, ftnlen, ftnlen);
    extern doublereal twopi_(void);
    extern /* Subroutine */ int bodc2n_(integer *, char *, logical *, ftnlen);
    extern doublereal pi_(void);
    char bodnam[36];
    doublereal lt;
    integer frcode;
    extern /* Subroutine */ int cidfrm_(integer *, integer *, char *, logical 
	    *, ftnlen);
    extern doublereal brcktd_(doublereal *, doublereal *, doublereal *);
    extern /* Subroutine */ int reclat_(doublereal *, doublereal *, 
	    doublereal *, doublereal *), rmaind_(doublereal *, doublereal *, 
	    doublereal *, doublereal *);
    doublereal secnds;
    extern /* Subroutine */ int pgrrec_(char *, doublereal *, doublereal *, 
	    doublereal *, doublereal *, doublereal *, doublereal *, ftnlen);
    char bpmkwd[32];
    integer hrampm;
    doublereal tmpang;
    extern /* Subroutine */ int gdpool_(char *, integer *, integer *, integer 
	    *, doublereal *, logical *, ftnlen);
    char amorpm[4];
    doublereal tmpsec;
    extern /* Subroutine */ int sigerr_(char *, ftnlen), chkout_(char *, 
	    ftnlen), dtpool_(char *, logical *, integer *, char *, ftnlen, 
	    ftnlen), setmsg_(char *, ftnlen), errint_(char *, integer *, 
	    ftnlen);
    doublereal mylong, spoint[3];
    extern logical return_(void);
    char kwtype[1];
    extern /* Subroutine */ int intstr_(integer *, char *, ftnlen);
    char mytype[32];
    doublereal lat;

/* $ Abstract */

/*     Given an ephemeris epoch ET, compute the local solar time for */
/*     an object on the surface of a body at a specified longitude. */

/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */

/* $ Required_Reading */

/*     TIME */

/* $ Keywords */

/*     TIME */

/* $ Declarations */
/* $ Brief_I/O */

/*     VARIABLE  I/O  DESCRIPTION */
/*     --------  ---  -------------------------------------------------- */
/*     ET         I   Epoch in seconds past J2000 epoch */
/*     BODY       I   ID-code of the body of interest */
/*     LONG       I   Longitude of surface point (RADIANS) */
/*     TYPE       I   Type of longitude 'PLANETOCENTRIC', etc. */
/*     HR         O   Local hour on a "24 hour" clock */
/*     MN         O   Minutes past the hour */
/*     SC         O   Seconds past the minute */
/*     TIME       O   String giving local time on 24 hour clock */
/*     AMPM       O   String giving time on A.M./ P.M. scale */

/* $ Detailed_Input */

/*     ET         is the epoch expressed in TDB seconds past */
/*                the J2000 epoch at which a local time is desired. */

/*     BODY       is the NAIF ID-code of a body on which local */
/*                time is to be measured. */

/*     LONG       is the longitude (either planetocentric or */
/*                planetographic) in radians of the site on the */
/*                surface of body for which local time should be */
/*                computed. */

/*     TYPE       is the form of longitude supplied by the variable */
/*                LONG.  Allowed values are 'PLANETOCENTRIC' and */
/*                'PLANETOGRAPHIC'.  Note the case of the letters */
/*                in TYPE is insignificant.  Both 'PLANETOCENTRIC' */
/*                and 'planetocentric' are recognized. */

/* $ Detailed_Output */

/*     HR         is the local "hour" of the site specified at the */
/*                epoch ET. Note that an "hour" of local time does not */
/*                have the same duration as an hour measured by */
/*                conventional clocks.  It is simply a representation */
/*                of an angle. See the "Particulars" section for a more */
/*                complete discussion of the meaning of local time. */

/*     MN         is the number of "minutes" past the hour of the */
/*                local time of the site at the epoch ET. Again note */
/*                that a "local minute" is not the same as a minute */
/*                you would measure with conventional clocks. */

/*     SC         is the number of "seconds" past the minute of the */
/*                local time of the site at the epoch ET.  Again note */
/*                that a "local second" is not the same as a second */
/*                you would measure with conventional clocks. */

/*     TIME       is a string expressing the local time */
/*                on a "24 hour" local clock. */

/*     AMPM       is a string expressing the local time on a "12 hour" */
/*                local clock together with the traditional AM/PM */
/*                label to indicate whether the sun has crossed */
/*                the local zenith meridian. */

/* $ Parameters */

/*     None. */

/* $ Exceptions */

/*     1) This routine defines local solar time for any point on the */
/*        surface of the Sun to be 12:00:00 noon. */

/*     2) If the TYPE of the coordinates is not recognized, the */
/*        error 'SPICE(UNKNOWNSYSTEM)' will be signaled. */

/*     3) If the body-fixed frame to associate with BODY cannot be */
/*        determined, the error 'SPICE(CANTFINDFRAME)' is signaled. */

/*     4) If insufficient data is available to compute the */
/*        location of the sun in body-fixed coordinates, the */
/*        error will be diagnosed by a routine called by this one. */

/*     5) If the BODY#_PM keyword required to determine the body */
/*        rotation sense is not found in the POOL or if it is found but */
/*        is not a numeric keyword with at least two elements, the error */
/*        'SPICE(CANTGETROTATIONTYPE)' is signaled. */

/* $ Files */

/*     Suitable SPK and PCK files must be loaded prior to calling this */
/*     routine so that the body-fixed position of the sun relative to */
/*     BODY can be computed. The PCK files must contain the standard */
/*     BODY#_PM keyword need by this routine to determine the body */
/*     rotation sense. */

/*     When the input longitude is planetographic, the default */
/*     interpretation of this value can be overridden using the optional */
/*     kernel variable */

/*        BODY<body ID>_PGR_POSITIVE_LON */

/*     which is normally defined via loading a text kernel. */

/* $ Particulars */

/*     This routine returns the local solar time at a user */
/*     specified location on a user specified body. */

/*     Let SUNLNG be the planetocentric longitude (in degrees) of */
/*     the sun as viewed from the center of the body of interest. */

/*     Let SITLNG be the planetocentric longitude (in degrees) of */
/*     the site for which local time is desired. */

/*     We define local time to be 12 + (SITLNG - SUNLNG)/15 */

/*     (where appropriate care is taken to map ( SITLNG - SUNLNG ) */
/*     into the range from -180 to 180). */

/*     Using this definition, we see that from the point of view */
/*     of this routine, local solar time is simply a measure of angles */
/*     between meridians on the surface of a body.  Consequently, */
/*     this routine is not appropriate for computing "local times" */
/*     in the sense of Pacific Standard Time.   For computing times */
/*     relative to standard time zones on earth, see the routines */
/*     TIMOUT and STR2ET. */


/*     Regarding planetographic longitude */
/*     ---------------------------------- */

/*     In the planetographic coordinate system, longitude is defined */
/*     using the spin sense of the body.  Longitude is positive to the */
/*     west if the spin is prograde and positive to the east if the spin */
/*     is retrograde.  The spin sense is given by the sign of the first */
/*     degree term of the time-dependent polynomial for the body's prime */
/*     meridian Euler angle "W":  the spin is retrograde if this term is */
/*     negative and prograde otherwise.  For the sun, planets, most */
/*     natural satellites, and selected asteroids, the polynomial */
/*     expression for W may be found in a SPICE PCK kernel. */

/*     The earth, moon, and sun are exceptions: planetographic longitude */
/*     is measured positive east for these bodies. */

/*     If you wish to override the default sense of positive */
/*     planetographic longitude for a particular body, you can do so by */
/*     defining the kernel variable */

/*        BODY<body ID>_PGR_POSITIVE_LON */

/*     where <body ID> represents the NAIF ID code of the body. This */
/*     variable may be assigned either of the values */

/*        'WEST' */
/*        'EAST' */

/*     For example, you can have this routine treat the longitude */
/*     of the earth as increasing to the west using the kernel */
/*     variable assignment */

/*        BODY399_PGR_POSITIVE_LON = 'WEST' */

/*     Normally such assignments are made by placing them in a text */
/*     kernel and loading that kernel via FURNSH. */


/* $ Examples */

/*     The following code fragment illustrates how you */
/*     could print the local time at a site on Mars with */
/*     planetographic longitude 326.17 deg E at epoch ET. */

/*     (This example assumes all required SPK and PCK files have */
/*     been loaded). */

/*     Convert the longitude to radians, set the type of the longitude */
/*     and make up a mnemonic for Mars' ID-code. */

/*     LONG = 326.17 * RPD() */
/*     TYPE = 'PLANETOGRAPHIC' */
/*     MARS = 499 */

/*     CALL ET2LST ( ET, MARS, LONG, TYPE, HR, MN, SC, TIME, AMPM ) */

/*     WRITE (*,*) 'The local time at Mars 326.17 degrees E ' */
/*     WRITE (*,*) 'planetographic longitude is: ', AMPM */

/* $ Restrictions */

/*     This routine relies on being able to determine the name */
/*     of the body-fixed frame associated with BODY through the */
/*     frames subsystem.  If the BODY specified is NOT one of the */
/*     nine planets or their satellites, you will need to load */
/*     an appropriate frame definition kernel that contains */
/*     the relationship between the body id and the body-fixed frame */
/*     name.  See the FRAMES required reading for more details */
/*     on specifying this relationship. */

/*     The routine determines the body rotation sense using the PCK */
/*     keyword BODY#_PM. Therefore, you will need to a text PCK file */
/*     defining the complete set of the standard PCK body rotation */
/*     keywords for the body of interest. The text PCK file must be */
/*     loaded independently of whether a binary PCK file providing */
/*     rotation data for the same body is loaded or not. */

/*     Although it is not currently the case for any of the Solar System */
/*     bodies, it is possible that the retrograde rotation rate of a */
/*     body would be slower than the orbital rate of the body rotation */
/*     around the Sun. The routine does not account for such cases; for */
/*     them it will compute incorrect the local time progressing */
/*     backwards. */

/* $ Literature_References */

/*     None. */

/* $ Author_and_Institution */

/*     W.L. Taber      (JPL) */

/* $ Version */

/* -    SPICELIB Version 3.0.2, 18-APR-2014 (BVS) */

/*        Minor edits to long error messages. */

/* -    SPICELIB Version 3.0.1, 09-SEP-2009 (EDW) */

/*        Header edits: deleted a spurious C$ marker from the */
/*        "Detailed_Output" section. The existence of the marker */
/*        caused a failure in the HTML documentation creation script. */

/*        Deleted the "Revisions" section as it contained several */
/*        identical entries from the "Version" section. */

/*        Corrected order of header sections. */

/* -    SPICELIB Version 3.0.0, 28-OCT-2006 (BVS) */

/*        Bug fix: incorrect computation of the local time for the */
/*        bodies with the retrograde rotation causing the local time to */
/*        flow backwards has been fixed. The local time for all types of */
/*        bodies now progresses as expected -- midnight, increasing AM */
/*        hours, noon, increasing PM hours, next midnight, and so on. */

/* -    SPICELIB Version 2.0.0, 03-NOV-2005 (NJB) */

/*        Bug fix:  treatment of planetographic longitude has been */
/*        updated to be consistent with the SPICE planetographic/ */
/*        rectangular coordinate conversion routines.  The effect of */
/*        this change is that the default sense of positive longitude */
/*        for the moon is now east; also, the default sense of positive */
/*        planetographic longitude now may be overridden for any body */
/*        (see Particulars above). */

/*        Updated to remove non-standard use of duplicate arguments */
/*        in RMAIND calls. */

/* -    SPICELIB Version 1.1.0, 24-MAR-1998 (WLT) */

/*        The integer variable SUN was never initialized in the */
/*        previous version of the routine.  Now it is set to */
/*        the proper value of 10. */

/* -    SPICELIB Version 1.0.0, 9-JUL-1997 (WLT) */


/* -& */
/* $ Index_Entries */

/*     Compute the local time for a point on a body. */

/* -& */

/*     SPICELIB Functions */


/*     Local parameters */



/*     Local Variables */


/*     Standard SPICE error handling. */

    if (return_()) {
	return 0;
    }
    chkin_("ET2LST", (ftnlen)6);
    ljust_(type__, mytype, type_len, (ftnlen)32);
    ucase_(mytype, mytype, (ftnlen)32, (ftnlen)32);
    if (s_cmp(mytype, "PLANETOGRAPHIC", (ftnlen)32, (ftnlen)14) == 0) {

/*        Find planetocentric longitude corresponding to the input */
/*        longitude.  We first represent in rectangular coordinates */
/*        a surface point having zero latitude, zero altitude, and */
/*        the input planetographic longitude. We then find the */
/*        planetocentric longitude of this point. */

/*        Since PGRREC accepts a body name, map the input code to */
/*        a name, if possible.  Otherwise, just convert the input code */
/*        to a string. */

	bodc2n_(body, bodnam, &found, (ftnlen)36);
	if (! found) {
	    intstr_(body, bodnam, (ftnlen)36);
	}

/*        Convert planetographic coordinates to rectangular coordinates. */
/*        All we care about here is longitude.  Set the other inputs */
/*        as follows: */

/*            Latitude          = 0 */
/*            Altitude          = 0 */
/*            Equatorial radius = 1 */
/*            Flattening factor = 0 */

	pgrrec_(bodnam, long__, &c_b4, &c_b4, &c_b6, &c_b4, spoint, (ftnlen)
		36);

/*        The output MYLONG is planetocentric longitude.  The other */
/*        outputs are not used.  Note that the variable RANGE appears */
/*        later in another RECLAT call; it's not used after that. */

	reclat_(spoint, &range, &mylong, &lat);
    } else if (s_cmp(mytype, "PLANETOCENTRIC", (ftnlen)32, (ftnlen)14) == 0) {
	mylong = *long__;
    } else {
	setmsg_("The coordinate system '#' is not a recognized system of lon"
		"gitude.  The recognized systems are 'PLANETOCENTRIC' and 'PL"
		"ANETOGRAPHIC'. ", (ftnlen)134);
	errch_("#", type__, (ftnlen)1, type_len);
	sigerr_("SPICE(UNKNOWNSYSTEM)", (ftnlen)20);
	chkout_("ET2LST", (ftnlen)6);
	return 0;
    }

/*     It's always noon on the surface of the sun. */

    if (*body == 10) {
	*hr = 12;
	*mn = 0;
	*sc = 0;
	s_copy(time, "12:00:00", time_len, (ftnlen)8);
	s_copy(ampm, "12:00:00 P.M.", ampm_len, (ftnlen)13);
	chkout_("ET2LST", (ftnlen)6);
	return 0;
    }

/*     Get the body-fixed position of the sun. */

    cidfrm_(body, &frcode, frame, &found, (ftnlen)32);
    if (! found) {
	setmsg_("The body-fixed frame associated with body # could not be de"
		"termined.  This information needs to be \"loaded\" via a fra"
		"mes definition kernel.  See frames.req for more details. ", (
		ftnlen)174);
	errint_("#", body, (ftnlen)1);
	sigerr_("SPICE(CANTFINDFRAME)", (ftnlen)20);
	chkout_("ET2LST", (ftnlen)6);
	return 0;
    }
    spkez_(&c__10, et, frame, "LT+S", body, state, &lt, (ftnlen)32, (ftnlen)4)
	    ;
    reclat_(state, &range, &slong, &slat);
    angle = mylong - slong;

/*     Force the angle into the region from -PI to PI */

    d__1 = twopi_();
    rmaind_(&angle, &d__1, &q, &tmpang);
    angle = tmpang;
    if (angle > pi_()) {
	angle -= twopi_();
    }

/*     Get the rotation sense of the body and invert the angle if the */
/*     rotation sense is retrograde. Use the BODY#_PM PCK keyword to */
/*     determine the sense of the body rotation. */

    s_copy(bpmkwd, "BODY#_PM", (ftnlen)32, (ftnlen)8);
    repmi_(bpmkwd, "#", body, bpmkwd, (ftnlen)32, (ftnlen)1, (ftnlen)32);
    dtpool_(bpmkwd, &found, &n, kwtype, (ftnlen)32, (ftnlen)1);
    if (! found || *(unsigned char *)kwtype != 'N' || n < 2) {
	setmsg_("The rotation type for the body # could not be determined be"
		"cause the # keyword was either not found in the POOL or or i"
		"t was not of the expected type and/or dimension. This keywor"
		"d is usually provided via a planetary constants kernel. See "
		"pck.req for more details. ", (ftnlen)265);
	errint_("#", body, (ftnlen)1);
	errch_("#", bpmkwd, (ftnlen)1, (ftnlen)32);
	sigerr_("SPICE(CANTGETROTATIONTYPE)", (ftnlen)26);
	chkout_("ET2LST", (ftnlen)6);
	return 0;
    } else {

/*        If the rotation rate is negative, invert the angle. */

	gdpool_(bpmkwd, &c__2, &c__1, &n, &rate, &found, (ftnlen)32);
	if (rate < 0.) {
	    angle = -angle;
	}
    }

/*     Convert the angle to "angle seconds" before or after local noon. */

    secnds = angle * 86400. / twopi_();
    secnds = brcktd_(&secnds, &c_b32, &c_b33);

/*     Get the hour, and minutes components of the local time. */

    rmaind_(&secnds, &c_b34, &hours, &tmpsec);
    rmaind_(&tmpsec, &c_b35, &mins, &secnds);

/*     Construct the integer components of the local time. */

    *hr = (integer) hours + 12;
    *mn = (integer) mins;
    *sc = (integer) secnds;

/*     Set the A.M./P.M. components of local time. */

    if (*hr == 24) {
	*hr = 0;
	hrampm = 12;
	s_copy(amorpm, "A.M.", (ftnlen)4, (ftnlen)4);
    } else if (*hr > 12) {
	hrampm = *hr - 12;
	s_copy(amorpm, "P.M.", (ftnlen)4, (ftnlen)4);
    } else if (*hr == 12) {
	hrampm = 12;
	s_copy(amorpm, "P.M.", (ftnlen)4, (ftnlen)4);
    } else if (*hr == 0) {
	hrampm = 12;
	s_copy(amorpm, "A.M.", (ftnlen)4, (ftnlen)4);
    } else {
	hrampm = *hr;
	s_copy(amorpm, "A.M.", (ftnlen)4, (ftnlen)4);
    }

/*     Now construct the two strings we need. */

    hours = (doublereal) (*hr);
    mins = (doublereal) (*mn);
    secnds = (doublereal) (*sc);
    dpfmt_(&hours, "0x", h__, (ftnlen)2, (ftnlen)2);
    dpfmt_(&mins, "0x", m, (ftnlen)2, (ftnlen)2);
    dpfmt_(&secnds, "0x", s, (ftnlen)2, (ftnlen)2);
/* Writing concatenation */
    i__1[0] = 2, a__1[0] = h__;
    i__1[1] = 1, a__1[1] = ":";
    i__1[2] = 2, a__1[2] = m;
    i__1[3] = 1, a__1[3] = ":";
    i__1[4] = 2, a__1[4] = s;
    s_cat(time, a__1, i__1, &c__5, time_len);
    hours = (doublereal) hrampm;
    dpfmt_(&hours, "0x", h__, (ftnlen)2, (ftnlen)2);
/* Writing concatenation */
    i__2[0] = 2, a__2[0] = h__;
    i__2[1] = 1, a__2[1] = ":";
    i__2[2] = 2, a__2[2] = m;
    i__2[3] = 1, a__2[3] = ":";
    i__2[4] = 2, a__2[4] = s;
    i__2[5] = 1, a__2[5] = " ";
    i__2[6] = 4, a__2[6] = amorpm;
    s_cat(ampm, a__2, i__2, &c__7, ampm_len);
    chkout_("ET2LST", (ftnlen)6);
    return 0;
} /* et2lst_ */
コード例 #5
0
ファイル: recrad.c プロジェクト: Boxx-Obspm/DOCKing_System
/* $Procedure      RECRAD ( Rectangular coordinates to RA and DEC ) */
/* Subroutine */ int recrad_(doublereal *rectan, doublereal *range, 
	doublereal *ra, doublereal *dec)
{
    extern doublereal twopi_(void);
    extern /* Subroutine */ int reclat_(doublereal *, doublereal *, 
	    doublereal *, doublereal *);

/* $ Abstract */

/*     Convert rectangular coordinates to range, right ascension, */
/*     and declination. */

/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */

/* $ Required_Reading */

/*     None. */

/* $ Keywords */

/*     CONVERSION,  COORDINATES */

/* $ Declarations */
/* $ Brief_I/O */

/*     VARIABLE  I/O  DESCRIPTION */
/*     --------  ---  -------------------------------------------------- */
/*     RECTAN     I   Rectangular coordinates of a point. */
/*     RANGE      O   Distance of the point from the origin. */
/*     RA         O   Right ascension in radians. */
/*     DEC        O   Declination in radians. */

/* $ Detailed_Input */

/*     RECTAN     The rectangular coordinates of a point. */

/* $ Detailed_Output */

/*     RANGE      is the distance of the point from the origin. */

/*                The units associated with RANGE are those */
/*                associated with the input RECTAN. */


/*     RA         is the right ascension of RECTAN.  This is the angular */
/*                distance measured toward the east from the prime */
/*                meridian to the meridian containing the input point. */
/*                The direction of increasing right ascension is from */
/*                the +X axis towards the +Y axis. */

/*                RA is output in radians.  The range of RA is [0, 2*pi]. */


/*     DEC        is the declination of RECTAN.  This is the angle from */
/*                the XY plane of the ray from the origin through the */
/*                point. */

/*                DEC is output in radians.  The range of DEC is */
/*                [-pi/2, pi/2]. */

/* $ Parameters */

/*     None. */

/* $ Exceptions */

/*     Error free. */

/*     1) If the X and Y components of RECTAN are both zero, the */
/*        right ascension is set to zero. */

/*     2) If RECTAN is the zero vector, right ascension and declination */
/*        are both set to zero. */

/* $ Files */

/*     None. */

/* $ Particulars */

/*     This routine returns the range, right ascension, and declination */
/*     of a point specified in rectangular coordinates. */

/*     The output is defined by a distance from a central reference */
/*     point, an angle from a reference meridian, and an angle above */
/*     the equator of a sphere centered at the central reference */
/*     point. */

/* $ Examples */

/*     The following code fragment converts right ascension and */
/*     declination from the B1950 reference frame to the J2000 frame. */

/*        C */
/*        C     Convert RA and DEC to a 3-vector expressed in */
/*        C     the B1950 frame. */
/*        C */
/*              CALL RADREC ( 1.D0, RA, DEC, V1950 ) */
/*        C */
/*        C     We use the SPICELIB routine PXFORM to obtain the */
/*        C     transformation  matrix for converting vectors between */
/*        C     the B1950 and J2000 reference frames.  Since */
/*        C     both frames are inertial, the input time value we */
/*        C     supply to PXFORM is arbitrary.  We choose zero */
/*        C     seconds past the J2000 epoch. */
/*        C */
/*              CALL PXFORM ( 'B1950', 'J2000', 0.D0, MTRANS ) */
/*        C */
/*        C     Transform the vector to the J2000 frame. */
/*        C */
/*              CALL MXV ( MTRANS, V1950, V2000 ) */
/*        C */
/*        C     Find the RA and DEC of the J2000-relative vector. */
/*        C */
/*              CALL RECRAD ( V2000, R, RA, DEC ) */


/* $ Restrictions */

/*     None. */

/* $ Author_and_Institution */

/*     C.H. Acton      (JPL) */
/*     N.J. Bachman    (JPL) */
/*     H.A. Neilan     (JPL) */

/* $ Literature_References */

/*     None. */

/* $ Version */

/* -    SPICELIB Version 1.0.2, 30-JUL-2003 (NJB) (CHA) */

/*        Various header changes were made to improve clarity.  Some */
/*        minor header corrections were made. */

/* -    SPICELIB Version 1.0.1, 10-MAR-1992 (WLT) */

/*        Comment section for permuted index source lines was added */
/*        following the header. */

/* -    SPICELIB Version 1.0.0, 31-JAN-1990 (HAN) */

/* -& */
/* $ Index_Entries */

/*     rectangular coordinates to ra and dec */
/*     rectangular to right_ascension and declination */

/* -& */

/*     SPICELIB functions */


/*     Call the subroutine RECLAT to convert the rectangular coordinates */
/*     into latitudinal coordinates.  In RECLAT, the longitude ( which */
/*     is returned to this subroutine as RA ) ranges from - pi to pi */
/*     radians.   Because the right ascension ranges from zero to */
/*     two pi radians, whenever RA is negative two pi must be added to */
/*     it. */

    reclat_(rectan, range, ra, dec);
    if (*ra < 0.) {
	*ra += twopi_();
    }
    return 0;
} /* recrad_ */
コード例 #6
0
ファイル: zzhullax.c プロジェクト: Boxx-Obspm/DOCKing_System
/* $Procedure   ZZHULLAX ( Pyramidal FOV convex hull to FOV axis ) */
/* Subroutine */ int zzhullax_(char *inst, integer *n, doublereal *bounds, 
	doublereal *axis, ftnlen inst_len)
{
    /* System generated locals */
    integer bounds_dim2, i__1, i__2;
    doublereal d__1;

    /* Builtin functions */
    integer s_rnge(char *, integer, char *, integer);

    /* Local variables */
    extern /* Subroutine */ int vhat_(doublereal *, doublereal *);
    doublereal xvec[3], yvec[3], zvec[3];
    integer xidx;
    extern doublereal vsep_(doublereal *, doublereal *);
    integer next;
    logical pass1;
    integer i__, m;
    doublereal r__, v[3], delta;
    extern /* Subroutine */ int chkin_(char *, ftnlen), errch_(char *, char *,
	     ftnlen, ftnlen);
    logical found;
    extern /* Subroutine */ int errdp_(char *, doublereal *, ftnlen), vlcom_(
	    doublereal *, doublereal *, doublereal *, doublereal *, 
	    doublereal *);
    integer minix, maxix;
    doublereal trans[9]	/* was [3][3] */;
    extern /* Subroutine */ int ucrss_(doublereal *, doublereal *, doublereal 
	    *), vcrss_(doublereal *, doublereal *, doublereal *);
    extern logical vzero_(doublereal *);
    extern /* Subroutine */ int vrotv_(doublereal *, doublereal *, doublereal 
	    *, doublereal *);
    doublereal cp[3];
    extern doublereal pi_(void);
    logical ok;
    extern doublereal halfpi_(void);
    extern /* Subroutine */ int reclat_(doublereal *, doublereal *, 
	    doublereal *, doublereal *), sigerr_(char *, ftnlen);
    doublereal minlon;
    extern /* Subroutine */ int chkout_(char *, ftnlen);
    doublereal maxlon;
    extern /* Subroutine */ int vhatip_(doublereal *), vsclip_(doublereal *, 
	    doublereal *), setmsg_(char *, ftnlen), errint_(char *, integer *,
	     ftnlen);
    extern logical return_(void);
    doublereal lat, sep, lon;
    extern /* Subroutine */ int mxv_(doublereal *, doublereal *, doublereal *)
	    ;
    doublereal ray1[3], ray2[3];

/* $ Abstract */

/*     SPICE Private routine intended solely for the support of SPICE */
/*     routines.  Users should not call this routine directly due */
/*     to the volatile nature of this routine. */

/*     Identify a face of the convex hull of an instrument's */
/*     polygonal FOV, and use this face to generate an axis of the */
/*     FOV. */

/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */

/* $ Required_Reading */

/*     CK */
/*     FRAMES */
/*     GF */
/*     IK */
/*     KERNEL */

/* $ Keywords */

/*     FOV */
/*     GEOMETRY */
/*     INSTRUMENT */

/* $ Declarations */
/* $ Brief_I/O */

/*     VARIABLE  I/O  DESCRIPTION */
/*     --------  ---  -------------------------------------------------- */
/*     MARGIN     P   Minimum complement of FOV cone angle. */
/*     INST       I   Instrument name. */
/*     N          I   Number of FOV boundary vectors. */
/*     BOUNDS     I   FOV boundary vectors. */
/*     AXIS       O   Instrument FOV axis vector. */

/* $ Detailed_Input */

/*     INST       is the name of an instrument with which the field of */
/*                view (FOV) of interest is associated. This name is */
/*                used only to generate long error messages. */

/*     N          is the number of boundary vectors in the array */
/*                BOUNDS. */

/*     BOUNDS     is an array of N vectors emanating from a common */
/*                vertex and defining the edges of a pyramidal region in */
/*                three-dimensional space: this the region within the */
/*                FOV of the instrument designated by INST. The Ith */
/*                vector of BOUNDS resides in elements (1:3,I) of this */
/*                array. */

/*                The vectors contained in BOUNDS are called the */
/*                "boundary vectors" of the FOV. */

/*                The boundary vectors  must satisfy the constraints: */

/*                   1)  The boundary vectors  must be contained within */
/*                       a right circular cone of angular radius less */
/*                       than than (pi/2) - MARGIN radians; in other */
/*                       words, there must be a vector A such that all */
/*                       boundary vectors have angular separation from */
/*                       A of less than (pi/2)-MARGIN radians. */

/*                   2)  There must be a pair of vectors U, V in BOUNDS */
/*                       such that all other boundary vectors lie in */
/*                       the same half space bounded by the plane */
/*                       containing U and V. Furthermore, all other */
/*                       boundary vectors must have orthogonal */
/*                       projections onto a plane normal to this plane */
/*                       such that the projections have angular */
/*                       separation of at least 2*MARGIN radians from */
/*                       the plane spanned by U and V. */

/*                Given the first constraint above, there is plane PL */
/*                such that each of the set of rays extending the */
/*                boundary vectors intersects PL. (In fact, there is an */
/*                infinite set of such planes.) The boundary vectors */
/*                must be ordered so that the set of line segments */
/*                connecting the intercept on PL of the ray extending */
/*                the Ith vector to that of the (I+1)st, with the Nth */
/*                intercept connected to the first, form a polygon (the */
/*                "FOV polygon") constituting the intersection of the */
/*                FOV pyramid with PL. This polygon may wrap in either */
/*                the positive or negative sense about a ray emanating */
/*                from the FOV vertex and passing through the plane */
/*                region bounded by the FOV polygon. */

/*                The FOV polygon need not be convex; it may be */
/*                self-intersecting as well. */

/*                No pair of consecutive vectors in BOUNDS may be */
/*                linearly dependent. */

/*                The boundary vectors need not have unit length. */


/* $ Detailed_Output */

/*     AXIS       is a unit vector normal to a plane containing the */
/*                FOV polygon. All boundary vectors have angular */
/*                separation from AXIS of not more than */

/*                   ( pi/2 ) - MARGIN */

/*                radians. */

/*                This routine signals an error if it cannot find */
/*                a satisfactory value of AXIS. */

/* $ Parameters */

/*     MARGIN     is a small positive number used to constrain the */
/*                orientation of the boundary vectors. See the two */
/*                constraints described in the Detailed_Input section */
/*                above for specifics. */

/* $ Exceptions */

/*     1)  In the input vector count N is not at least 3, the error */
/*         SPICE(INVALIDCOUNT) is signaled. */

/*     2)  If any pair of consecutive boundary vectors has cross */
/*         product zero, the error SPICE(DEGENERATECASE) is signaled. */
/*         For this test, the first vector is considered the successor */
/*         of the Nth. */

/*     3)  If this routine can't find a face of the convex hull of */
/*         the set of boundary vectors such that this face satisfies */
/*         constraint (2) of the Detailed_Input section above, the */
/*         error SPICE(FACENOTFOUND) is signaled. */

/*     4)  If any boundary vectors have longitude too close to 0 */
/*         or too close to pi radians in the face frame (see discussion */
/*         of the search algorithm's steps 3 and 4 in Particulars */
/*         below), the respective errors SPICE(NOTSUPPORTED) or */
/*         SPICE(FOVTOOWIDE) are signaled. */

/*     5)  If any boundary vectors have angular separation of more than */
/*         (pi/2)-MARGIN radians from the candidate FOV axis, the */
/*         error SPICE(FOVTOOWIDE) is signaled. */

/* $ Files */

/*     The boundary vectors input to this routine are typically */
/*     obtained from an IK file. */

/* $ Particulars */

/*     Normally implementation is not discussed in SPICE headers, but we */
/*     make an exception here because this routine's implementation and */
/*     specification are deeply intertwined. */

/*     This routine produces an "axis" for a polygonal FOV using the */
/*     following approach: */

/*        1)  Test pairs of consecutive FOV boundary vectors to see */
/*            whether there's a pair such that the plane region bounded */
/*            by these vectors is */

/*            a)  part of the convex hull of the set of boundary vectors */

/*            b)  such that all other boundary vectors have angular */
/*                separation of at least MARGIN from the plane */
/*                containing these vectors */

/*            This search has O(N**2) run time dependency on N. */

/*            If this test produces a candidate face of the convex hull, */
/*            proceed to step 3. */


/*        2)  If step (1) fails, repeat the search for a candidate */
/*            convex hull face, but this time search over every pair of */
/*            distinct boundary vectors. */

/*            This search has O(N**3) run time dependency on N. */

/*            If this search fails, signal an error. */


/*        3)  Produce a set of basis vectors for a reference frame, */
/*            which we'll call the "face frame," using as the +X axis */
/*            the angle bisector of the vectors bounding the candidate */
/*            face, the +Y axis the inward normal vector to this face, */
/*            and the +Z axis completing a right-handed basis. */


/*        4)  Transform each boundary vector, other than the two vectors */
/*            defining the selected convex hull face, to the face frame */
/*            and compute the vector's longitude in that frame. Find the */
/*            maximum and minimum longitudes of the vectors in the face */
/*            frame. */

/*            If any vector's longitude is less than 2*MARGIN or greater */
/*            than pi - 2*MARGIN radians, signal an error. */


/*        5)  Let DELTA be the difference between pi and the maximum */
/*            longitude found in step (4). Rotate the +Y axis (which */
/*            points in the inward normal direction relative to the */
/*            selected face) by -DELTA/2 radians about the +Z axis of */
/*            the face frame. This rotation aligns the +Y axis with the */
/*            central longitude of the set of boundary vectors. The */
/*            resulting vector is our candidate FOV axis. */


/*        6)  Check the angular separation of the candidate FOV axis */
/*            against each boundary vector. If any vector has angular */
/*            separation of more than (pi/2)-MARGIN radians from the */
/*            axis, signal an error. */


/*     Note that there are reasonable FOVs that cannot be handled by the */
/*     algorithm described here. For example, any FOV whose cross */
/*     section is a regular convex polygon can be made unusable by */
/*     adding boundary vectors aligned with the angle bisectors of each */
/*     face of the pyramid defined by the FOV's boundary vectors. The */
/*     resulting set of boundary vectors has no face in its convex hull */
/*     such that all other boundary vectors have positive angular */
/*     separation from that face. */

/*     Because of this limitation, this algorithm should be used only */
/*     after a simple FOV axis-finding approach, such as using as the */
/*     FOV axis the average of the boundary vectors, has been tried */
/*     unsuccessfully. */

/*     Note that it's easy to construct FOVs where the average of the */
/*     boundary vectors doesn't yield a viable axis: a FOV of angular */
/*     width nearly equal to pi radians, with a sufficiently large */
/*     number of boundary vectors on one side and few boundary vectors */
/*     on the other, is one such example. This routine can find an */
/*     axis for many such intractable FOVs---that's why this routine */
/*     should be called after the simple approach fails. */

/* $ Examples */

/*     See SPICELIB private routine ZZFOVAXI. */

/* $ Restrictions */

/*     1) This is a SPICE private routine. User applications should not */
/*        call this routine. */

/*     2) There are "reasonable" polygonal FOVs that cannot be handled */
/*        by this routine. See the discussion in Particulars above. */

/* $ Literature_References */

/*     None. */

/* $ Author_and_Institution */

/*     N.J. Bachman    (JPL) */

/* $ Version */

/* -    SPICELIB 1.0.0, 05-MAR-2009 (NJB) */

/* -& */
/* $ Index_Entries */

/*     Create axis vector for polygonal FOV */

/* -& */

/*     SPICELIB functions */


/*     Local parameters */


/*     Local variables */

    /* Parameter adjustments */
    bounds_dim2 = *n;

    /* Function Body */
    if (return_()) {
	return 0;
    }
    chkin_("ZZHULLAX", (ftnlen)8);

/*     Nothing found yet. */

    found = FALSE_;
    xidx = 0;

/*     We must have at least 3 boundary vectors. */

    if (*n < 3) {
	setmsg_("Polygonal FOV requires at least 3 boundary vectors but numb"
		"er supplied for # was #.", (ftnlen)83);
	errch_("#", inst, (ftnlen)1, inst_len);
	errint_("#", n, (ftnlen)1);
	sigerr_("SPICE(INVALIDCOUNT)", (ftnlen)19);
	chkout_("ZZHULLAX", (ftnlen)8);
	return 0;
    }

/*     Find an exterior face of the pyramid defined by the */
/*     input boundary vectors. Since most polygonal FOVs will have */
/*     an exterior face bounded by two consecutive rays, we'll */
/*     try pairs of consecutive rays first. If this fails, we'll */
/*     try each pair of rays. */

    i__ = 1;
    while(i__ <= *n && ! found) {

/*        Set the index of the next ray. When we get to the */
/*        last boundary vector, the next ray is the first. */

	if (i__ == *n) {
	    next = 1;
	} else {
	    next = i__ + 1;
	}

/*        Find the cross product of the first ray with the */
/*        second. Depending on the ordering of the boundary */
/*        vectors, this could be an inward or outward normal, */
/*        in the case the current face is exterior. */

	vcrss_(&bounds[(i__1 = i__ * 3 - 3) < bounds_dim2 * 3 && 0 <= i__1 ? 
		i__1 : s_rnge("bounds", i__1, "zzhullax_", (ftnlen)408)], &
		bounds[(i__2 = next * 3 - 3) < bounds_dim2 * 3 && 0 <= i__2 ? 
		i__2 : s_rnge("bounds", i__2, "zzhullax_", (ftnlen)408)], cp);

/*        We insist on consecutive boundary vectors being */
/*        linearly independent. */

	if (vzero_(cp)) {
	    setmsg_("Polygonal FOV must have linearly independent consecutiv"
		    "e boundary but vectors at indices # and # have cross pro"
		    "duct equal to the zero vector. Instrument is #.", (ftnlen)
		    158);
	    errint_("#", &i__, (ftnlen)1);
	    errint_("#", &next, (ftnlen)1);
	    errch_("#", inst, (ftnlen)1, inst_len);
	    sigerr_("SPICE(DEGENERATECASE)", (ftnlen)21);
	    chkout_("ZZHULLAX", (ftnlen)8);
	    return 0;
	}

/*        See whether the other boundary vectors have angular */
/*        separation of at least MARGIN from the plane containing */
/*        the current face. */

	pass1 = TRUE_;
	ok = TRUE_;
	m = 1;
	while(m <= *n && ok) {

/*           Find the angular separation of CP and the Mth vector if the */
/*           latter is not an edge of the current face. */

	    if (m != i__ && m != next) {
		sep = vsep_(cp, &bounds[(i__1 = m * 3 - 3) < bounds_dim2 * 3 
			&& 0 <= i__1 ? i__1 : s_rnge("bounds", i__1, "zzhull"
			"ax_", (ftnlen)446)]);
		if (pass1) {

/*                 Adjust CP if necessary so that it points */
/*                 toward the interior of the pyramid. */

		    if (sep > halfpi_()) {

/*                    Invert the cross product vector and adjust SEP */
/*                    accordingly. Within this "M" loop, all other */
/*                    angular separations will be computed using the new */
/*                    value of CP. */

			vsclip_(&c_b20, cp);
			sep = pi_() - sep;
		    }
		    pass1 = FALSE_;
		}
		ok = sep < halfpi_() - 1e-12;
	    }
	    if (ok) {

/*              Consider the next boundary vector. */

		++m;
	    }
	}

/*        We've tested each boundary vector against the current face, or */
/*        else the loop terminated early because a vector with */
/*        insufficient angular separation from the plane containing the */
/*        face was found. */

	if (ok) {

/*           The current face is exterior. It's bounded by rays I and */
/*           NEXT. */

	    xidx = i__;
	    found = TRUE_;
	} else {

/*           Look at the next face of the pyramid. */

	    ++i__;
	}
    }

/*     If we didn't find an exterior face, we'll have to look at each */
/*     face bounded by a pair of rays, even if those rays are not */
/*     adjacent. (This can be a very slow process is N is large.) */

    if (! found) {
	i__ = 1;
	while(i__ <= *n && ! found) {

/*           Consider all ray pairs (I,NEXT) where NEXT > I. */

	    next = i__ + 1;
	    while(next <= *n && ! found) {

/*              Find the cross product of the first ray with the second. */
/*              If the current face is exterior, CP could be an inward */
/*              or outward normal, depending on the ordering of the */
/*              boundary vectors. */

		vcrss_(&bounds[(i__1 = i__ * 3 - 3) < bounds_dim2 * 3 && 0 <= 
			i__1 ? i__1 : s_rnge("bounds", i__1, "zzhullax_", (
			ftnlen)530)], &bounds[(i__2 = next * 3 - 3) < 
			bounds_dim2 * 3 && 0 <= i__2 ? i__2 : s_rnge("bounds",
			 i__2, "zzhullax_", (ftnlen)530)], cp);

/*              It's allowable for non-consecutive boundary vectors to */
/*              be linearly dependent, but if we have such a pair, */
/*              it doesn't define an exterior face. */

		if (! vzero_(cp)) {

/*                 The rays having direction vectors indexed I and NEXT */
/*                 define a semi-infinite sector of a plane that might */
/*                 be of interest. */

/*                 Check whether all of the boundary vectors that are */
/*                 not edges of the current face have angular separation */
/*                 of at least MARGIN from the plane containing the */
/*                 current face. */

		    pass1 = TRUE_;
		    ok = TRUE_;
		    m = 1;
		    while(m <= *n && ok) {

/*                    Find the angular separation of CP and the Mth */
/*                    vector if the latter is not an edge of the current */
/*                    face. */

			if (m != i__ && m != next) {
			    sep = vsep_(cp, &bounds[(i__1 = m * 3 - 3) < 
				    bounds_dim2 * 3 && 0 <= i__1 ? i__1 : 
				    s_rnge("bounds", i__1, "zzhullax_", (
				    ftnlen)560)]);
			    if (pass1) {

/*                          Adjust CP if necessary so that it points */
/*                          toward the interior of the pyramid. */

				if (sep > halfpi_()) {

/*                             Invert the cross product vector and */
/*                             adjust SEP accordingly. Within this "M" */
/*                             loop, all other angular separations will */
/*                             be computed using the new value of CP. */

				    vsclip_(&c_b20, cp);
				    sep = pi_() - sep;
				}
				pass1 = FALSE_;
			    }
			    ok = sep < halfpi_() - 1e-12;
			}
			if (ok) {

/*                       Consider the next boundary vector. */

			    ++m;
			}
		    }

/*                 We've tested each boundary vector against the current */
/*                 face, or else the loop terminated early because a */
/*                 vector with insufficient angular separation from the */
/*                 plane containing the face was found. */

		    if (ok) {

/*                    The current face is exterior. It's bounded by rays */
/*                    I and NEXT. */
			xidx = i__;
			found = TRUE_;
		    }

/*                 End of angular separation test block. */

		}

/*              End of non-zero cross product block. */

		if (! found) {

/*                 Look at the face bounded by the rays */
/*                 at indices I and NEXT+1. */

		    ++next;
		}
	    }

/*           End of NEXT loop. */

	    if (! found) {

/*              Look at the face bounded by the pairs of rays */
/*              including the ray at index I+1. */

		++i__;
	    }
	}

/*        End of I loop. */

    }

/*     End of search for exterior face using each pair of rays. */

/*     If we still haven't found an exterior face, we can't continue. */

    if (! found) {
	setmsg_("Unable to find face of convex hull of FOV of instrument #.", 
		(ftnlen)58);
	errch_("#", inst, (ftnlen)1, inst_len);
	sigerr_("SPICE(FACENOTFOUND)", (ftnlen)19);
	chkout_("ZZHULLAX", (ftnlen)8);
	return 0;
    }

/*     Arrival at this point means that the rays at indices */
/*     XIDX and NEXT define a plane such that all boundary */
/*     vectors lie in a half-space bounded by that plane. */

/*     We're now going to define a set of orthonormal basis vectors: */

/*        +X  points along the angle bisector of the bounding vectors */
/*            of the exterior face. */

/*        +Y  points along CP. */

/*        +Z  is the cross product of +X and +Y. */

/*     We'll call the reference frame having these basis vectors */
/*     the "face frame." */


    vhat_(&bounds[(i__1 = i__ * 3 - 3) < bounds_dim2 * 3 && 0 <= i__1 ? i__1 :
	     s_rnge("bounds", i__1, "zzhullax_", (ftnlen)683)], ray1);
    vhat_(&bounds[(i__1 = next * 3 - 3) < bounds_dim2 * 3 && 0 <= i__1 ? i__1 
	    : s_rnge("bounds", i__1, "zzhullax_", (ftnlen)684)], ray2);
    vlcom_(&c_b36, ray1, &c_b36, ray2, xvec);
    vhatip_(xvec);
    vhat_(cp, yvec);
    ucrss_(xvec, yvec, zvec);

/*     Create a transformation matrix to map the input boundary */
/*     vectors into the face frame. */

    for (i__ = 1; i__ <= 3; ++i__) {
	trans[(i__1 = i__ * 3 - 3) < 9 && 0 <= i__1 ? i__1 : s_rnge("trans", 
		i__1, "zzhullax_", (ftnlen)698)] = xvec[(i__2 = i__ - 1) < 3 
		&& 0 <= i__2 ? i__2 : s_rnge("xvec", i__2, "zzhullax_", (
		ftnlen)698)];
	trans[(i__1 = i__ * 3 - 2) < 9 && 0 <= i__1 ? i__1 : s_rnge("trans", 
		i__1, "zzhullax_", (ftnlen)699)] = yvec[(i__2 = i__ - 1) < 3 
		&& 0 <= i__2 ? i__2 : s_rnge("yvec", i__2, "zzhullax_", (
		ftnlen)699)];
	trans[(i__1 = i__ * 3 - 1) < 9 && 0 <= i__1 ? i__1 : s_rnge("trans", 
		i__1, "zzhullax_", (ftnlen)700)] = zvec[(i__2 = i__ - 1) < 3 
		&& 0 <= i__2 ? i__2 : s_rnge("zvec", i__2, "zzhullax_", (
		ftnlen)700)];
    }

/*     Now we're going to compute the longitude of each boundary in the */
/*     face frame. The vectors with indices XIDX and NEXT are excluded. */
/*     We expect all longitudes to be between MARGIN and pi - MARGIN. */

    minlon = pi_();
    maxlon = 0.;
    minix = 1;
    maxix = 1;
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	if (i__ != xidx && i__ != next) {

/*           The current vector is not a boundary of our edge, */
/*           so find its longitude. */

	    mxv_(trans, &bounds[(i__2 = i__ * 3 - 3) < bounds_dim2 * 3 && 0 <=
		     i__2 ? i__2 : s_rnge("bounds", i__2, "zzhullax_", (
		    ftnlen)720)], v);
	    reclat_(v, &r__, &lon, &lat);

/*           Update the longitude bounds. */

	    if (lon < minlon) {
		minix = i__;
		minlon = lon;
	    }
	    if (lon > maxlon) {
		maxix = i__;
		maxlon = lon;
	    }
	}
    }

/*     If the longitude bounds are not as expected, don't try */
/*     to continue. */

    if (minlon < 2e-12) {
	setmsg_("Minimum boundary vector longitude in exterior face frame is"
		" # radians. Minimum occurs at index #. This FOV does not con"
		"form to the requirements of this routine. Instrument is #.", (
		ftnlen)177);
	errdp_("#", &minlon, (ftnlen)1);
	errint_("#", &minix, (ftnlen)1);
	errch_("#", inst, (ftnlen)1, inst_len);
	sigerr_("SPICE(NOTSUPPORTED)", (ftnlen)19);
	chkout_("ZZHULLAX", (ftnlen)8);
	return 0;
    } else if (maxlon > pi_() - 2e-12) {
	setmsg_("Maximum boundary vector longitude in exterior face frame is"
		" # radians. Maximum occurs at index #. This FOV does not con"
		"form to the requirements of this routine. Instrument is #.", (
		ftnlen)177);
	errdp_("#", &maxlon, (ftnlen)1);
	errint_("#", &maxix, (ftnlen)1);
	errch_("#", inst, (ftnlen)1, inst_len);
	sigerr_("SPICE(FOVTOOWIDE)", (ftnlen)17);
	chkout_("ZZHULLAX", (ftnlen)8);
	return 0;
    }

/*     Let delta represent the amount we can rotate the exterior */
/*     face clockwise about +Z without contacting another boundary */
/*     vector. */

    delta = pi_() - maxlon;

/*     Rotate +Y by -DELTA/2 about +Z. The result is our candidate */
/*     FOV axis. Make the axis vector unit length. */

    d__1 = -delta / 2;
    vrotv_(yvec, zvec, &d__1, axis);
    vhatip_(axis);

/*     If we have a viable result, ALL boundary vectors have */
/*     angular separation less than HALFPI-MARGIN from AXIS. */

    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	sep = vsep_(&bounds[(i__2 = i__ * 3 - 3) < bounds_dim2 * 3 && 0 <= 
		i__2 ? i__2 : s_rnge("bounds", i__2, "zzhullax_", (ftnlen)794)
		], axis);
	if (sep > halfpi_() - 1e-12) {
	    setmsg_("Boundary vector at index # has angular separation of # "
		    "radians from candidate FOV axis. This FOV does not confo"
		    "rm to the requirements of this routine. Instrument is #.",
		     (ftnlen)167);
	    errint_("#", &i__, (ftnlen)1);
	    errdp_("#", &sep, (ftnlen)1);
	    errch_("#", inst, (ftnlen)1, inst_len);
	    sigerr_("SPICE(FOVTOOWIDE)", (ftnlen)17);
	    chkout_("ZZHULLAX", (ftnlen)8);
	    return 0;
	}
    }
    chkout_("ZZHULLAX", (ftnlen)8);
    return 0;
} /* zzhullax_ */