/* $Procedure ILLUM ( Illumination angles ) */
/* Subroutine */ int illum_(char *target, doublereal *et, char *abcorr, char *
obsrvr, doublereal *spoint, doublereal *phase, doublereal *solar,
doublereal *emissn, ftnlen target_len, ftnlen abcorr_len, ftnlen
obsrvr_len)
{
/* Initialized data */
static logical first = TRUE_;
extern /* Subroutine */ int zzbods2c_(integer *, char *, integer *,
logical *, char *, integer *, logical *, ftnlen, ftnlen);
extern doublereal vsep_(doublereal *, doublereal *);
extern /* Subroutine */ int vsub_(doublereal *, doublereal *, doublereal *
), vequ_(doublereal *, doublereal *), zzctruin_(integer *);
integer n;
doublereal radii[3];
extern /* Subroutine */ int chkin_(char *, ftnlen), errch_(char *, char *,
ftnlen, ftnlen);
logical found;
extern /* Subroutine */ int spkez_(integer *, doublereal *, char *, char *
, integer *, doublereal *, doublereal *, ftnlen, ftnlen);
extern logical eqstr_(char *, char *, ftnlen, ftnlen);
static logical svfnd1, svfnd2;
static integer svctr1[2], svctr2[2];
integer obscde;
doublereal lt;
extern /* Subroutine */ int bodvcd_(integer *, char *, integer *, integer
*, doublereal *, ftnlen);
integer frcode;
extern /* Subroutine */ int cidfrm_(integer *, integer *, char *, logical
*, ftnlen);
char frname[80];
integer trgcde;
doublereal offobs[3], obsvec[3], tepoch, normal[3];
static integer svtcde;
extern /* Subroutine */ int sigerr_(char *, ftnlen), chkout_(char *,
ftnlen);
static integer svobsc;
doublereal offsun[3];
extern /* Subroutine */ int setmsg_(char *, ftnlen);
doublereal sstate[6], sunvec[3], tstate[6];
static char svtarg[36];
extern /* Subroutine */ int surfnm_(doublereal *, doublereal *,
doublereal *, doublereal *, doublereal *);
extern logical return_(void);
static char svobsr[36];
extern /* Subroutine */ int vminus_(doublereal *, doublereal *);
doublereal lts;
/* $ Abstract */
/* Deprecated: This routine has been superseded by the SPICELIB */
/* routine ILUMIN. This routine is supported for purposes of */
/* backward compatibility only. */
/* Find the illumination angles at a specified surface point of a */
/* target 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 */
/* KERNEL */
/* NAIF_IDS */
/* SPK */
/* TIME */
/* $ Keywords */
/* GEOMETRY */
/* MOSPICE */
/* $ 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 */
/* -------- --- -------------------------------------------------- */
/* TARGET I Name of target body. */
/* ET I Epoch in ephemeris seconds past J2000. */
/* ABCORR I Desired aberration correction. */
/* OBSRVR I Name of observing body. */
/* SPOINT I Body-fixed coordinates of a target surface point. */
/* PHASE O Phase angle at the surface point. */
/* SOLAR O Solar incidence angle at the surface point. */
/* EMISSN O Emission angle at the surface point. */
/* $ Detailed_Input */
/* TARGET is the name of the target body. TARGET is */
/* case-insensitive, and leading and trailing blanks */
/* in TARGET are not significant. Optionally, you may */
/* supply a string containing the integer ID code for */
/* the object. For example both 'MOON' and '301' are */
/* legitimate strings that indicate the moon is the */
/* target body. */
/* ET is the epoch, specified in ephemeris seconds past */
/* J2000, at which the apparent illumination angles at */
/* the specified surface point on the target body, as */
/* seen from the observing body, are to be computed. */
/* ABCORR is the aberration correction to be used in */
/* computing the location and orientation of the */
/* target body and the location of the Sun. Possible */
/* values are: */
/* 'NONE' No aberration correction. */
/* 'LT' Correct the position and */
/* orientation of target body for */
/* light time, and correct the */
/* position of the Sun for light */
/* time. */
/* 'LT+S' Correct the observer-target vector */
/* for light time and stellar */
/* aberration, correct the */
/* orientation of the target body */
/* for light time, and correct the */
/* target-Sun vector for light time */
/* and stellar aberration. */
/* 'CN' Converged Newtonian light time */
/* correction. In solving the light */
/* time equation, the 'CN' */
/* correction iterates until the */
/* solution converges (three */
/* iterations on all supported */
/* platforms). Whether the 'CN+S' */
/* solution is substantially more */
/* accurate than the 'LT' solution */
/* depends on the geometry of the */
/* participating objects and on the */
/* accuracy of the input data. In */
/* all cases this routine will */
/* execute more slowly when a */
/* converged solution is computed. */
/* See the Particulars section of */
/* SPKEZR for a discussion of */
/* precision of light time */
/* corrections. */
/* Both the state and rotation of */
/* the target body are corrected for */
/* light time. */
/* 'CN+S' Converged Newtonian light time */
/* correction and stellar aberration */
/* correction. */
/* Both the state and rotation of */
/* the target body are corrected for */
/* light time. */
/* OBSRVR is the name of the observing body, typically a */
/* spacecraft, the earth, or a surface point on the */
/* earth. OBSRVR is case-insensitive, and leading */
/* and trailing blanks in OBSRVR are not significant. */
/* Optionally, you may supply a string containing the */
/* integer ID code for the object. For example both */
/* 'EARTH' and '399' are legitimate strings that */
/* indicate the earth is the observer. */
/* OBSRVR may be not be identical to TARGET. */
/* SPOINT is a surface point on the target body, expressed */
/* in rectangular body-fixed (body equator and prime */
/* meridian) coordinates. SPOINT need not be visible */
/* from the observer's location at time ET. */
/* $ Detailed_Output */
/* PHASE is the phase angle at SPOINT, as seen from OBSRVR */
/* at time ET. This is the angle between the */
/* SPOINT-OBSRVR vector and the SPOINT-Sun vector. */
/* Units are radians. The range of PHASE is [0, pi]. */
/* See Particulars below for a detailed discussion of */
/* the definition. */
/* SOLAR is the solar incidence angle at SPOINT, as seen */
/* from OBSRVR at time ET. This is the angle */
/* between the surface normal vector at SPOINT and the */
/* SPOINT-Sun vector. Units are radians. The range */
/* of SOLAR is [0, pi]. See Particulars below for a */
/* detailed discussion of the definition. */
/* EMISSN is the emission angle at SPOINT, as seen from */
/* OBSRVR at time ET. This is the angle between the */
/* surface normal vector at SPOINT and the */
/* SPOINT-observer vector. Units are radians. The */
/* range of EMISSN is [0, pi]. See Particulars below */
/* for a detailed discussion of the definition. */
/* $ Parameters */
/* None. */
/* $ Exceptions */
/* 1) If TARGET and OBSRVR are not distinct, the error */
/* SPICE(BODIESNOTDISTINCT) will be signaled. */
/* 2) If no SPK (ephemeris) data are available for the observer, */
/* target, and Sun at the time specified by ET, the error will */
/* be diagnosed by routines called by this routine. If light */
/* time corrections are used, SPK data for the target body must */
/* be available at the time ET - LT, where LT is the one-way */
/* light time from the target to the observer at ET. */
/* Additionally, SPK data must be available for the Sun at the */
/* time ET - LT - LT2, where LT2 is the light time from the Sun */
/* to the target body at time ET - LT. */
/* 3) If PCK data defining the orientation or shape of the target */
/* body are unavailable, the error will be diagnosed by routines */
/* called by this routine. */
/* 4) If no body-fixed frame is associated with the target body, */
/* the error SPICE(NOFRAME) is signaled. */
/* 5) If name of target or observer cannot be translated to its */
/* NAIF ID code, the error SPICE(IDCODENOTFOUND) is signaled. */
/* $ Files */
/* No files are input to this routine. However, ILLUM expects */
/* that the appropriate SPK and PCK files have been loaded via */
/* FURNSH. */
/* $ Particulars */
/* The term "illumination angles" refers to following set of */
/* angles: */
/* solar incidence angle Angle between the surface normal at */
/* the specified surface point and the */
/* vector from the surface point to the */
/* Sun. */
/* emission angle Angle between the surface normal at */
/* the specified surface point and the */
/* vector from the surface point to the */
/* observer. */
/* phase angle Angle between the vectors from the */
/* surface point to the observing body's */
/* location and from the surface point */
/* to the Sun. */
/* The diagram below illustrates the geometrical relationships */
/* defining these angles. The labels for the solar incidence, */
/* emission, and phase angles are "s.i.", "e.", and "phase". */
/* * */
/* Sun */
/* surface normal vector */
/* ._ _. */
/* |\ /| Sun vector */
/* \ phase / */
/* \ . . / */
/* . . */
/* \ ___ / */
/* . \/ \/ */
/* _\ s.i./ */
/* . / \ / */
/* . | e. \ / */
/* * <--------------- * surface point on */
/* viewing vector target body */
/* location to viewing */
/* (observer) location */
/* Note that if the target-observer vector, the target normal vector */
/* at the surface point, and the target-sun vector are coplanar, */
/* then phase is the sum of incidence and emission. This is rarely */
/* true; usually */
/* phase angle < solar incidence angle + emission angle */
/* All of the above angles can be computed using light time */
/* corrections, light time and stellar aberration corrections, or */
/* no aberration corrections. The way aberration corrections */
/* are used is described below. */
/* Care must be used in computing light time corrections. The */
/* guiding principle used here is "describe what appears in */
/* an image." We ignore differential light time; the light times */
/* from all points on the target to the observer are presumed to be */
/* equal. */
/* Observer-target body vector */
/* --------------------------- */
/* Let ET be the epoch at which an observation or remote */
/* sensing measurement is made, and let ET - LT ("LT" stands */
/* for "light time") be the epoch at which the photons received */
/* at ET were emitted from the body (we use the term "emitted" */
/* loosely here). */
/* The correct observer-target vector points from the observer's */
/* location at ET to the target body's location at ET - LT. */
/* The target-observer vector points in the opposite direction. */
/* Since light time corrections are not symmetric, the correct */
/* target-observer vector CANNOT be found by computing the light */
/* time corrected position of the observer as seen from the */
/* target body. */
/* Target body's orientation */
/* ------------------------- */
/* Using the definitions of ET and LT above, the target */
/* body's orientation at ET - LT is used. The surface */
/* normal is dependent on the target body's orientation, so */
/* the body's orientation model must be evaluated for the correct */
/* epoch. */
/* Target body -- Sun vector */
/* ------------------------- */
/* All surface features on the target body will appear in */
/* a measurement made at ET as they were at ET-LT. In */
/* particular, lighting on the target body is dependent on */
/* the apparent location of the Sun as seen from the target */
/* body at ET-LT. So, a second light time correction is used */
/* in finding the apparent location of the Sun. */
/* Stellar aberration corrections, when used, are applied as follows: */
/* Observer-target body vector */
/* --------------------------- */
/* In addition to light time correction, stellar aberration is */
/* used in computing the apparent target body position as seen */
/* from the observer's location at time ET. This apparent */
/* position defines the observer-target body vector. */
/* Target body-Sun vector */
/* ---------------------- */
/* The target body-Sun vector is the apparent position of the Sun, */
/* corrected for light time and stellar aberration, as seen from */
/* the target body at time ET-LT. Note that the target body's */
/* position is not affected by the stellar aberration correction */
/* applied in finding its apparent position as seen by the */
/* observer. */
/* Once all of the vectors, as well as the target body's */
/* orientation, have been computed with the proper aberration */
/* corrections, the element of time is eliminated from the */
/* computation. The problem becomes a purely geometrical one, */
/* and is described by the diagram above. */
/* $ Examples */
/* The numerical results shown for this example 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. */
/* In the following example program, the file */
/* spk_m_031103-040201_030502.bsp */
/* is a binary SPK file containing data for Mars Global Surveyor, */
/* Mars, and the Sun for a time interval bracketing the date */
/* 2004 JAN 1 12:00:00 UTC. */
/* pck00007.tpc is a planetary constants kernel file containing */
/* radii and rotation model constants. naif0007.tls is a */
/* leapseconds kernel. */
/* Find the phase, solar incidence, and emission angles at the */
/* sub-solar and sub-spacecraft points on Mars as seen from the */
/* Mars Global Surveyor spacecraft at a specified UTC time. */
/* Use light time and stellar aberration corrections. */
/* PROGRAM ANGLES */
/* IMPLICIT NONE */
/* C */
/* C SPICELIB functions */
/* C */
/* DOUBLE PRECISION DPR */
/* C */
/* C Local parameters */
/* C */
/* INTEGER NAMLEN */
/* PARAMETER ( NAMLEN = 32 ) */
/* INTEGER TIMLEN */
/* PARAMETER ( TIMLEN = 25 ) */
/* C */
/* C Local variables */
/* C */
/* CHARACTER*(NAMLEN) OBSRVR */
/* CHARACTER*(NAMLEN) TARGET */
/* CHARACTER*(TIMLEN) UTC */
/* DOUBLE PRECISION ALT */
/* DOUBLE PRECISION ET */
/* DOUBLE PRECISION SSCEMI */
/* DOUBLE PRECISION SSCPHS */
/* DOUBLE PRECISION SSCSOL */
/* DOUBLE PRECISION SSLEMI */
/* DOUBLE PRECISION SSLPHS */
/* DOUBLE PRECISION SSLSOL */
/* DOUBLE PRECISION SSOLPT ( 3 ) */
/* DOUBLE PRECISION SSCPT ( 3 ) */
/* C */
/* C Load kernel files. */
/* C */
/* CALL FURNSH ( 'naif0007.tls' ) */
/* CALL FURNSH ( 'pck00007.tpc' ) */
/* CALL FURNSH ( 'spk_m_031103-040201_030502.bsp' ) */
/* C */
/* C Convert our UTC time to ephemeris seconds past J2000. */
/* C */
/* UTC = '2004 JAN 1 12:00:00' */
/* CALL UTC2ET ( UTC, ET ) */
/* C */
/* C Assign observer and target names. The acronym MGS */
/* C indicates Mars Global Surveyor. See NAIF_IDS for a */
/* C list of names recognized by SPICE. */
/* C */
/* TARGET = 'Mars' */
/* OBSRVR = 'MGS' */
/* C */
/* C Find the sub-solar point on the Earth as seen from */
/* C the MGS spacecraft at ET. Use the "surface intercept" */
/* C style of sub-point definition. This makes it easy */
/* C to verify the solar incidence angle. */
/* C */
/* CALL SUBSOL ( 'Near point', TARGET, ET, */
/* . 'LT+S', OBSRVR, SSOLPT ) */
/* C */
/* C Now find the sub-spacecraft point. Use the */
/* C "nearest point" definition of the sub-point */
/* C here---this makes it easy to verify the emission angle. */
/* C */
/* CALL SUBPT ( 'Near point', TARGET, ET, */
/* . 'LT+S', OBSRVR, SSCPT, ALT ) */
/* C */
/* C Find the phase, solar incidence, and emission */
/* C angles at the sub-solar point on the Earth as seen */
/* C from Mars Observer at time ET. */
/* C */
/* CALL ILLUM ( TARGET, ET, 'LT+S', OBSRVR, */
/* . SSOLPT, SSLPHS, SSLSOL, SSLEMI ) */
/* C */
/* C Do the same for the sub-spacecraft point. */
/* C */
/* CALL ILLUM ( TARGET, ET, 'LT+S', OBSRVR, */
/* . SSCPT, SSCPHS, SSCSOL, SSCEMI ) */
/* C */
/* C Convert the angles to degrees and write them out. */
/* C */
/* SSLPHS = DPR() * SSLPHS */
/* SSLSOL = DPR() * SSLSOL */
/* SSLEMI = DPR() * SSLEMI */
/* SSCPHS = DPR() * SSCPHS */
/* SSCSOL = DPR() * SSCSOL */
/* SSCEMI = DPR() * SSCEMI */
/* WRITE (*,*) ' ' */
/* WRITE (*,*) 'UTC epoch is ', UTC */
/* WRITE (*,*) ' ' */
/* WRITE (*,*) 'Illumination angles at the sub-solar point:' */
/* WRITE (*,*) ' ' */
/* WRITE (*,*) 'Phase angle (deg.): ', SSLPHS */
/* WRITE (*,*) 'Solar incidence angle (deg.): ', SSLSOL */
/* WRITE (*,*) 'Emission angle (deg.): ', SSLEMI */
/* WRITE (*,*) ' ' */
/* WRITE (*,*) 'The solar incidence angle should be 0.' */
/* WRITE (*,*) 'The emission and phase angles should be equal.' */
/* WRITE (*,*) ' ' */
/* WRITE (*,*) 'Illumination angles at the sub-s/c point:' */
/* WRITE (*,*) ' ' */
/* WRITE (*,*) 'Phase angle (deg.): ', SSCPHS */
/* WRITE (*,*) 'Solar incidence angle (deg.): ', SSCSOL */
/* WRITE (*,*) 'Emission angle (deg.): ', SSCEMI */
/* WRITE (*,*) ' ' */
/* WRITE (*,*) 'The emission angle should be 0.' */
/* WRITE (*,*) 'The solar incidence and phase angles should '// */
/* . 'be equal.' */
/* END */
/* When this program is executed, the output will be: */
/* UTC epoch is 2004 JAN 1 12:00:00 */
/* Illumination angles at the sub-solar point: */
/* Phase angle (deg.): 150.210714 */
/* Solar incidence angle (deg.): 6.3735213E-15 */
/* Emission angle (deg.): 150.210714 */
/* The solar incidence angle should be 0. */
/* The emission and phase angles should be equal. */
/* Illumination angles at the sub-s/c point: */
/* Phase angle (deg.): 123.398202 */
/* Solar incidence angle (deg.): 123.398202 */
/* Emission angle (deg.): 6.36110936E-15 */
/* The emission angle should be 0. */
/* The solar incidence and phase angles should be equal. */
/* $ Restrictions */
/* None. */
/* $ Literature_References */
/* None. */
/* $ Author_and_Institution */
/* C.H. Acton (JPL) */
/* B.V. Semenov (JPL) */
/* N.J. Bachman (JPL) */
/* $ Version */
/* - SPICELIB Version 1.3.0, 04-JUL-2014 (NJB) (BVS) */
/* Discussion of light time corrections was updated. Assertions */
/* that converged light time corrections are unlikely to be */
/* useful were removed. */
/* Last update was 19-SEP-2013 (BVS) */
/* Updated to save the input body names and ZZBODTRN state */
/* counters and to do name-ID conversions only if the counters */
/* have changed. */
/* - SPICELIB Version 1.2.2, 18-MAY-2010 (BVS) */
/* Index lines now state that this routine is deprecated. */
/* - SPICELIB Version 1.2.1, 07-FEB-2008 (NJB) */
/* Abstract now states that this routine is deprecated. */
/* - SPICELIB Version 1.2.0, 23-OCT-2005 (NJB) */
/* Updated to remove non-standard use of duplicate arguments */
/* in VSUB calls. Replaced call to BODVAR with call to BODVCD. */
/* - SPICELIB Version 1.1.0, 22-JUL-2004 (NJB) */
/* Updated to support representations of integers in the input */
/* arguments TARGET and OBSRVR. */
/* - SPICELIB Version 1.0.2, 27-JUL-2003 (NJB) (CHA) */
/* Various header corrections were made. The example program */
/* was upgraded to use real kernels, and the program's output is */
/* shown. */
/* - SPICELIB Version 1.0.1, 10-JUL-2002 (NJB) */
/* Updated Index_Entries header section. */
/* - SPICELIB Version 1.0.0, 21-MAR-1999 (NJB) */
/* Adapted from the MGSSPICE version dated 10-MAR-1992. */
/* -& */
/* $ Index_Entries */
/* DEPRECATED illumination angles */
/* DEPRECATED lighting angles */
/* DEPRECATED phase angle */
/* DEPRECATED solar incidence angle */
/* DEPRECATED emission angle */
/* -& */
/* $ Revisions */
/* - SPICELIB Version 1.2.0, 23-OCT-2005 (NJB) */
/* Updated to remove non-standard use of duplicate arguments */
/* in VSUB calls. Replaced call to BODVAR with call to BODVCD. */
/* - SPICELIB Version 1.1.0, 22-JUL-2004 (NJB) */
/* Updated to support representations of integers in the */
/* input arguments TARGET and OBSRVR: calls to BODN2C */
/* were replaced by calls to BODS2C. */
/* -& */
/* SPICELIB functions */
/* Local parameters */
/* Saved body name length. */
/* Local variables */
/* Saved name/ID item declarations. */
/* Saved name/ID items. */
/* Initial values. */
/* Standard SPICE error handling. */
if (return_()) {
return 0;
} else {
chkin_("ILLUM", (ftnlen)5);
}
/* Initialization. */
if (first) {
/* Initialize counters. */
zzctruin_(svctr1);
zzctruin_(svctr2);
first = FALSE_;
}
/* Obtain integer codes for the target and observer. */
zzbods2c_(svctr1, svtarg, &svtcde, &svfnd1, target, &trgcde, &found, (
ftnlen)36, target_len);
if (! found) {
setmsg_("The target, '#', is not a recognized name for an ephemeris "
"object. The cause of this problem may be that you need an up"
"dated version of the SPICE Toolkit. ", (ftnlen)155);
errch_("#", target, (ftnlen)1, target_len);
sigerr_("SPICE(IDCODENOTFOUND)", (ftnlen)21);
chkout_("ILLUM", (ftnlen)5);
return 0;
}
zzbods2c_(svctr2, svobsr, &svobsc, &svfnd2, obsrvr, &obscde, &found, (
ftnlen)36, obsrvr_len);
if (! found) {
setmsg_("The observer, '#', is not a recognized name for an ephemeri"
"s object. The cause of this problem may be that you need an "
"updated version of the SPICE Toolkit. ", (ftnlen)157);
errch_("#", obsrvr, (ftnlen)1, obsrvr_len);
sigerr_("SPICE(IDCODENOTFOUND)", (ftnlen)21);
chkout_("ILLUM", (ftnlen)5);
return 0;
}
/* The observer and target must be distinct. */
if (trgcde == obscde) {
setmsg_("Target is #; observer is #.", (ftnlen)27);
errch_("#", target, (ftnlen)1, target_len);
errch_("#", obsrvr, (ftnlen)1, obsrvr_len);
sigerr_("SPICE(BODIESNOTDISTINCT)", (ftnlen)24);
chkout_("ILLUM", (ftnlen)5);
return 0;
}
/* Find the name of the body-fixed frame associated with the */
/* target body. We'll want the state of the target relative to */
/* the observer in this body-fixed frame. */
cidfrm_(&trgcde, &frcode, frname, &found, (ftnlen)80);
if (! found) {
setmsg_("No body-fixed frame is associated with target body #; a fra"
"me kernel must be loaded to make this association. Consult "
"the FRAMES Required Reading for details.", (ftnlen)159);
errch_("#", target, (ftnlen)1, target_len);
sigerr_("SPICE(NOFRAME)", (ftnlen)14);
chkout_("ILLUM", (ftnlen)5);
return 0;
}
/* Find the body-fixed state of the target as seen from the observer */
/* at ET. The appropriate aberration corrections will be used in */
/* evaluating this state. */
spkez_(&trgcde, et, frname, abcorr, &obscde, tstate, <, (ftnlen)80,
abcorr_len);
/* Determine the epoch to be used in computing the target-Sun vector. */
if (eqstr_(abcorr, "NONE", abcorr_len, (ftnlen)4)) {
tepoch = *et;
} else {
tepoch = *et - lt;
}
/* Find the body-fixed state of the Sun as seen from the target at */
/* TEPOCH. */
spkez_(&c__10, &tepoch, frname, abcorr, &trgcde, sstate, <s, (ftnlen)80,
abcorr_len);
/* Grab the position portions of the states (the first three */
/* elements of each state). Negate the observer-target vector, */
/* since the vector required for the illumination angle */
/* computation is the target-observer vector. The vectors we've */
/* found point from the target body center to the observer and */
/* Sun, and already take light time corrections into account. */
vminus_(tstate, obsvec);
vequ_(sstate, sunvec);
/* Now we'll modify target-observer and target-Sun vectors to */
/* take into account the offset between the target center and the */
/* surface point of interest; we want the vectors to point from */
/* the surface point to the observer and Sun respectively. */
vsub_(obsvec, spoint, offobs);
vsub_(sunvec, spoint, offsun);
/* Find the surface normal at SPOINT. We'll need the radii of the */
/* target body. */
bodvcd_(&trgcde, "RADII", &c__3, &n, radii, (ftnlen)5);
surfnm_(radii, &radii[1], &radii[2], spoint, normal);
/* Find the illumination angles. VSEP will give us angular */
/* separation in radians. */
*phase = vsep_(offsun, offobs);
*solar = vsep_(normal, offsun);
*emissn = vsep_(normal, offobs);
chkout_("ILLUM", (ftnlen)5);
return 0;
} /* illum_ */
/* $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_ */
/* $Procedure ZZEDTERM ( Ellipsoid terminator ) */
/* Subroutine */ int zzedterm_(char *type__, doublereal *a, doublereal *b,
doublereal *c__, doublereal *srcrad, doublereal *srcpos, integer *
npts, doublereal *trmpts, ftnlen type_len)
{
/* System generated locals */
integer trmpts_dim2, i__1, i__2;
doublereal d__1, d__2, d__3;
/* Builtin functions */
integer s_cmp(char *, char *, ftnlen, ftnlen);
double asin(doublereal);
integer s_rnge(char *, integer, char *, integer);
double d_sign(doublereal *, doublereal *);
/* Local variables */
extern /* Subroutine */ int vadd_(doublereal *, doublereal *, doublereal *
);
doublereal rmin, rmax;
extern /* Subroutine */ int vscl_(doublereal *, doublereal *, doublereal *
);
extern doublereal vdot_(doublereal *, doublereal *), vsep_(doublereal *,
doublereal *);
integer nitr;
extern /* Subroutine */ int vsub_(doublereal *, doublereal *, doublereal *
), vequ_(doublereal *, doublereal *);
doublereal d__, e[3];
integer i__;
doublereal s, angle, v[3], x[3], delta, y[3], z__[3], inang;
extern /* Subroutine */ int chkin_(char *, ftnlen), frame_(doublereal *,
doublereal *, doublereal *);
doublereal plane[4];
extern /* Subroutine */ int ucase_(char *, char *, ftnlen, ftnlen),
errch_(char *, char *, ftnlen, ftnlen), vpack_(doublereal *,
doublereal *, doublereal *, doublereal *);
doublereal theta;
extern /* Subroutine */ int errdp_(char *, doublereal *, ftnlen);
doublereal trans[9] /* was [3][3] */, srcpt[3], vtemp[3];
extern doublereal vnorm_(doublereal *), twopi_(void);
extern /* Subroutine */ int ljust_(char *, char *, ftnlen, ftnlen),
pl2nvc_(doublereal *, doublereal *, doublereal *);
doublereal lambda;
extern /* Subroutine */ int nvp2pl_(doublereal *, doublereal *,
doublereal *);
extern doublereal halfpi_(void);
doublereal minang, minrad, maxang, maxrad;
extern /* Subroutine */ int latrec_(doublereal *, doublereal *,
doublereal *, doublereal *);
doublereal angerr;
logical umbral;
extern doublereal touchd_(doublereal *);
doublereal offset[3], prvdif;
extern /* Subroutine */ int sigerr_(char *, ftnlen);
doublereal outang, plcons, prvang;
extern /* Subroutine */ int chkout_(char *, ftnlen), setmsg_(char *,
ftnlen), errint_(char *, integer *, ftnlen);
char loctyp[50];
extern logical return_(void);
extern /* Subroutine */ int vminus_(doublereal *, doublereal *);
doublereal dir[3];
extern /* Subroutine */ int mxv_(doublereal *, doublereal *, doublereal *)
;
doublereal vtx[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. */
/* Compute a set of points on the umbral or penumbral terminator of */
/* a specified ellipsoid, given a spherical light source. */
/* $ 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 */
/* ELLIPSES */
/* $ Keywords */
/* BODY */
/* GEOMETRY */
/* MATH */
/* $ Declarations */
/* $ Brief_I/O */
/* Variable I/O Description */
/* -------- --- -------------------------------------------------- */
/* TYPE I Terminator type. */
/* A I Length of ellipsoid semi-axis lying on the x-axis. */
/* B I Length of ellipsoid semi-axis lying on the y-axis. */
/* C I Length of ellipsoid semi-axis lying on the z-axis. */
/* SRCRAD I Radius of light source. */
/* SRCPOS I Position of center of light source. */
/* NPTS I Number of points in terminator point set. */
/* TRMPTS O Terminator point set. */
/* $ Detailed_Input */
/* TYPE is a string indicating the type of terminator to */
/* compute: umbral or penumbral. The umbral */
/* terminator is the boundary of the portion of the */
/* ellipsoid surface in total shadow. The penumbral */
/* terminator is the boundary of the portion of the */
/* surface that is completely illuminated. Possible */
/* values of TYPE are */
/* 'UMBRAL' */
/* 'PENUMBRAL' */
/* Case and leading or trailing blanks in TYPE are */
/* not significant. */
/* A, */
/* B, */
/* C are the lengths of the semi-axes of a triaxial */
/* ellipsoid. The ellipsoid is centered at the */
/* origin and oriented so that its axes lie on the */
/* x, y and z axes. A, B, and C are the lengths of */
/* the semi-axes that point in the x, y, and z */
/* directions respectively. */
/* Length units associated with A, B, and C must */
/* match those associated with SRCRAD, SRCPOS, */
/* and the output TRMPTS. */
/* SRCRAD is the radius of the spherical light source. */
/* SRCPOS is the position of the center of the light source */
/* relative to the center of the ellipsoid. */
/* NPTS is the number of terminator points to compute. */
/* $ Detailed_Output */
/* TRMPTS is an array of points on the umbral or penumbral */
/* terminator of the ellipsoid, as specified by the */
/* input argument TYPE. The Ith point is contained */
/* in the array elements */
/* TRMPTS(J,I), J = 1, 2, 3 */
/* The terminator points are expressed in the */
/* body-fixed reference frame associated with the */
/* ellipsoid. Units are those associated with */
/* the input axis lengths. */
/* Each terminator point is the point of tangency of */
/* a plane that is also tangent to the light source. */
/* These associated points of tangency on the light */
/* source have uniform distribution in longitude when */
/* expressed in a cylindrical coordinate system whose */
/* Z-axis is SRCPOS. The magnitude of the separation */
/* in longitude between these tangency points on the */
/* light source is */
/* 2*Pi / NPTS */
/* If the target is spherical, the terminator points */
/* also are uniformly distributed in longitude in the */
/* cylindrical system described above. If the target */
/* is non-spherical, the longitude distribution of */
/* the points generally is not uniform. */
/* $ Parameters */
/* None. */
/* $ Exceptions */
/* 1) If the terminator type is not recognized, the error */
/* SPICE(NOTSUPPORTED) is signaled. */
/* 2) If the set size NPTS is not at least 1, the error */
/* SPICE(INVALIDSIZE) is signaled. */
/* 3) If any of the ellipsoid's semi-axis lengths is non-positive, */
/* the error SPICE(INVALIDAXISLENGTH) is signaled. */
/* 4) If the light source has non-positive radius, the error */
/* SPICE(INVALIDRADIUS) is signaled. */
/* 5) If the light source intersects the smallest sphere */
/* centered at the origin and containing the ellipsoid, the */
/* error SPICE(OBJECTSTOOCLOSE) is signaled. */
/* $ Files */
/* None. */
/* $ Particulars */
/* This routine models the boundaries of shadow regions on an */
/* ellipsoid "illuminated" by a spherical light source. Light rays */
/* are assumed to travel along straight lines; refraction is not */
/* modeled. */
/* Points on the ellipsoid at which the entire cap of the light */
/* source is visible are considered to be completely illuminated. */
/* Points on the ellipsoid at which some portion (or all) of the cap */
/* of the light source are blocked are considered to be in partial */
/* (or total) shadow. */
/* In this routine, we use the term "umbral terminator" to denote */
/* the curve ususally called the "terminator": this curve is the */
/* boundary of the portion of the surface that lies in total shadow. */
/* We use the term "penumbral terminator" to denote the boundary of */
/* the completely illuminated portion of the surface. */
/* In general, the terminator on an ellipsoid is a more complicated */
/* curve than the limb (which is always an ellipse). Aside from */
/* various special cases, the terminator does not lie in a plane. */
/* However, the condition for a point X on the ellipsoid to lie on */
/* the terminator is simple: a plane tangent to the ellipsoid at X */
/* must also be tangent to the light source. If this tangent plane */
/* does not intersect the vector from the center of the ellipsoid to */
/* the center of the light source, then X lies on the umbral */
/* terminator; otherwise X lies on the penumbral terminator. */
/* $ Examples */
/* See the SPICELIB routine EDTERM. */
/* $ Restrictions */
/* This is a private SPICELIB routine. User applications should not */
/* call this routine. */
/* $ Literature_References */
/* None. */
/* $ Author_and_Institution */
/* N.J. Bachman (JPL) */
/* $ Version */
/* - SPICELIB Version 1.0.0, 03-FEB-2007 (NJB) */
/* -& */
/* $ Index_Entries */
/* find terminator on ellipsoid */
/* find umbral terminator on ellipsoid */
/* find penumbral terminator on ellipsoid */
/* -& */
/* SPICELIB functions */
/* Local parameters */
/* Local variables */
/* Standard SPICELIB error handling. */
/* Parameter adjustments */
trmpts_dim2 = *npts;
/* Function Body */
if (return_()) {
return 0;
}
chkin_("ZZEDTERM", (ftnlen)8);
/* Check the terminator type. */
ljust_(type__, loctyp, type_len, (ftnlen)50);
ucase_(loctyp, loctyp, (ftnlen)50, (ftnlen)50);
if (s_cmp(loctyp, "UMBRAL", (ftnlen)50, (ftnlen)6) == 0) {
umbral = TRUE_;
} else if (s_cmp(loctyp, "PENUMBRAL", (ftnlen)50, (ftnlen)9) == 0) {
umbral = FALSE_;
} else {
setmsg_("Terminator type must be UMBRAL or PENUMBRAL but was actuall"
"y #.", (ftnlen)63);
errch_("#", type__, (ftnlen)1, type_len);
sigerr_("SPICE(NOTSUPPORTED)", (ftnlen)19);
chkout_("ZZEDTERM", (ftnlen)8);
return 0;
}
/* Check the terminator set dimension. */
if (*npts < 1) {
setmsg_("Set must contain at least one point; NPTS = #.", (ftnlen)47)
;
errint_("#", npts, (ftnlen)1);
sigerr_("SPICE(INVALIDSIZE)", (ftnlen)18);
chkout_("ZZEDTERM", (ftnlen)8);
return 0;
}
/* The ellipsoid semi-axes must have positive length. */
if (*a <= 0. || *b <= 0. || *c__ <= 0.) {
setmsg_("Semi-axis lengths: A = #, B = #, C = #. ", (ftnlen)41);
errdp_("#", a, (ftnlen)1);
errdp_("#", b, (ftnlen)1);
errdp_("#", c__, (ftnlen)1);
sigerr_("SPICE(INVALIDAXISLENGTH)", (ftnlen)24);
chkout_("ZZEDTERM", (ftnlen)8);
return 0;
}
/* Check the input light source radius. */
if (*srcrad <= 0.) {
setmsg_("Light source must have positive radius; actual radius was #."
, (ftnlen)60);
errdp_("#", srcrad, (ftnlen)1);
sigerr_("SPICE(INVALIDRADIUS)", (ftnlen)20);
chkout_("ZZEDTERM", (ftnlen)8);
return 0;
}
/* The light source must not intersect the outer bounding */
/* sphere of the ellipsoid. */
d__ = vnorm_(srcpos);
/* Computing MAX */
d__1 = max(*a,*b);
rmax = max(d__1,*c__);
/* Computing MIN */
d__1 = min(*a,*b);
rmin = min(d__1,*c__);
if (*srcrad + rmax >= d__) {
/* The light source is too close. */
setmsg_("Light source intersects outer bounding sphere of the ellips"
"oid. Light source radius = #; ellipsoid's longest axis = #;"
" sum = #; distance between centers = #.", (ftnlen)158);
errdp_("#", srcrad, (ftnlen)1);
errdp_("#", &rmax, (ftnlen)1);
d__1 = *srcrad + rmax;
errdp_("#", &d__1, (ftnlen)1);
errdp_("#", &d__, (ftnlen)1);
sigerr_("SPICE(OBJECTSTOOCLOSE)", (ftnlen)22);
chkout_("ZZEDTERM", (ftnlen)8);
return 0;
}
/* Find bounds on the angular size of the target as seen */
/* from the source. */
/* Computing MIN */
d__1 = rmax / d__;
minang = asin((min(d__1,1.)));
/* Computing MIN */
d__1 = rmin / d__;
maxang = asin((min(d__1,1.)));
/* Let the inverse of the ellipsoid-light source vector be the */
/* Z-axis of a frame we'll use to generate the terminator set. */
vminus_(srcpos, z__);
frame_(z__, x, y);
/* Create the rotation matrix required to convert vectors */
/* from the source-centered frame back to the target body-fixed */
/* frame. */
vequ_(x, trans);
vequ_(y, &trans[3]);
vequ_(z__, &trans[6]);
/* Find the maximum and minimum target radii. */
/* Computing MAX */
d__1 = max(*a,*b);
maxrad = max(d__1,*c__);
/* Computing MIN */
d__1 = min(*a,*b);
minrad = min(d__1,*c__);
if (umbral) {
/* Compute the angular offsets from the axis of rays tangent to */
/* both the source and the bounding spheres of the target, where */
/* the tangency points lie in a half-plane bounded by the line */
/* containing the origin and SRCPOS. (We'll call this line */
/* the "axis.") */
/* OUTANG corresponds to the target's outer bounding sphere; */
/* INANG to the inner bounding sphere. */
outang = asin((*srcrad - maxrad) / d__);
inang = asin((*srcrad - minrad) / d__);
} else {
/* Compute the angular offsets from the axis of rays tangent to */
/* both the source and the bounding spheres of the target, where */
/* the tangency points lie in opposite half-planes bounded by the */
/* axis (compare the case above). */
/* OUTANG corresponds to the target's outer bounding sphere; */
/* INANG to the inner bounding sphere. */
outang = asin((*srcrad + maxrad) / d__);
inang = asin((*srcrad + minrad) / d__);
}
/* Compute the angular delta we'll use for generating */
/* terminator points. */
delta = twopi_() / *npts;
/* Generate the terminator points. */
i__1 = *npts;
for (i__ = 1; i__ <= i__1; ++i__) {
theta = (i__ - 1) * delta;
/* Let SRCPT be the surface point on the source lying in */
/* the X-Y plane of the frame produced by FRAME */
/* and corresponding to the angle THETA. */
latrec_(srcrad, &theta, &c_b30, srcpt);
/* Now solve for the angle by which SRCPT must be rotated (toward */
/* +Z in the umbral case, away from +Z in the penumbral case) */
/* so that a plane tangent to the source at SRCPT is also tangent */
/* to the target. The rotation is bracketed by OUTANG on the low */
/* side and INANG on the high side in the umbral case; the */
/* bracketing values are reversed in the penumbral case. */
if (umbral) {
angle = outang;
} else {
angle = inang;
}
prvdif = twopi_();
prvang = angle + halfpi_();
nitr = 0;
for(;;) { /* while(complicated condition) */
d__2 = (d__1 = angle - prvang, abs(d__1));
if (!(nitr <= 10 && touchd_(&d__2) < prvdif))
break;
++nitr;
d__2 = (d__1 = angle - prvang, abs(d__1));
prvdif = touchd_(&d__2);
prvang = angle;
/* Find the closest point on the ellipsoid to the plane */
/* corresponding to "ANGLE". */
/* The tangent point on the source is obtained by rotating */
/* SRCPT by ANGLE towards +Z. The plane's normal vector is */
/* parallel to VTX in the source-centered frame. */
latrec_(srcrad, &theta, &angle, vtx);
vequ_(vtx, dir);
/* VTX and DIR are expressed in the source-centered frame. We */
/* must translate VTX to the target frame and rotate both */
/* vectors into that frame. */
mxv_(trans, vtx, vtemp);
vadd_(srcpos, vtemp, vtx);
mxv_(trans, dir, vtemp);
vequ_(vtemp, dir);
/* Create the plane defined by VTX and DIR. */
nvp2pl_(dir, vtx, plane);
/* Find the closest point on the ellipsoid to the plane. At */
/* the point we seek, the outward normal on the ellipsoid is */
/* parallel to the choice of plane normal that points away */
/* from the origin. We can always obtain this choice from */
/* PL2NVC. */
pl2nvc_(plane, dir, &plcons);
/* At the point */
/* E = (x, y, z) */
/* on the ellipsoid's surface, an outward normal */
/* is */
/* N = ( x/A**2, y/B**2, z/C**2 ) */
/* which is also */
/* lambda * ( DIR(1), DIR(2), DIR(3) ) */
/* Equating components in the normal vectors yields */
/* E = lambda * ( DIR(1)*A**2, DIR(2)*B**2, DIR(3)*C**2 ) */
/* Taking the inner product with the point E itself and */
/* applying the ellipsoid equation, we find */
/* lambda * <DIR, E> = < N, E > = 1 */
/* The first term above is */
/* lambda**2 * || ( A*DIR(1), B*DIR(2), C*DIR(3) ) ||**2 */
/* So the positive root lambda is */
/* 1 / || ( A*DIR(1), B*DIR(2), C*DIR(3) ) || */
/* Having lambda we can compute E. */
d__1 = *a * dir[0];
d__2 = *b * dir[1];
d__3 = *c__ * dir[2];
vpack_(&d__1, &d__2, &d__3, v);
lambda = 1. / vnorm_(v);
d__1 = *a * v[0];
d__2 = *b * v[1];
d__3 = *c__ * v[2];
vpack_(&d__1, &d__2, &d__3, e);
vscl_(&lambda, e, &trmpts[(i__2 = i__ * 3 - 3) < trmpts_dim2 * 3
&& 0 <= i__2 ? i__2 : s_rnge("trmpts", i__2, "zzedterm_",
(ftnlen)586)]);
/* Make a new estimate of the plane rotation required to touch */
/* the target. */
vsub_(&trmpts[(i__2 = i__ * 3 - 3) < trmpts_dim2 * 3 && 0 <= i__2
? i__2 : s_rnge("trmpts", i__2, "zzedterm_", (ftnlen)592)]
, vtx, offset);
/* Let ANGERR be an estimate of the magnitude of angular error */
/* between the plane and the terminator. */
angerr = vsep_(dir, offset) - halfpi_();
/* Let S indicate the sign of the altitude error: where */
/* S is positive, the plane is above E. */
d__1 = vdot_(e, dir);
s = d_sign(&c_b35, &d__1);
if (umbral) {
/* If the plane is above the target, increase the */
/* rotation angle; otherwise decrease the angle. */
angle += s * angerr;
} else {
/* This is the penumbral case; decreasing the angle */
/* "lowers" the plane toward the target. */
angle -= s * angerr;
}
}
}
chkout_("ZZEDTERM", (ftnlen)8);
return 0;
} /* zzedterm_ */
/* $Procedure SPKE15 ( Evaluate a type 15 SPK data record) */
/* Subroutine */ int spke15_(doublereal *et, doublereal *recin, doublereal *
state)
{
/* System generated locals */
doublereal d__1;
/* Builtin functions */
double sqrt(doublereal), d_mod(doublereal *, doublereal *), d_sign(
doublereal *, doublereal *);
/* Local variables */
doublereal near__, dmdt;
extern /* Subroutine */ int vscl_(doublereal *, doublereal *, doublereal *
);
extern doublereal vdot_(doublereal *, doublereal *), vsep_(doublereal *,
doublereal *);
extern /* Subroutine */ int vequ_(doublereal *, doublereal *);
integer j2flg;
doublereal p, angle, dnode, z__;
extern /* Subroutine */ int chkin_(char *, ftnlen);
doublereal epoch, speed, dperi, theta, manom;
extern /* Subroutine */ int moved_(doublereal *, integer *, doublereal *),
errdp_(char *, doublereal *, ftnlen), vcrss_(doublereal *,
doublereal *, doublereal *);
extern doublereal twopi_(void);
extern logical vzero_(doublereal *);
extern /* Subroutine */ int vrotv_(doublereal *, doublereal *, doublereal
*, doublereal *);
doublereal oneme2, state0[6];
extern /* Subroutine */ int prop2b_(doublereal *, doublereal *,
doublereal *, doublereal *);
doublereal pa[3], gm, ta, dt;
extern doublereal pi_(void);
doublereal tp[3], pv[3], cosinc;
extern /* Subroutine */ int sigerr_(char *, ftnlen), vhatip_(doublereal *)
, chkout_(char *, ftnlen), vsclip_(doublereal *, doublereal *),
setmsg_(char *, ftnlen);
doublereal tmpsta[6], oj2;
extern logical return_(void);
doublereal ecc;
extern doublereal dpr_(void);
doublereal dot, rpl, k2pi;
/* $ Abstract */
/* Evaluates a single SPK data record from a segment of type 15 */
/* (Precessing Conic Propagation). */
/* $ 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 */
/* SPK */
/* $ Keywords */
/* EPHEMERIS */
/* $ Declarations */
/* $ Brief_I/O */
/* Variable I/O Description */
/* -------- --- -------------------------------------------------- */
/* ET I Target epoch. */
/* RECIN I Data record. */
/* STATE O State (position and velocity). */
/* $ Detailed_Input */
/* ET is a target epoch, specified as ephemeris seconds past */
/* J2000, at which a state vector is to be computed. */
/* RECIN is a data record which, when evaluated at epoch ET, */
/* will give the state (position and velocity) of some */
/* body, relative to some center, in some inertial */
/* reference frame. */
/* The structure of RECIN is: */
/* RECIN(1) epoch of periapsis */
/* in ephemeris seconds past J2000. */
/* RECIN(2)-RECIN(4) unit trajectory pole vector */
/* RECIN(5)-RECIN(7) unit periapsis vector */
/* RECIN(8) semi-latus rectum---p in the */
/* equation: */
/* r = p/(1 + ECC*COS(Nu)) */
/* RECIN(9) eccentricity */
/* RECIN(10) J2 processing flag describing */
/* what J2 corrections are to be */
/* applied when the orbit is */
/* propagated. */
/* All J2 corrections are applied */
/* if this flag has a value that */
/* is not 1,2 or 3. */
/* If the value of the flag is 3 */
/* no corrections are done. */
/* If the value of the flag is 1 */
/* no corrections are computed for */
/* the precession of the line */
/* of apsides. However, regression */
/* of the line of nodes is */
/* performed. */
/* If the value of the flag is 2 */
/* no corrections are done for */
/* the regression of the line of */
/* nodes. However, precession of the */
/* line of apsides is performed. */
/* Note that J2 effects are computed */
/* only if the orbit is elliptic and */
/* does not intersect the central */
/* body. */
/* RECIN(11)-RECIN(13) unit central body pole vector */
/* RECIN(14) central body GM */
/* RECIN(15) central body J2 */
/* RECIN(16) central body radius */
/* Units are radians, km, seconds */
/* $ Detailed_Output */
/* STATE is the state produced by evaluating RECIN at ET. */
/* Units are km and km/sec. */
/* $ Parameters */
/* None. */
/* $ Files */
/* None. */
/* $ Exceptions */
/* 1) If the eccentricity is less than zero, the error */
/* 'SPICE(BADECCENTRICITY)' will be signalled. */
/* 2) If the semi-latus rectum is non-positive, the error */
/* 'SPICE(BADLATUSRECTUM)' is signalled. */
/* 3) If the pole vector, trajectory pole vector or periapsis vector */
/* has zero length, the error 'SPICE(BADVECTOR)' is signalled. */
/* 4) If the trajectory pole vector and the periapsis vector are */
/* not orthogonal, the error 'SPICE(BADINITSTATE)' is */
/* signalled. The test for orthogonality is very crude. The */
/* routine simply checks that the absolute value of the dot */
/* product of the unit vectors parallel to the trajectory pole */
/* and periapse vectors is less than 0.00001. This check is */
/* intended to catch blunders, not to enforce orthogonality to */
/* double precision tolerance. */
/* 5) If the mass of the central body is non-positive, the error */
/* 'SPICE(NONPOSITIVEMASS)' is signalled. */
/* 6) If the radius of the central body is negative, the error */
/* 'SPICE(BADRADIUS)' is signalled. */
/* $ Particulars */
/* This algorithm applies J2 corrections for precessing the */
/* node and argument of periapse for an object orbiting an */
/* oblate spheroid. */
/* Note the effects of J2 are incorporated only for elliptic */
/* orbits that do not intersect the central body. */
/* While the derivation of the effect of the various harmonics */
/* of gravitational field are beyond the scope of this header */
/* the effect of the J2 term of the gravity model are as follows */
/* The line of node precesses. Over one orbit average rate of */
/* precession, DNode/dNu, is given by */
/* 3 J2 */
/* dNode/dNu = - ----------------- DCOS( inc ) */
/* 2 (P/RPL)**2 */
/* (Since this is always less than zero for oblate spheroids, this */
/* should be called regression of nodes.) */
/* The line of apsides precesses. The average rate of precession */
/* DPeri/dNu is given by */
/* 3 J2 */
/* dPeri/dNu = ----------------- ( 5*DCOS ( inc ) - 1 ) */
/* 2 (P/RPL)**2 */
/* Details of these formulae are given in the Battin's book (see */
/* literature references below). */
/* It is assumed that this routine is used in conjunction with */
/* the routine SPKR15 as shown here: */
/* CALL SPKR15 ( HANDLE, DESCR, ET, RECIN ) */
/* CALL SPKE15 ( ET, RECIN, STATE ) */
/* where it is known in advance that the HANDLE, DESCR pair points */
/* to a type 15 data segment. */
/* $ Examples */
/* The SPKEnn routines are almost always used in conjunction with */
/* the corresponding SPKRnn routines, which read the records from */
/* SPK files. */
/* The data returned by the SPKRnn routine is in its rawest form, */
/* taken directly from the segment. As such, it will be meaningless */
/* to a user unless he/she understands the structure of the data type */
/* completely. Given that understanding, however, the SPKRnn */
/* routines might be used to examine raw segment data before */
/* evaluating it with the SPKEnn routines. */
/* C */
/* C Get a segment applicable to a specified body and epoch. */
/* C */
/* CALL SPKSFS ( BODY, ET, HANDLE, DESCR, IDENT, FOUND ) */
/* C */
/* C Look at parts of the descriptor. */
/* C */
/* CALL DAFUS ( DESCR, 2, 6, DCD, ICD ) */
/* CENTER = ICD( 2 ) */
/* REF = ICD( 3 ) */
/* TYPE = ICD( 4 ) */
/* IF ( TYPE .EQ. 15 ) THEN */
/* CALL SPKR15 ( HANDLE, DESCR, ET, RECORD ) */
/* . */
/* . Look at the RECORD data. */
/* . */
/* CALL SPKE15 ( ET, RECORD, STATE ) */
/* . */
/* . Check out the evaluated state. */
/* . */
/* END IF */
/* $ Restrictions */
/* None. */
/* $ Author_and_Institution */
/* K.R. Gehringer (JPL) */
/* S. Schlaifer (JPL) */
/* W.L. Taber (JPL) */
/* $ Literature_References */
/* [1] `Fundamentals of Celestial Mechanics', Second Edition 1989 */
/* by J.M.A. Danby; Willman-Bell, Inc., P.O. Box 35025 */
/* Richmond Virginia; pp 345-347. */
/* [2] `Astronautical Guidance', by Richard H. Battin. 1964 */
/* McGraw-Hill Book Company, San Francisco. pp 199 */
/* $ Version */
/* - SPICELIB Version 1.2.0, 02-SEP-2005 (NJB) */
/* Updated to remove non-standard use of duplicate arguments */
/* in VHAT, VROTV, and VSCL calls. */
/* - SPICELIB Version 1.1.0, 29-FEB-1996 (KRG) */
/* The declaration for the SPICELIB function PI is now */
/* preceded by an EXTERNAL statement declaring PI to be an */
/* external function. This removes a conflict with any */
/* compilers that have a PI intrinsic function. */
/* - SPICELIB Version 1.0.0, 15-NOV-1994 (WLT) (SS) */
/* -& */
/* $ Index_Entries */
/* evaluate type_15 spk segment */
/* -& */
/* $ Revisions */
/* - SPICELIB Version 1.2.0, 02-SEP-2005 (NJB) */
/* Updated to remove non-standard use of duplicate arguments */
/* in VHAT, VROTV, and VSCL calls. */
/* - SPICELIB Version 1.1.0, 29-FEB-1996 (KRG) */
/* The declaration for the SPICELIB function PI is now */
/* preceded by an EXTERNAL statement declaring PI to be an */
/* external function. This removes a conflict with any */
/* compilers that have a PI intrinsic function. */
/* - SPICELIB Version 1.0.0, 15-NOV-1994 (WLT) (SS) */
/* -& */
/* SPICELIB Functions */
/* Local Variables */
/* Standard SPICE error handling. */
if (return_()) {
return 0;
}
chkin_("SPKE15", (ftnlen)6);
/* Fetch the various entities from the input record, first the epoch. */
epoch = recin[0];
/* The trajectory pole vector. */
vequ_(&recin[1], tp);
/* The periapsis vector. */
vequ_(&recin[4], pa);
/* Semi-latus rectum ( P in the P/(1 + ECC*COS(Nu) ), */
/* and eccentricity. */
p = recin[7];
ecc = recin[8];
/* J2 processing flag. */
j2flg = (integer) recin[9];
/* Central body pole vector. */
vequ_(&recin[10], pv);
/* The central mass, J2 and radius of the central body. */
gm = recin[13];
oj2 = recin[14];
rpl = recin[15];
/* Check all the inputs here for obvious failures. Yes, perhaps */
/* this is overkill. However, there is a lot more computation */
/* going on in this routine so that the small amount of overhead */
/* here should not be significant. */
if (p <= 0.) {
setmsg_("The semi-latus rectum supplied to the SPK type 15 evaluator"
" was non-positive. This value must be positive. The value s"
"upplied was #.", (ftnlen)133);
errdp_("#", &p, (ftnlen)1);
sigerr_("SPICE(BADLATUSRECTUM)", (ftnlen)21);
chkout_("SPKE15", (ftnlen)6);
return 0;
} else if (ecc < 0.) {
setmsg_("The eccentricity supplied for a type 15 segment is negative"
". It must be non-negative. The value supplied to the type 1"
"5 evaluator was #. ", (ftnlen)138);
errdp_("#", &ecc, (ftnlen)1);
sigerr_("SPICE(BADECCENTRICITY)", (ftnlen)22);
chkout_("SPKE15", (ftnlen)6);
return 0;
} else if (gm <= 0.) {
setmsg_("The mass supplied for the central body of a type 15 segment"
" was non-positive. Masses must be positive. The value suppl"
"ied was #. ", (ftnlen)130);
errdp_("#", &gm, (ftnlen)1);
sigerr_("SPICE(NONPOSITIVEMASS)", (ftnlen)22);
chkout_("SPKE15", (ftnlen)6);
return 0;
} else if (vzero_(tp)) {
setmsg_("The trajectory pole vector supplied to SPKE15 had length ze"
"ro. The most likely cause of this problem is a corrupted SPK"
" (ephemeris) file. ", (ftnlen)138);
sigerr_("SPICE(BADVECTOR)", (ftnlen)16);
chkout_("SPKE15", (ftnlen)6);
return 0;
} else if (vzero_(pa)) {
setmsg_("The periapse vector supplied to SPKE15 had length zero. The"
" most likely cause of this problem is a corrupted SPK (ephem"
"eris) file. ", (ftnlen)131);
sigerr_("SPICE(BADVECTOR)", (ftnlen)16);
chkout_("SPKE15", (ftnlen)6);
return 0;
} else if (vzero_(pv)) {
setmsg_("The central pole vector supplied to SPKE15 had length zero."
" The most likely cause of this problem is a corrupted SPK (e"
"phemeris) file. ", (ftnlen)135);
sigerr_("SPICE(BADVECTOR)", (ftnlen)16);
chkout_("SPKE15", (ftnlen)6);
return 0;
} else if (rpl < 0.) {
setmsg_("The central body radius was negative. It must be zero or po"
"sitive. The value supplied was #. ", (ftnlen)94);
errdp_("#", &rpl, (ftnlen)1);
sigerr_("SPICE(BADRADIUS)", (ftnlen)16);
chkout_("SPKE15", (ftnlen)6);
return 0;
}
/* Convert TP, PV and PA to unit vectors. */
/* (It won't hurt to polish them up a bit here if they are already */
/* unit vectors.) */
vhatip_(pa);
vhatip_(tp);
vhatip_(pv);
/* One final check. Make sure the pole and periapse vectors are */
/* orthogonal. (We will use a very crude check but this should */
/* rule out any obvious errors.) */
dot = vdot_(pa, tp);
if (abs(dot) > 1e-5) {
angle = vsep_(pa, tp) * dpr_();
setmsg_("The periapsis and trajectory pole vectors are not orthogona"
"l. The anglebetween them is # degrees. ", (ftnlen)98);
errdp_("#", &angle, (ftnlen)1);
sigerr_("SPICE(BADINITSTATE)", (ftnlen)19);
chkout_("SPKE15", (ftnlen)6);
return 0;
}
/* Compute the distance and speed at periapse. */
near__ = p / (ecc + 1.);
speed = sqrt(gm / p) * (ecc + 1.);
/* Next get the position at periapse ... */
vscl_(&near__, pa, state0);
/* ... and the velocity at periapsis. */
vcrss_(tp, pa, &state0[3]);
vsclip_(&speed, &state0[3]);
/* Determine the elapsed time from periapse to the requested */
/* epoch and propagate the state at periapsis to the epoch of */
/* interest. */
/* Note that we are making use of the following fact. */
/* If R is a rotation, then the states obtained by */
/* the following blocks of code are mathematically the */
/* same. (In reality they may differ slightly due to */
/* roundoff.) */
/* Code block 1. */
/* CALL MXV ( R, STATE0, STATE0 ) */
/* CALL MXV ( R, STATE0(4), STATE0(4) ) */
/* CALL PROP2B( GM, STATE0, DT, STATE ) */
/* Code block 2. */
/* CALL PROP2B( GM, STATE0, DT, STATE ) */
/* CALL MXV ( R, STATE, STATE ) */
/* CALL MXV ( R, STATE(4), STATE(4) ) */
/* This allows us to first compute the propagation of our initial */
/* state and then if needed perform the precession of the line */
/* of nodes and apsides by simply precessing the resulting state. */
dt = *et - epoch;
prop2b_(&gm, state0, &dt, state);
/* If called for, handle precession needed due to the J2 term. Note */
/* that the motion of the lines of nodes and apsides is formulated */
/* in terms of the true anomaly. This means we need the accumulated */
/* true anomaly in order to properly transform the state. */
if (j2flg != 3 && oj2 != 0. && ecc < 1. && near__ > rpl) {
/* First compute the change in mean anomaly since periapsis. */
/* Computing 2nd power */
d__1 = ecc;
oneme2 = 1. - d__1 * d__1;
dmdt = oneme2 / p * sqrt(gm * oneme2 / p);
manom = dmdt * dt;
/* Next compute the angle THETA such that THETA is between */
/* -pi and pi and such than MANOM = THETA + K*2*pi for */
/* some integer K. */
d__1 = twopi_();
theta = d_mod(&manom, &d__1);
if (abs(theta) > pi_()) {
d__1 = twopi_();
theta -= d_sign(&d__1, &theta);
}
k2pi = manom - theta;
/* We can get the accumulated true anomaly from the propagated */
/* state theta and the accumulated mean anomaly prior to this */
/* orbit. */
ta = vsep_(pa, state);
ta = d_sign(&ta, &theta);
ta += k2pi;
/* Determine how far the line of nodes and periapsis have moved. */
cosinc = vdot_(pv, tp);
/* Computing 2nd power */
d__1 = rpl / p;
z__ = ta * 1.5 * oj2 * (d__1 * d__1);
dnode = -z__ * cosinc;
/* Computing 2nd power */
d__1 = cosinc;
dperi = z__ * (d__1 * d__1 * 2.5 - .5);
/* Precess the periapsis by rotating the state vector about the */
/* trajectory pole */
if (j2flg != 1) {
vrotv_(state, tp, &dperi, tmpsta);
vrotv_(&state[3], tp, &dperi, &tmpsta[3]);
moved_(tmpsta, &c__6, state);
}
/* Regress the line of nodes by rotating the state */
/* about the pole of the central body. */
if (j2flg != 2) {
vrotv_(state, pv, &dnode, tmpsta);
vrotv_(&state[3], pv, &dnode, &tmpsta[3]);
moved_(tmpsta, &c__6, state);
}
/* We could perform the rotations above in the other order, */
/* but we would also have to rotate the pole before precessing */
/* the line of apsides. */
}
/* That's all folks. Check out and return. */
chkout_("SPKE15", (ftnlen)6);
return 0;
} /* spke15_ */
/* $Procedure ZZFOVAXI ( Generate an axis vector for polygonal FOV ) */
/* Subroutine */ int zzfovaxi_(char *inst, integer *n, doublereal *bounds,
doublereal *axis, ftnlen inst_len)
{
/* System generated locals */
integer bounds_dim2, i__1, i__2, i__3;
doublereal d__1;
/* Builtin functions */
integer s_rnge(char *, integer, char *, integer);
/* Local variables */
extern /* Subroutine */ int vadd_(doublereal *, doublereal *, doublereal *
);
doublereal uvec[3];
extern /* Subroutine */ int vhat_(doublereal *, doublereal *);
extern doublereal vsep_(doublereal *, doublereal *);
integer next;
extern /* Subroutine */ int vequ_(doublereal *, doublereal *), zzhullax_(
char *, integer *, doublereal *, doublereal *, ftnlen);
integer i__;
doublereal v[3];
extern /* Subroutine */ int chkin_(char *, ftnlen), errch_(char *, char *,
ftnlen, ftnlen);
doublereal limit;
extern /* Subroutine */ int vcrss_(doublereal *, doublereal *, doublereal
*);
extern logical vzero_(doublereal *);
doublereal cp[3];
extern logical failed_(void);
logical ok;
extern /* Subroutine */ int cleard_(integer *, doublereal *);
extern doublereal halfpi_(void);
extern /* Subroutine */ int sigerr_(char *, ftnlen), vhatip_(doublereal *)
, chkout_(char *, ftnlen), vsclip_(doublereal *, doublereal *),
setmsg_(char *, ftnlen), errint_(char *, integer *, ftnlen);
extern logical return_(void);
doublereal sep;
/* $ 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. */
/* Generate an axis of an instrument's polygonal FOV such that all */
/* of the FOV's boundary vectors have angular separation of strictly */
/* less than pi/2 radians from this axis. */
/* $ 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 first computes the average of the unitized input */
/* boundary vectors; if this vector satisfies the angular separation */
/* constraint (1) in Detailed_Input, a unit length copy of this */
/* vector is returned as the FOV axis. */
/* If the procedure above fails, an algorithm based on selection */
/* of a suitable face of the boundary vector's convex hull is tried. */
/* See the routine ZZHULLAX for details. */
/* If the second approach fails, an error is signaled. */
/* 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 ZZHULLAX */
/* is called after the simple approach fails. */
/* $ Examples */
/* See SPICELIB private routine ZZGFFVIN. */
/* $ Restrictions */
/* 1) This is a SPICE private routine. User applications should not */
/* call this routine. */
/* 2) There may "reasonable" polygonal FOVs that cannot be handled */
/* by this routine. See the discussions in Detailed_Input, */
/* Exceptions, and Particulars above for restrictions on the */
/* input set of FOV boundary vectors. */
/* $ Literature_References */
/* None. */
/* $ Author_and_Institution */
/* N.J. Bachman (JPL) */
/* $ Version */
/* - SPICELIB Version 1.0.0, 05-MAR-2009 (NJB) */
/* -& */
/* SPICELIB functions */
/* Local parameters */
/* Local variables */
/* Parameter adjustments */
bounds_dim2 = *n;
/* Function Body */
if (return_()) {
return 0;
}
chkin_("ZZFOVAXI", (ftnlen)8);
/* 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_("ZZFOVAXI", (ftnlen)8);
return 0;
}
/* Check for linearly dependent consecutive boundary vectors. */
i__1 = *n;
for (i__ = 1; i__ <= i__1; ++i__) {
/* 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 is exterior. */
vcrss_(&bounds[(i__2 = i__ * 3 - 3) < bounds_dim2 * 3 && 0 <= i__2 ?
i__2 : s_rnge("bounds", i__2, "zzfovaxi_", (ftnlen)313)], &
bounds[(i__3 = next * 3 - 3) < bounds_dim2 * 3 && 0 <= i__3 ?
i__3 : s_rnge("bounds", i__3, "zzfovaxi_", (ftnlen)313)], 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_("ZZFOVAXI", (ftnlen)8);
return 0;
}
}
/* First try the average of the FOV unit boundary vectors as */
/* a candidate axis. In many cases, this simple approach */
/* does the trick. */
cleard_(&c__3, axis);
i__1 = *n;
for (i__ = 1; i__ <= i__1; ++i__) {
vhat_(&bounds[(i__2 = i__ * 3 - 3) < bounds_dim2 * 3 && 0 <= i__2 ?
i__2 : s_rnge("bounds", i__2, "zzfovaxi_", (ftnlen)346)],
uvec);
vadd_(uvec, axis, v);
vequ_(v, axis);
}
d__1 = 1. / *n;
vsclip_(&d__1, axis);
/* If each boundary vector has sufficiently small */
/* angular separation from AXIS, we're done. */
limit = halfpi_() - 1e-12;
ok = TRUE_;
i__ = 1;
while(i__ <= *n && ok) {
sep = vsep_(&bounds[(i__1 = i__ * 3 - 3) < bounds_dim2 * 3 && 0 <=
i__1 ? i__1 : s_rnge("bounds", i__1, "zzfovaxi_", (ftnlen)365)
], axis);
if (sep > limit) {
ok = FALSE_;
} else {
++i__;
}
}
if (! ok) {
/* See whether we can find an axis using a */
/* method based on finding a face of the convex */
/* hull of the FOV. ZZHULLAX signals an error */
/* if it doesn't succeed. */
zzhullax_(inst, n, bounds, axis, inst_len);
if (failed_()) {
chkout_("ZZFOVAXI", (ftnlen)8);
return 0;
}
}
/* At this point AXIS is valid. Make the axis vector unit length. */
vhatip_(axis);
chkout_("ZZFOVAXI", (ftnlen)8);
return 0;
} /* zzfovaxi_ */
/* $Procedure SPKW15 ( SPK, write a type 15 segment ) */
/* Subroutine */ int spkw15_(integer *handle, integer *body, integer *center,
char *frame, doublereal *first, doublereal *last, char *segid,
doublereal *epoch, doublereal *tp, doublereal *pa, doublereal *p,
doublereal *ecc, doublereal *j2flg, doublereal *pv, doublereal *gm,
doublereal *j2, doublereal *radius, ftnlen frame_len, ftnlen
segid_len)
{
/* System generated locals */
integer i__1;
/* Local variables */
extern /* Subroutine */ int vhat_(doublereal *, doublereal *);
doublereal mypa[3];
extern doublereal vdot_(doublereal *, doublereal *), vsep_(doublereal *,
doublereal *);
extern /* Subroutine */ int vequ_(doublereal *, doublereal *);
doublereal mytp[3];
integer i__;
doublereal angle;
extern /* Subroutine */ int chkin_(char *, ftnlen);
doublereal descr[5];
integer value;
extern /* Subroutine */ int errdp_(char *, doublereal *, ftnlen);
extern logical vzero_(doublereal *);
extern /* Subroutine */ int dafada_(doublereal *, integer *), dafbna_(
integer *, doublereal *, char *, ftnlen), dafena_(void);
extern logical failed_(void);
doublereal record[16];
extern integer lastnb_(char *, ftnlen);
extern /* Subroutine */ int sigerr_(char *, ftnlen), chkout_(char *,
ftnlen), setmsg_(char *, ftnlen), errint_(char *, integer *,
ftnlen), spkpds_(integer *, integer *, char *, integer *,
doublereal *, doublereal *, doublereal *, ftnlen);
extern logical return_(void);
extern doublereal dpr_(void);
doublereal dot;
/* $ Abstract */
/* Write an SPK segment of type 15 given a type 15 data record. */
/* $ 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 */
/* SPK */
/* $ Keywords */
/* EPHEMERIS */
/* $ Declarations */
/* $ Brief_I/O */
/* Variable I/O Description */
/* -------- --- -------------------------------------------------- */
/* HANDLE I Handle of an SPK file open for writing. */
/* BODY I Body code for ephemeris object. */
/* CENTER I Body code for the center of motion of the body. */
/* FRAME I The reference frame of the states. */
/* FIRST I First valid time for which states can be computed. */
/* LAST I Last valid time for which states can be computed. */
/* SEGID I Segment identifier. */
/* EPOCH I Epoch of the periapse. */
/* TP I Trajectory pole vector. */
/* PA I Periapsis vector. */
/* P I Semi-latus rectum. */
/* ECC I Eccentricity. */
/* J2FLG I J2 processing flag. */
/* PV I Central body pole vector. */
/* GM I Central body GM. */
/* J2 I Central body J2. */
/* RADIUS I Equatorial radius of central body. */
/* $ Detailed_Input */
/* HANDLE is the file handle of an SPK file that has been */
/* opened for writing. */
/* BODY is the NAIF ID for the body whose states are */
/* to be recorded in an SPK file. */
/* CENTER is the NAIF ID for the center of motion associated */
/* with BODY. */
/* FRAME is the reference frame that states are referenced to, */
/* for example 'J2000'. */
/* FIRST are the bounds on the ephemeris times, expressed as */
/* LAST seconds past J2000. */
/* SEGID is the segment identifier. An SPK segment identifier */
/* may contain up to 40 characters. */
/* EPOCH is the epoch of the orbit elements at periapse */
/* in ephemeris seconds past J2000. */
/* TP is a vector parallel to the angular momentum vector */
/* of the orbit at epoch expressed relative to FRAME. A */
/* unit vector parallel to TP will be stored in the */
/* output segment. */
/* PA is a vector parallel to the position vector of the */
/* trajectory at periapsis of EPOCH expressed relative */
/* to FRAME. A unit vector parallel to PA will be */
/* stored in the output segment. */
/* P is the semi-latus rectum--- p in the equation: */
/* r = p/(1 + ECC*COS(Nu)) */
/* ECC is the eccentricity. */
/* J2FLG is the J2 processing flag describing what J2 */
/* corrections are to be applied when the orbit is */
/* propagated. */
/* All J2 corrections are applied if the value of J2FLG */
/* is not 1, 2 or 3. */
/* If the value of the flag is 3 no corrections are */
/* done. */
/* If the value of the flag is 1 no corrections are */
/* computed for the precession of the line of apsides. */
/* However, regression of the line of nodes is */
/* performed. */
/* If the value of the flag is 2 no corrections are */
/* done for the regression of the line of nodes. */
/* However, precession of the line of apsides is */
/* performed. */
/* Note that J2 effects are computed only if the orbit */
/* is elliptic and does not intersect the central body. */
/* PV is a vector parallel to the north pole vector of the */
/* central body expressed relative to FRAME. A unit */
/* vector parallel to PV will be stored in the output */
/* segment. */
/* GM is the central body GM. */
/* J2 is the central body J2 (dimensionless). */
/* RADIUS is the equatorial radius of the central body. */
/* Units are radians, km, seconds. */
/* $ Detailed_Output */
/* None. A type 15 segment is written to the file attached */
/* to HANDLE. */
/* $ Parameters */
/* None. */
/* $ Exceptions */
/* 1) If the eccentricity is less than zero, the error */
/* 'SPICE(BADECCENTRICITY)' will be signaled. */
/* 2) If the semi-latus rectum is 0, the error */
/* 'SPICE(BADLATUSRECTUM)' is signaled. */
/* 3) If the pole vector, trajectory pole vector or periapsis vector */
/* have zero length, the error 'SPICE(BADVECTOR)' is signaled. */
/* 4) If the trajectory pole vector and the periapsis vector are */
/* not orthogonal, the error 'SPICE(BADINITSTATE)' is signaled. */
/* The test for orthogonality is very crude. The routine simply */
/* checks that the dot product of the unit vectors parallel */
/* to the trajectory pole and periapse vectors is less than */
/* 0.00001. This check is intended to catch blunders, not to */
/* enforce orthogonality to double precision capacity. */
/* 5) If the mass of the central body is non-positive, the error */
/* 'SPICE(NONPOSITIVEMASS)' is signaled. */
/* 6) If the radius of the central body is negative, the error */
/* 'SPICE(BADRADIUS)' is signaled. */
/* 7) If the segment identifier has more than 40 non-blank characters */
/* the error 'SPICE(SEGIDTOOLONG)' is signaled. */
/* 8) If the segment identifier contains non-printing characters */
/* the error 'SPICE(NONPRINTABLECHARS)' is signaled. */
/* 9) If there are inconsistencies in the BODY, CENTER, FRAME or */
/* FIRST and LAST times, the problem will be diagnosed by */
/* a routine in the call tree of this routine. */
/* $ Files */
/* A new type 15 SPK segment is written to the SPK file attached */
/* to HANDLE. */
/* $ Particulars */
/* This routine writes an SPK type 15 data segment to the open SPK */
/* file according to the format described in the type 15 section of */
/* the SPK Required Reading. The SPK file must have been opened with */
/* write access. */
/* This routine is provided to provide direct support for the MASL */
/* precessing orbit formulation. */
/* $ Examples */
/* Suppose that at time EPOCH you have the J2000 periapsis */
/* state of some object relative to some central body and would */
/* like to create a type 15 SPK segment to model the motion of */
/* the object using simple regression and precession of the */
/* line of nodes and apsides. The following code fragment */
/* illustrates how you can prepare such a segment. We shall */
/* assume that you have in hand the J2000 direction of the */
/* central body's pole vector, its GM, J2 and equatorial */
/* radius. In addition we assume that you have opened an SPK */
/* file for write access and that it is attached to HANDLE. */
/* (If your state is at an epoch other than periapse the */
/* fragment below will NOT produce a "correct" type 15 segment */
/* for modeling the motion of your object.) */
/* C */
/* C First we get the osculating elements. */
/* C */
/* CALL OSCELT ( STATE, EPOCH, GM, ELTS ) */
/* C */
/* C From these collect the eccentricity and semi-latus rectum. */
/* C */
/* ECC = ELTS ( 2 ) */
/* P = ELTS ( 1 ) * ( 1.0D0 + ECC ) */
/* C */
/* C Next get the trajectory pole vector and the */
/* C periapsis vector. */
/* C */
/* CALL UCRSS ( STATE(1), STATE(4), TP ) */
/* CALL VHAT ( STATE(1), PA ) */
/* C */
/* C Enable both J2 corrections. */
/* C */
/* J2FLG = 0.0D0 */
/* C */
/* C Now add the segment. */
/* C */
/* CALL SPKW15 ( HANDLE, BODY, CENTER, FRAME, FIRST, LAST, */
/* . SEGID, EPOCH, TP, PA, P, ECC, */
/* . J2FLG, PV, GM, J2, RADIUS ) */
/* $ Restrictions */
/* None. */
/* $ Literature_References */
/* None. */
/* $ Author_and_Institution */
/* N.J. Bachman (JPL) */
/* W.L. Taber (JPL) */
/* $ Version */
/* - SPICELIB Version 2.0.0, 29-MAY-2012 (NJB) */
/* Input vectors that nominally have unit length */
/* are mapped to local copies that actually do */
/* have unit length. The applicable inputs are TP, PA, */
/* and PV. The Detailed Input header section was updated */
/* to reflect the change. */
/* Some typos in error messages were corrected. */
/* - SPICELIB Version 1.0.0, 28-NOV-1994 (WLT) */
/* -& */
/* $ Index_Entries */
/* Write a type 15 spk segment */
/* -& */
/* SPICELIB Functions */
/* Local Variables */
/* Segment descriptor size */
/* Segment identifier size */
/* SPK data type */
/* Range of printing characters */
/* Number of items in a segment */
/* Standard SPICE error handling. */
if (return_()) {
return 0;
}
chkin_("SPKW15", (ftnlen)6);
/* Fetch the various entities from the inputs and put them into */
/* the data record, first the epoch. */
record[0] = *epoch;
/* Convert TP and PA to unit vectors. */
vhat_(pa, mypa);
vhat_(tp, mytp);
/* The trajectory pole vector. */
vequ_(mytp, &record[1]);
/* The periapsis vector. */
vequ_(mypa, &record[4]);
/* Semi-latus rectum ( P in the P/(1 + ECC*COS(Nu) ), */
/* and eccentricity. */
record[7] = *p;
record[8] = *ecc;
/* J2 processing flag. */
record[9] = *j2flg;
/* Central body pole vector. */
vhat_(pv, &record[10]);
/* The central mass, J2 and radius of the central body. */
record[13] = *gm;
record[14] = *j2;
record[15] = *radius;
/* Check all the inputs here for obvious failures. It's much */
/* better to check them now and quit than it is to get a bogus */
/* segment into an SPK file and diagnose it later. */
if (*p <= 0.) {
setmsg_("The semi-latus rectum supplied to the SPK type 15 evaluator"
" was non-positive. This value must be positive. The value s"
"upplied was #.", (ftnlen)133);
errdp_("#", p, (ftnlen)1);
sigerr_("SPICE(BADLATUSRECTUM)", (ftnlen)21);
chkout_("SPKW15", (ftnlen)6);
return 0;
} else if (*ecc < 0.) {
setmsg_("The eccentricity supplied for a type 15 segment is negative"
". It must be non-negative. The value supplied to the type 1"
"5 evaluator was #. ", (ftnlen)138);
errdp_("#", ecc, (ftnlen)1);
sigerr_("SPICE(BADECCENTRICITY)", (ftnlen)22);
chkout_("SPKW15", (ftnlen)6);
return 0;
} else if (*gm <= 0.) {
setmsg_("The mass supplied for the central body of a type 15 segment"
" was non-positive. Masses must be positive. The value suppl"
"ied was #. ", (ftnlen)130);
errdp_("#", gm, (ftnlen)1);
sigerr_("SPICE(NONPOSITIVEMASS)", (ftnlen)22);
chkout_("SPKW15", (ftnlen)6);
return 0;
} else if (vzero_(tp)) {
setmsg_("The trajectory pole vector supplied to SPKW15 had length ze"
"ro. The most likely cause of this problem is an uninitialize"
"d vector.", (ftnlen)128);
sigerr_("SPICE(BADVECTOR)", (ftnlen)16);
chkout_("SPKW15", (ftnlen)6);
return 0;
} else if (vzero_(pa)) {
setmsg_("The periapse vector supplied to SPKW15 had length zero. The"
" most likely cause of this problem is an uninitialized vecto"
"r.", (ftnlen)121);
sigerr_("SPICE(BADVECTOR)", (ftnlen)16);
chkout_("SPKW15", (ftnlen)6);
return 0;
} else if (vzero_(pv)) {
setmsg_("The central pole vector supplied to SPKW15 had length zero."
" The most likely cause of this problem is an uninitialized v"
"ector. ", (ftnlen)126);
sigerr_("SPICE(BADVECTOR)", (ftnlen)16);
chkout_("SPKW15", (ftnlen)6);
return 0;
} else if (*radius < 0.) {
setmsg_("The central body radius was negative. It must be zero or po"
"sitive. The value supplied was #. ", (ftnlen)94);
errdp_("#", radius, (ftnlen)1);
sigerr_("SPICE(BADRADIUS)", (ftnlen)16);
chkout_("SPKW15", (ftnlen)6);
return 0;
}
/* One final check. Make sure the pole and periapse vectors are */
/* orthogonal. (We will use a very crude check but this should */
/* rule out any obvious errors.) */
dot = vdot_(mypa, mytp);
if (abs(dot) > 1e-5) {
angle = vsep_(pa, tp) * dpr_();
setmsg_("The periapsis and trajectory pole vectors are not orthogona"
"l. The angle between them is # degrees. ", (ftnlen)99);
errdp_("#", &angle, (ftnlen)1);
sigerr_("SPICE(BADINITSTATE)", (ftnlen)19);
chkout_("SPKW15", (ftnlen)6);
return 0;
}
/* Make sure the segment identifier is not too long. */
if (lastnb_(segid, segid_len) > 40) {
setmsg_("Segment identifier contains more than 40 characters.", (
ftnlen)52);
sigerr_("SPICE(SEGIDTOOLONG)", (ftnlen)19);
chkout_("SPKW15", (ftnlen)6);
return 0;
}
/* Make sure it has only printing characters. */
i__1 = lastnb_(segid, segid_len);
for (i__ = 1; i__ <= i__1; ++i__) {
value = *(unsigned char *)&segid[i__ - 1];
if (value < 32 || value > 126) {
setmsg_("The segment identifier contains the nonprintable charac"
"ter having ascii code #.", (ftnlen)79);
errint_("#", &value, (ftnlen)1);
sigerr_("SPICE(NONPRINTABLECHARS)", (ftnlen)24);
chkout_("SPKW15", (ftnlen)6);
return 0;
}
}
/* All of the obvious checks have been performed on the input */
/* record. Create the segment descriptor. (FIRST and LAST are */
/* checked by SPKPDS as well as consistency between BODY and CENTER). */
spkpds_(body, center, frame, &c__15, first, last, descr, frame_len);
if (failed_()) {
chkout_("SPKW15", (ftnlen)6);
return 0;
}
/* Begin a new segment. */
dafbna_(handle, descr, segid, segid_len);
if (failed_()) {
chkout_("SPKW15", (ftnlen)6);
return 0;
}
dafada_(record, &c__16);
if (! failed_()) {
dafena_();
}
chkout_("SPKW15", (ftnlen)6);
return 0;
} /* spkw15_ */
