double palDat ( double dju ) {
int iy;
int im;
int id;
int status;
double fd;
double deltat;
eraJd2cal( PAL__MJD0, dju,
&iy, &im, &id, &fd );
status = eraDat( iy, im, id, fd, &deltat );
return deltat;
}
int eraUtcut1(double utc1, double utc2, double dut1,
double *ut11, double *ut12)
/*
** - - - - - - - - - -
** e r a U t c u t 1
** - - - - - - - - - -
**
** Time scale transformation: Coordinated Universal Time, UTC, to
** Universal Time, UT1.
**
** Given:
** utc1,utc2 double UTC as a 2-part quasi Julian Date (Notes 1-4)
** dut1 double Delta UT1 = UT1-UTC in seconds (Note 5)
**
** Returned:
** ut11,ut12 double UT1 as a 2-part Julian Date (Note 6)
**
** Returned (function value):
** int status: +1 = dubious year (Note 7)
** 0 = OK
** -1 = unacceptable date
**
** Notes:
**
** 1) utc1+utc2 is quasi Julian Date (see Note 2), apportioned in any
** convenient way between the two arguments, for example where utc1
** is the Julian Day Number and utc2 is the fraction of a day.
**
** 2) JD cannot unambiguously represent UTC during a leap second unless
** special measures are taken. The convention in the present
** function is that the JD day represents UTC days whether the
** length is 86399, 86400 or 86401 SI seconds.
**
** 3) The warning status "dubious year" flags UTCs that predate the
** introduction of the time scale and that are too far in the future
** to be trusted. See eraDat for further details.
**
** 4) The function eraDtf2d converts from calendar date and time of
** day into 2-part Julian Date, and in the case of UTC implements
** the leap-second-ambiguity convention described above.
**
** 5) Delta UT1 can be obtained from tabulations provided by the
** International Earth Rotation and Reference Systems Service. It
** It is the caller's responsibility to supply a DUT argument
** containing the UT1-UTC value that matches the given UTC.
**
** 6) The returned ut11,ut12 are such that their sum is the UT1 Julian
** Date.
**
** 7) The warning status "dubious year" flags UTCs that predate the
** introduction of the time scale and that are too far in the future
** to be trusted. See eraDat for further details.
**
** References:
**
** McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),
** IERS Technical Note No. 32, BKG (2004)
**
** Explanatory Supplement to the Astronomical Almanac,
** P. Kenneth Seidelmann (ed), University Science Books (1992)
**
** Called:
** eraJd2cal JD to Gregorian calendar
** eraDat delta(AT) = TAI-UTC
** eraUtctai UTC to TAI
** eraTaiut1 TAI to UT1
**
** Copyright (C) 2013, NumFOCUS Foundation.
** Derived, with permission, from the SOFA library. See notes at end of file.
*/
{
int iy, im, id, js, jw;
double w, dat, dta, tai1, tai2;
/* Look up TAI-UTC. */
if ( eraJd2cal(utc1, utc2, &iy, &im, &id, &w) ) return -1;
js = eraDat ( iy, im, id, 0.0, &dat);
if ( js < 0 ) return -1;
/* Form UT1-TAI. */
dta = dut1 - dat;
/* UTC to TAI to UT1. */
jw = eraUtctai(utc1, utc2, &tai1, &tai2);
if ( jw < 0 ) {
return -1;
} else if ( jw > 0 ) {
js = jw;
}
if ( eraTaiut1(tai1, tai2, dta, ut11, ut12) ) return -1;
/* Status. */
return js;
}
int eraUtctai(double utc1, double utc2, double *tai1, double *tai2)
/*
** - - - - - - - - - -
** e r a U t c t a i
** - - - - - - - - - -
**
** Time scale transformation: Coordinated Universal Time, UTC, to
** International Atomic Time, TAI.
**
** Given:
** utc1,utc2 double UTC as a 2-part quasi Julian Date (Notes 1-4)
**
** Returned:
** tai1,tai2 double TAI as a 2-part Julian Date (Note 5)
**
** Returned (function value):
** int status: +1 = dubious year (Note 3)
** 0 = OK
** -1 = unacceptable date
**
** Notes:
**
** 1) utc1+utc2 is quasi Julian Date (see Note 2), apportioned in any
** convenient way between the two arguments, for example where utc1
** is the Julian Day Number and utc2 is the fraction of a day.
**
** 2) JD cannot unambiguously represent UTC during a leap second unless
** special measures are taken. The convention in the present
** function is that the JD day represents UTC days whether the
** length is 86399, 86400 or 86401 SI seconds. In the 1960-1972 era
** there were smaller jumps (in either direction) each time the
** linear UTC(TAI) expression was changed, and these "mini-leaps"
** are also included in the ERFA convention.
**
** 3) The warning status "dubious year" flags UTCs that predate the
** introduction of the time scale or that are too far in the future
** to be trusted. See eraDat for further details.
**
** 4) The function eraDtf2d converts from calendar date and time of day
** into 2-part Julian Date, and in the case of UTC implements the
** leap-second-ambiguity convention described above.
**
** 5) The returned TAI1,TAI2 are such that their sum is the TAI Julian
** Date.
**
** Called:
** eraJd2cal JD to Gregorian calendar
** eraDat delta(AT) = TAI-UTC
** eraCal2jd Gregorian calendar to JD
**
** References:
**
** McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),
** IERS Technical Note No. 32, BKG (2004)
**
** Explanatory Supplement to the Astronomical Almanac,
** P. Kenneth Seidelmann (ed), University Science Books (1992)
**
** Copyright (C) 2013-2015, NumFOCUS Foundation.
** Derived, with permission, from the SOFA library. See notes at end of file.
*/
{
int big1;
int iy, im, id, j, iyt, imt, idt;
double u1, u2, fd, dat0, dat12, w, dat24, dlod, dleap, z1, z2, a2;
/* Put the two parts of the UTC into big-first order. */
big1 = ( utc1 >= utc2 );
if ( big1 ) {
u1 = utc1;
u2 = utc2;
} else {
u1 = utc2;
u2 = utc1;
}
/* Get TAI-UTC at 0h today. */
j = eraJd2cal(u1, u2, &iy, &im, &id, &fd);
if ( j ) return j;
j = eraDat(iy, im, id, 0.0, &dat0);
if ( j < 0 ) return j;
/* Get TAI-UTC at 12h today (to detect drift). */
j = eraDat(iy, im, id, 0.5, &dat12);
if ( j < 0 ) return j;
/* Get TAI-UTC at 0h tomorrow (to detect jumps). */
j = eraJd2cal(u1+1.5, u2-fd, &iyt, &imt, &idt, &w);
if ( j ) return j;
j = eraDat(iyt, imt, idt, 0.0, &dat24);
if ( j < 0 ) return j;
/* Separate TAI-UTC change into per-day (DLOD) and any jump (DLEAP). */
dlod = 2.0 * (dat12 - dat0);
dleap = dat24 - (dat0 + dlod);
/* Remove any scaling applied to spread leap into preceding day. */
fd *= (ERFA_DAYSEC+dleap)/ERFA_DAYSEC;
/* Scale from (pre-1972) UTC seconds to SI seconds. */
fd *= (ERFA_DAYSEC+dlod)/ERFA_DAYSEC;
/* Today's calendar date to 2-part JD. */
if ( eraCal2jd(iy, im, id, &z1, &z2) ) return -1;
/* Assemble the TAI result, preserving the UTC split and order. */
a2 = z1 - u1;
a2 += z2;
a2 += fd + dat0/ERFA_DAYSEC;
if ( big1 ) {
*tai1 = u1;
*tai2 = a2;
} else {
*tai1 = a2;
*tai2 = u1;
}
/* Status. */
return j;
}
int eraDtf2d(const char *scale, int iy, int im, int id,
int ihr, int imn, double sec, double *d1, double *d2)
/*
** - - - - - - - - -
** e r a D t f 2 d
** - - - - - - - - -
**
** Encode date and time fields into 2-part Julian Date (or in the case
** of UTC a quasi-JD form that includes special provision for leap
** seconds).
**
** Given:
** scale char[] time scale ID (Note 1)
** iy,im,id int year, month, day in Gregorian calendar (Note 2)
** ihr,imn int hour, minute
** sec double seconds
**
** Returned:
** d1,d2 double 2-part Julian Date (Notes 3,4)
**
** Returned (function value):
** int status: +3 = both of next two
** +2 = time is after end of day (Note 5)
** +1 = dubious year (Note 6)
** 0 = OK
** -1 = bad year
** -2 = bad month
** -3 = bad day
** -4 = bad hour
** -5 = bad minute
** -6 = bad second (<0)
**
** Notes:
**
** 1) scale identifies the time scale. Only the value "UTC" (in upper
** case) is significant, and enables handling of leap seconds (see
** Note 4).
**
** 2) For calendar conventions and limitations, see eraCal2jd.
**
** 3) The sum of the results, d1+d2, is Julian Date, where normally d1
** is the Julian Day Number and d2 is the fraction of a day. In the
** case of UTC, where the use of JD is problematical, special
** conventions apply: see the next note.
**
** 4) JD cannot unambiguously represent UTC during a leap second unless
** special measures are taken. The ERFA internal convention is that
** the quasi-JD day represents UTC days whether the length is 86399,
** 86400 or 86401 SI seconds. In the 1960-1972 era there were
** smaller jumps (in either direction) each time the linear UTC(TAI)
** expression was changed, and these "mini-leaps" are also included
** in the ERFA convention.
**
** 5) The warning status "time is after end of day" usually means that
** the sec argument is greater than 60.0. However, in a day ending
** in a leap second the limit changes to 61.0 (or 59.0 in the case
** of a negative leap second).
**
** 6) The warning status "dubious year" flags UTCs that predate the
** introduction of the time scale or that are too far in the future
** to be trusted. See eraDat for further details.
**
** 7) Only in the case of continuous and regular time scales (TAI, TT,
** TCG, TCB and TDB) is the result d1+d2 a Julian Date, strictly
** speaking. In the other cases (UT1 and UTC) the result must be
** used with circumspection; in particular the difference between
** two such results cannot be interpreted as a precise time
** interval.
**
** Called:
** eraCal2jd Gregorian calendar to JD
** eraDat delta(AT) = TAI-UTC
** eraJd2cal JD to Gregorian calendar
**
** Copyright (C) 2013-2014, NumFOCUS Foundation.
** Derived, with permission, from the SOFA library. See notes at end of file.
*/
{
int js, iy2, im2, id2;
double dj, w, day, seclim, dat0, dat12, dat24, dleap, time;
/* Today's Julian Day Number. */
js = eraCal2jd(iy, im, id, &dj, &w);
if ( js ) return js;
dj += w;
/* Day length and final minute length in seconds (provisional). */
day = ERFA_DAYSEC;
seclim = 60.0;
/* Deal with the UTC leap second case. */
if ( ! strcmp(scale,"UTC") ) {
/* TAI-UTC at 0h today. */
js = eraDat(iy, im, id, 0.0, &dat0);
if ( js < 0 ) return js;
/* TAI-UTC at 12h today (to detect drift). */
js = eraDat(iy, im, id, 0.5, &dat12);
if ( js < 0 ) return js;
/* TAI-UTC at 0h tomorrow (to detect jumps). */
js = eraJd2cal ( dj, 1.5, &iy2, &im2, &id2, &w);
if ( js ) return js;
js = eraDat(iy2, im2, id2, 0.0, &dat24);
if ( js < 0 ) return js;
/* Any sudden change in TAI-UTC between today and tomorrow. */
dleap = dat24 - (2.0*dat12 - dat0);
/* If leap second day, correct the day and final minute lengths. */
day += dleap;
if ( ihr == 23 && imn == 59 ) seclim += dleap;
/* End of UTC-specific actions. */
}
/* Validate the time. */
if ( ihr >= 0 && ihr <= 23 ) {
if ( imn >= 0 && imn <= 59 ) {
if ( sec >= 0 ) {
if ( sec >= seclim ) {
js += 2;
}
} else {
js = -6;
}
} else {
js = -5;
}
} else {
js = -4;
}
if ( js < 0 ) return js;
/* The time in days. */
time = ( 60.0 * ( (double) ( 60 * ihr + imn ) ) + sec ) / day;
/* Return the date and time. */
*d1 = dj;
*d2 = time;
/* Status. */
return js;
}
