mirror of
https://github.com/cosinekitty/astronomy.git
synced 2025-12-23 23:58:15 -05:00
b005bdef5a
I realize some use cases require adjustments for stellar aberration. The existing aberration adjustments are only supplied for calculating planet positions. Some users will benefit from being able to add/subtract aberration corrections to arbitrary vectors, including for star positions. I have added some JPL Horizons test data to help validate the aberration functionality I'm about to add. I created the beginning of a unit test in ctest.c, but currently there is no aberration correction implemented, so the test has no error threshold.
Data for testing EQJ/EQD conversion.
I generated this data using JPL Horzions to test Astronomy Engine's conversion between J2000 equatorial coordinates (EQJ) and equator-of-date coordinates (EQD).
The first pair of RA/DEC are in ICRF, which is very close to Astronomy Engine EQJ. The second pair of RA/DEC are apparent coordinates, which is close to Astronomy Engine EQD, but also with aberration correction.
So my test algorithm will need to correct for aberration also.
Here are the batch settings to reproduce the data:
!$$SOF
COMMAND= '499'
CENTER= 'coord'
COORD_TYPE= 'GEODETIC'
SITE_COORD= '-77.06580,+38.92056,0'
MAKE_EPHEM= 'YES'
TABLE_TYPE= 'OBSERVER'
START_TIME= '2021-06-06'
STOP_TIME= '2031-06-06'
STEP_SIZE= '10 d'
CAL_FORMAT= 'JD'
TIME_DIGITS= 'MINUTES'
ANG_FORMAT= 'DEG'
OUT_UNITS= 'KM-S'
RANGE_UNITS= 'AU'
APPARENT= 'AIRLESS'
SUPPRESS_RANGE_RATE= 'NO'
SKIP_DAYLT= 'NO'
EXTRA_PREC= 'YES'
R_T_S_ONLY= 'NO'
REF_SYSTEM= 'J2000'
CSV_FORMAT= 'NO'
OBJ_DATA= 'YES'
QUANTITIES= '1,2'
!$$EOF