Search found 2 matches

by PatrickChevalley
08 Jun 2019, 23:46
Forum: ASTAP General
Topic: Astrometry: Looking for Pascal/Delphi functions
Replies: 25
Views: 52838

Re: Astrometry: Looking for Pascal/Delphi functions

The nutation is not automatically applied to the planet coordinates, the result from the jpl function is always J2000. When you call the jpl computation for "planet" 14 you get the values to make the nutation matrix at the given date instead of a planet coordinates. Then you rotate with this matrix ...
by PatrickChevalley
08 Jun 2019, 09:25
Forum: ASTAP General
Topic: Astrometry: Looking for Pascal/Delphi functions
Replies: 25
Views: 52838

Re: Astrometry: Looking for Pascal/Delphi functions

You can get precise nutation from the JPL ephemeris. Just be sure to use a file that include the nutation, DE430 and DE431 are OK.

Here the code use in CdC to get the nutation parameters for a date:
https://github.com/pchev/skychart/blob/ ... .pas#L3705

Patrick