Re: [Orekit Developers] Removing derivatives in GAST, GMST, ... functions from IERSConventions

[Hank Grabowski <hank@applieddefense.com>]

I don't believe we use them at all on any of our projects.

On Wed, Jan 4, 2017 at 5:49 AM, MAISONOBE Luc <luc.maisonobe@c-s.fr> wrote:

Hi all,

The getGASTFunction, getGMSTFunction as well as some internal private classes like
StellarAngleCapitaine do return DerivativeStructure to include the first time
derivative of the Earth rotation.

However, it seems this derivative is never really used by Orekit itself, since some
changes months or years ago (probably when we did the last speed improvement in
Earth transforms).

I would like to remove this derivative and simply return a double with the angle
itself, as it would greatly simplify porting these methods to Field.

Does anyone use these derivatives directly or can I change the return type from
TimeFunction<DerivativeStructure> to TimeFunction<Double>?

best regards,
Luc