ICRF -> TEME

[randyg3000]

Hi Folks,

Given a state vector in ICRF coordinates, is it possible to use skyfield to transform that vector into the TEME frame? A bit of a corner case I presume, but useful for our particular circumstance. (It does appear that skyfield provides the inverse of what I'm asking for in the TEME class).

Thanks in advance for any help!

[randyg3000]

I believe I have an answer to my own question here:

            ######################################
            # convert TDB to UTC                 #
            ######################################
            t = ts.tdb_jd(
                JDTDB
            )  # Note that this will use delta_t from downloaded finals2000A.all

            ######################################
            # convert ICRF TO TEME               #
            ######################################
            icrf_vector = ICRF(
                t=t,
                position_au=Distance(km=[x, y, z]).au,
                velocity_au_per_d=Velocity(km_per_s=[vx, vy, vz]).au_per_d,
            )
            d, v = icrf_vector.frame_xyz_and_velocity(TEME)
            print(f"{d.km}, {v.km_per_s}")