A fix for pre-1962-Jan-20 observations

[matthewholman]

Fixes #1145

This adds code to use IAU_EARTH rather than ITRF for observations before 1962-Jan-20. Thank you, Rahil!

Review Checklist for Source Code Changes

• Does pip install still work?
• Have you written a unit test for any new functions?
• Do all the units tests run successfully?
• Does Sorcha run successfully on a test set of input files/databases?
• Have you used black on the files you have updated to confirm python programming style guide enforcement?

[mschwamb]

Not sure if this PR is ready for review or not. Happy to review if it's ready. Note - the linter check is failing so black needs to be run on the files (I can do that if needed).

[matthewholman]

I still need to run comparisons with JPL Horizons and add unit tests.

[mschwamb]

JOSS review hasn't happened so any new additions will be reviewed - can we remove the commented out rows so we don't get asked to clean up during JOSS review?

[mschwamb]

Okay. Add @bernardinelli back to review to signal when this is ready for review so this is PR not approved prematurely. This branch of sorcha can be pip installed -e so it's not holding up layup development at the moment while those checks are being done and the unit test test is being developed.

[matthewholman]

Yes, that's fine. I left the old code there just for comparison.

…

On Sun, Apr 27, 2025 at 10:43 AM Meg Schwamb ***@***.***> wrote: ***@***.**** commented on this pull request. ------------------------------ In src/sorcha/ephemeris/simulation_geometry.py <#1144 (comment)> : > @@ -195,9 +195,19 @@ def barycentricObservatoryRates(et, obsCode, observatories, Rearth=RADIUS_EARTH_ pos = posvel[0:3] vel = posvel[3:6] # Get the matrix that rotates from the Earth's equatorial body fixed frame to the J2000 equatorial frame. - m = spice.pxform("ITRF93", "J2000", et) - mp = spice.pxform("ITRF93", "J2000", et + delta_et) - mm = spice.pxform("ITRF93", "J2000", et - delta_et) + # We don't need to compute this repeatedly + et_1962 = spice.str2et("1962-Jan-20") + if et >= et_1962: + m = spice.pxform("ITRF93", "J2000", et) + mp = spice.pxform("ITRF93", "J2000", et + delta_et) + mm = spice.pxform("ITRF93", "J2000", et - delta_et) + else: + m = spice.pxform("IAU_EARTH", "J2000", et) + mp = spice.pxform("IAU_EARTH", "J2000", et + delta_et) + mm = spice.pxform("IAU_EARTH", "J2000", et - delta_et) + # m = spice.pxform("ITRF93", "J2000", et) JOSS review hasn't happened so any new additions will be reviewed - can we remove the commented out rows so we don't get asked to clean up during JOSS review? — Reply to this email directly, view it on GitHub <#1144 (review)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AA5CVWOAAT4CPHOVFR6RG4323TUHLAVCNFSM6AAAAAB34VQOI2VHI2DSMVQWIX3LMV43YUDVNRWFEZLROVSXG5CSMV3GSZLXHMZDOOJXGY2TSNJVGY> . You are receiving this because you authored the thread.Message ID: ***@***.***>

-- Matthew J. Holman, PhD Senior Astrophysicist Center for Astrophysics | Harvard & Smithsonian 60 Garden Street, MS #51 Cambridge, MA 02138 (617) 496-7775

[mschwamb]

Looks good - thanks @bernardinelli for getting this over then line with the unit test - thanks @matthewholman for starting the fix.