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Caltech-IPAC / kete

Kete Solar System Survey tools
https://Caltech-IPAC.github.io/kete
BSD 3-Clause "New" or "Revised" License
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Add support for querying JPL Horizons `sbdb_query` #134

Open dahlend opened 2 hours ago

dahlend commented 2 hours ago

The MPC generated orbit file has truncated values in the orbital parameters. Typically this leads to a few hundred km error, which is good enough for most work. However we can get higher precision values out of the API from Horizons:

"https://ssd-api.jpl.nasa.gov/sbdb_query.api?fields=pdes,spkid,orbit_id,rms,H,diameter,epoch,e,i,q,w,tp,om,A1,A2,A3,DT&full-prec=1&sb-xfrag=1"

This query to the sbdb on horizons includes a full-precision query which returns more digits, excludes comet fragments, along with non-gravitational forces, diameter fits, and spice kernel ID values. I plan to codify this into the horizons.py file with saving into the kete cache, and switch to using this for the semi-default tests as ground truth.

This should help with the baseline precision when doing testing of the full catalog, as it should decrease the positional uncertainty by about 1000km in many cases.

dahlend commented 2 hours ago

Unfortunately there does not appear to be any API to query the covariance matrices of the fits at large scale, and can only be done on a single object basis.