This package performs astrometry and photometry across multiple visits of the same field, fitting models for the astrometric distortions and photometric calibrations of the CCDs and focal plane.
It was derived from meas_simastrom.
A note on numbers in tests
All of the
tests/test_jointcal_<obs>.py tests run jointcal on their respective
The numeric values being tested (the
metrics dictionary, and the
dist_absolute_rms values) were not computed in advance, but are empirical, from the first time that test was successfully run.
The one exception is the
cfht_minimal dataset, which was designed to be small enough (3
RefStar) that the "correct" answers could be computed in advance with e.g. Mathematica.
They are updated when changes to the algorithm warrants, e.g. a change to outlier rejection that affects the final chi2/ndof for some of the testdata.
pa1 (see LPM-17 table 14) and relative/absolute rms (related to, but not the same as LPM-17's AM1 in table 18) values should be considered regression tests: algorithmic changes shouldn't result in larger values, but could produce smaller ones.
They are "measured value must be less than" tests, and the calculations are in
More sophisticated testing of jointcal's validity is handled by
validate_drp on much larger datasets that have multiple full-focal plane visits.