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jointcalshall be runnable as a command-lineTaskthat takes thesrcandref_catdatasets as input and produces (at least) awcsandphotoCalibdataset as outputs, which provide updated astrometric and photometric calibrations.jointcalshall perform a different fit for each tract, and allow multiple tracts to be run in single invocation (at least in serial, which is allmeas_mosaicdoes). Some visits may thus be processed with multiple tracts.jointcalshall fit models that have a level of sophistication similar to those inmeas_mosaic(if it fits simpler models, it will be because the tests below demonstrate that they are sufficient to generate similar-quality results). That involves:- astrometry: a full-focal-plane polynomial transform for each visit composed with a rotation and translation for each CCD (which is the same for all visits in the fit).
- photometry: a full-focal-plane polynomial scaling for each visit multiplied by a constant scaling for each CCD (which is the same for all visits in the fit) and the determinant of the Jacobian of the astrometric model.
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We will run the metric comparison independently on each of at least 19 tracts of HSC-SSP Wide data, as well as the (single tract) HSC-SSP UDeep COSMOS dataset. No more than 1 of these 20 tracts shall have a regression from the meas_mosaic performance in that tract by more than 2σ, and none may deviate by more than 3σ. The number of tracts may be extended if initial failure to achieve these rates appears to be due to statistical fluctuations.
The WCS mappings and photometric scalings output by meas_mosaic and jointcal should also be manually inspected for at least 5 visits in each of 5 tracts (including COSMOS) to look for unusual differences.
Doing the Work
Scheduling work is obviously a T/CAM responsibility, but it may be best to try to share the generation of the input data repositories for these tests with re-run of the full HSC-SSP PDR1 (NCSA may have already scheduled some time for this later this cycle).
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