Drizzlepac does not account for the different sensitivities of multiple chips - Is this an issue?

spacetelescope / drizzlepac

AstroDrizzle for HST images.

https://drizzlepac.readthedocs.io

BSD 3-Clause "New" or "Revised" License

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Drizzlepac does not account for the different sensitivities of multiple chips - Is this an issue? #559

Open mdlpstsci opened 4 years ago

mdlpstsci commented 4 years ago

Check as there looks like a bug in the measure_sources() method for both catalogs. The call to the iraf_style_photometry() function includes the PHOTFLAM value. This value is being read from extension 1 of the input file (hard-coded). However, for WFC3/IR the PHOTFLAM keyword is in the Primary. Check all photometry related keys to ensure they are being read from the proper headers. It is not clear why the current code does not throw an exception.

mdlpstsci commented 4 years ago

This issue may not be a bug afterall depending if the code is reading the FLT/FLC files or the drizzle products associated with these files.

The real issue here is that Drizzlepac does not account for the different sensitivities of the different chips in the drizzled product and is dependent somewhat at what has been done in the calibration pipelines. Also, calacs and calwf3 handle certain calibrations differently. This should be verified with the Instrument Teams.