DM-16490: Update computeCcdOffsets() to use makeSkyWcs #17
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This update deprecates the pixelScale configuration parameter which is no longer necessary now that all the camera units are correct and makeSkyWcs works properly for HSC. However, due to a bug in the data files in testdata_jointcal, there is still an HSC-specific hack that can be fixed after DM-17597 is complete.
python/lsst/fgcmcal/fgcmFitCycle.py
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| @@ -214,11 +214,12 @@ class FgcmFitCycleConfig(pexConfig.Config): | |||
| dtype=float, | |||
| default=None, | |||
| ) | |||
| # TODO: DM-16490 will make this unneccessary | |||
| # pixelScale is deprecated by DM-16490. | |||
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This comment should go into the deprecated field: it's not necessary here.
| boresight = geom.SpherePoint(180.0*geom.degrees, 0.0*geom.degrees) | ||
| # TODO: DM-17597 will update testdata_jointcal so that the test data | ||
| # does not have nan as the boresight angle for HSC data. For the | ||
| # time being, there is this ungainly hack. |
| # along with this program. If not, see <https://www.gnu.org/licenses/>. | ||
| """Test the fgcmcal computeCcdOffsets code with testdata_jointcal. | ||
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| """ |
python/lsst/fgcmcal/utilities.py
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| pixelsToFieldAngle = detector.getTransform(detector.makeCameraSys(PIXELS), | ||
| detector.makeCameraSys(FIELD_ANGLE)) | ||
| wcs = afwGeom.makeSkyWcs(pixelsToFieldAngle, orientation, flipX, boresight) |
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Is there a reason you can't use obs.base.utils.createInitialSkyWcs here instead? Or just use the stack-generated WCS instead of creating your own?
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At first I didn't use obs.base.utils.createInitialSkyWcs() because of the workflow (extracting all the visit details and extracting stars before the actual run begins) didn't have access to the visitInfo. And this ccdOffset structure is used primarily for visualization and also some airmass corrections. But the fgcm code doesn't handle rotations properly yet (hence the TODO) so I'll have to revisit some of these assumptions.
But when responding to this comment I realized I could still create a fake visitInfo and call createInitialSkyWcs and save a couple lines. So this is what I've now done (and maybe this is what you had in mind). Furthermore, by creating the fake visitInfo I can still patch the rotation angle from testdata_jointcal.
| self.assertGreater(ccdOffsets['DEC_SIZE'][i], 0.17) | ||
| self.assertLess(ccdOffsets['DEC_SIZE'][i], 0.20) | ||
| self.assertGreater(ccdOffsets['RA_SIZE'][i], 0.07) | ||
| self.assertLess(ccdOffsets['RA_SIZE'][i], 0.10) |
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Where did these sizes come from, and what are the units here? Why the 0.03 range in each case? Please document that in the code.
This update deprecates the pixelScale configuration parameter which is no
longer necessary now that all the camera units are correct and makeSkyWcs works
properly for HSC. However, due to a bug in the data files in
testdata_jointcal, there is still an HSC-specific hack that can be fixed after
DM-17597 is complete.