Hello,
I have used the tutorials to try injecting sources into a visit image and that works as expected. However, something I would like to try is injecting a source using a manually modified PSF. Essentially this would test the situation where the PSF produced from the pipelines is slightly incorrect, and how that would propagate into measurements. Currently, it seems to only be possible to pass a lsst.afw.detection.Psf object which I think is a wrapper over Piff if I understood the docs correctly. But I would really like to just pass a 2D array or some other simple object to be used by the injection system. Here’s a cutout of the code showing what I tried:
my_injection_catalog = Table(
{
'injection_id': [9999],
'ra': [inject_ra_dec[0]],
'dec': [inject_ra_dec[1]],
"seed": ["123"],
'source_type': ['Star'],
'mag': [21.8],
}
)
inject_config = VisitInjectConfig()
inject_task = VisitInjectTask(config=inject_config)
psf = visit_img.psf.clone()
sn_point = geom.Point2D(ij[0], ij[1])
psf_pix = psf.computeImage(sn_point)
psf_pix.array[10] = 0 # some modification to the PSF
injected_output = inject_task.run(
injection_catalogs=my_injection_catalog,
input_exposure=visit_img.clone(),
psf=psf_pix,
photo_calib=visit_img.photoCalib,
wcs=visit_img.wcs,
)
injected_exposure = injected_output.output_exposure
injected_catalog = injected_output.output_catalog
Which didn’t work, it produced this error:
TypeError Traceback (most recent call last)
Cell In[20], line 31
28 psf_pix = psf.computeImage(sn_point)
29 psf_pix.array[10] = 0 # some modification to the PSF
---> 31 injected_output = inject_task.run(
32 injection_catalogs=my_injection_catalog,
33 input_exposure=visit_img.clone(),
34 psf=psf_pix,
35 photo_calib=visit_img.photoCalib,
36 wcs=visit_img.wcs,
37 )
38 injected_exposure = injected_output.output_exposure
39 injected_catalog = injected_output.output_catalog
File /opt/lsst/software/stack/conda/envs/lsst-scipipe-10.1.0/share/eups/Linux64/source_injection/g373392b20a+78a5bceb3f/python/lsst/source/injection/inject_base.py:216, in BaseInjectTask.run(self, injection_catalogs, input_exposure, psf, photo_calib, wcs)
214 original_photo_calib = input_exposure.getPhotoCalib()
215 original_wcs = input_exposure.getWcs()
--> 216 input_exposure.setPsf(psf)
217 input_exposure.setPhotoCalib(photo_calib)
218 input_exposure.setWcs(wcs)
TypeError: setPsf(): incompatible function arguments. The following argument types are supported:
1. (self: lsst.afw.image._exposure.ExposureF, psf: lsst.afw.detection.Psf) -> None
Invoked with: <lsst.afw.image._exposure.ExposureF object at 0x7db0270bd1b0>, lsst.afw.image._image.ImageD=[[-2.14661988e-04 -8.14682781e-05 1.94507816e-05 1.86314248e-04
...
If I have missed something obvious and there is a way to manually modify the injection PSF that would be great. Otherwise, perhaps this could be a feature to add for the next update?
Thanks!