(Updated to reflect newer no junk suppression run, see DM-8044)
The cosmos and wide field RC datasets have been run through meas_mosaic. The following lists a comparison of the scatter in the astrometry and photometry (as measured by meas_mosaic and printed in the output diagnostic plots) from both stacks. Note that differences are expected given the slightly different data going into the analysis (see above comment on single frame processing successes vs. failures). In particular, since the LSST pipeline often had a few more successes, it is perhaps not surprising for the scatter to increase somewhat given that these are CCDs that the HSC stack had difficulty getting an initial WCS fit for.
Note:
ext == external catalog matched objects
|
int == internal objects (i.e. those with no matching external catalog object)
|
Astrometry (just listing eta sigmas) cosmos: LSST [HSC]
Filter |
sig_all (arcsec) |
sig_ext |
sig_int |
HSC-G |
0.008 [0.007] |
0.025 [0.024] |
0.005 [0.005] |
HSC-R |
0.009 [0.006] |
0.025 [0.023] |
0.005 [0.004] |
HSC-I |
0.011 [0.007] |
0.026 [0.025] |
0.005 [0.004] |
HSC-Z |
0.014 [0.009] |
0.030 [0.028] |
0.004 [0.004] |
HSC-Y |
0.015 [0.013] |
0.026 [0.025] |
0.007 [0.007] |
NB0921 |
0.009 [0.007] |
0.027 [0.028] |
0.004 [0.004] |
Astrometry wide tract 8766: LSST [HSC]
Filter |
sig_all (arcsec) |
sig_ext |
sig_int |
HSC-G |
0.013 [0.011] |
0.026 [0.025] |
0.005 [0.007] |
HSC-R |
0.018 [0.014] |
0.024 [0.024] |
0.005 [0.007] |
HSC-I |
0.015 [0.009] |
0.028 [0.027] |
0.005 [0.005] |
HSC-Z |
0.016 [0.010] |
0.030 [0.029] |
0.005 [0.006] |
HSC-Y |
0.015 [0.010] |
0.026 [0.027] |
0.004 [0.005] |
Astrometry wide tract 8767: LSST [HSC]
Filter |
sig_all (arcsec) |
sig_ext |
sig_int |
HSC-G |
0.013 [0.011] |
0.026 [0.025] |
0.005 [0.007] |
HSC-R |
0.018 [0.014] |
0.025 [0.024] |
0.005 [0.007] |
HSC-I |
0.015 [0.009] |
0.029 [0.028] |
0.005 [0.005] |
HSC-Z |
0.016 [0.011] |
0.029 [0.028] |
0.005 [0.006] |
HSC-Y |
0.015 [0.010] |
0.027 [0.027] |
0.004 [0.005] |
Photometry (sigma of Delta(mag)) cosmos: LSST [HSC]
Filter |
sig_all (mag) |
sig_ext |
sig_int |
HSC-G |
0.019 [0.017] |
0.020 [0.014] |
0.019 [0.019] |
HSC-R |
0.027 [0.020] |
0.030 [0.017] |
0.026 [0.021] |
HSC-I |
0.025 [0.019] |
0.028 [0.018] |
0.023 [0.019] |
HSC-Z |
0.019 [0.014] |
0.019 [0.012] |
0.020 [0.015] |
HSC-Y |
0.027 [0.020] |
0.031 [0.019] |
0.023 [0.020] |
NB0921 |
0.021 [0.016] |
0.023 [0.016] |
0.020 [0.016] |
Photometry wide tract 8766: LSST [HSC]
Filter |
sig_all (arcsec) |
sig_ext |
sig_int |
HSC-G |
0.025 [0.025] |
0.030 [0.021] |
0.021 [0.027] |
HSC-R |
0.034 [0.024] |
0.039 [0.021] |
0.022 [0.028] |
HSC-I |
0.026 [0.021] |
0.022 [0.015] |
0.028 [0.030] |
HSC-Z |
0.021 [0.029] |
0.017 [0.011] |
0.025 [0.030] |
HSC-Y |
0.036 [0.032] |
0.038 [0.025] |
0.035 [0.043] |
Photometry wide tract 8767: LSST [HSC]
Filter |
sig_all (arcsec) |
sig_ext |
sig_int |
HSC-G |
0.025 [0.024] |
0.030 [0.020] |
0.021 [0.027] |
HSC-R |
0.032 [0.024] |
0.039 [0.021] |
0.020 [0.028] |
HSC-I |
0.024 [0.020] |
0.021 [0.014] |
0.026 [0.027] |
HSC-Z |
0.019 [0.017] |
0.016 [0.011] |
0.021 [0.026] |
HSC-Y |
0.034 [0.031] |
0.036 [0.024] |
0.032 [0.040] |
My conclusion from the above is that the comparisons after the meas_mosaic processing stage look very good.
In his review of
DM-2674, John Swinbank asks:Would it be straightforward to address this in the context of this ticket (I suppose it would require a profiling to have been tracked in the HSC run)?