We are trying to run detectCoaddSource on emulated HSC Coadd with VISTA data. The background is not well subtracted. This leads to a huge correction of the inputed threshold and the increase of false detection in the end. We would like to know if there is a way not to modify the configured detection threshold after the detection of the sky sources like it is done in this example ?
detectCoaddSources.py . --rerun RERUN --id tract=9813 patch=4,4 filter=VIRCAM-J --clobber-config --clobber-version --config detection.thresholdValue=5.0 doScaleVariance=True
detectCoaddSources.scaleVariance INFO: Renormalizing variance by 0.856342 detectCoaddSources.detection INFO: Applying temporary wide background subtraction detectCoaddSources.detection INFO: Detected 44011 positive peaks in 4645 footprints to 2.5 sigma detectCoaddSources.detection.skyObjects INFO: Added 528 of 1000 requested sky sources (53%) detectCoaddSources.detection.skyMeasurement INFO: Performing forced measurement on 528 sources detectCoaddSources.detection INFO: Modifying configured detection threshold by factor 0.327976 to 1.639878 detectCoaddSources.detection INFO: Tweaking background by -0.307181 to match sky photometry detectCoaddSources.detection INFO: Detected 32690 positive peaks in 3064 footprints to 1.63988 sigma detectCoaddSources.detection INFO: Detected 63323 positive peaks in 2028 footprints to 1.63988 sigma detectCoaddSources.detection.skyObjects INFO: Added 170 of 1000 requested sky sources (17%) detectCoaddSources.detection.skyMeasurement INFO: Performing forced measurement on 170 sources detectCoaddSources.detection INFO: Tweaking background by -0.246550 to match sky photometry
Also, we noticed in our tests that the default setting for config.detection.thresholdType=‘pixel_stdev’ but the results improve when set to ‘stdev’ with the same detection threshold. What is the difference between the two exactly ?
Thanks a lot in advance for your help.