Corrections to the net counts are applied if the proper calibration information are available for that instrument. Count rate errors include both statistical and systematic uncertainties added quadratically. To minimize the number of spurious sources detected the threshold used by detect is somewhat conservative. Consequently, some sources with intensity just above the image background can be missed. In order to allow detect to obtain a sufficiently good estimate of the background only images of size 128x128 pixels or larger should be used.
Maximum accuracy is obtained running detect on full resolution images.
This will make a weighted mean of each excess, and optimizing the psf. Consequently it can take much longer to run. The functionality of the detect command may also be accessed by executing the background , excess , and search commands in succession. Running the process in pieces allows for finer control of each step. The latter mode is useful for checking how good the detect run was.