subtract_visit_angle_averages

grizli.prep.subtract_visit_angle_averages(visit, threshold=1.8, detection_background=True, angles=[30.0, -30.0, 0, 90], suffix='angles', niter=3, weight_type='jwst', instruments=['NIRCAM'], stepsize=-1, verbose=True)

Subtract angle averages from exposures in a visit group

Parameters

visitdict

Visit association dictionary

thresholdfloat

Detection threshold for source masking

detection_backgroundbool

Run source mask detection with background estimation

angleslist

List of angles relative to PA_APER to compute. For JWST/NIRCam, the diffraction spikes are at approximately +/- 30 deg.

suffixstr

If provided, write an output file of the drizzle-combined angle background image

niterint

Number of iterations. A few iterations seems to help, perhaps because of imperfect mapping between the exposure frame and the drizzled frame where the correction is derived

instrumentslist

Only perform if exposure instrument is in this list

stepsizeint

Parameter for blot

Returns

hduHDUList

FITS data with the drizzled data and angle averages