Default template files have been created that specify the spatial pixel numbers to be avoided in the Pass 1 background extraction for each camera and for all source types (point, extended, and noncontinuum) sources. The file also includes values for nc, nf, and nd of the IOR. Initially, the list of spatial positions to be avoided includes only the starting and ending values and the echelle order positions, but this is modified for a particular image in the initial Data Screening step (Section A.2.1) from the flags determined in the raw image screening (RAW_SCREEN) step.
Figure A.2: Crosscut of background fluxes from a central ``Pass 1" swath through an SWP image. Stellar fluxes are off-scale in this diagram. The triangular area describes the local raw background fluxes in the Interorder-Overlap Region where order crowding is severe; the halation region is shown to the right. Small crosses denote the raw fluxes corrected for overlap by the PSF model. The solid line is the Pass 1 solution, a Chebyshev, degree-7 polynomial.