Read parameters Open and read full FOV image FITS file (780x780 I32 array plus attributes). Open and read full FOV spectum FITS file, extract BACKSCALE. call CAL_spdetmap to get Soft Proton DETMAP for inst and filter. Loop through both image array and SPDETMAP array to find SP contribution n = 0 spfull = 0. do i=0,fimgXsize-1 do ii=0,fimgYsize-1 if (fimage_IP(i,ii) .gt. 0) then n = n + 1 spfull = spfull + spdetmap_RP(i,ii) endif enddo enddo spfull = spfull / real(n) Repeat for user-selected region image and spectrum n = 0 spregion = 0. do i=0,rimgXsize-1 do ii=0,rimgYsize-1 if (rimage_IP(i,ii) .gt. 0) then n = n + 1 spregion = spregion + spdetmap_RP(i,ii) endif enddo enddo spregion = spregion / real(n) rrnorm = rnorm * (backFOV/backREG) * (spfull/spregion) Print rrnorm, backscale values