There is a bunch of effective-area code in foxsi_get_output_image_cube.pro. This code appears to take great pains to accurately interpolate effective areas between areas provided by foxsi_get_effective_area.pro, which itself already has (simpler?) interpolation capabilities via foxsi_get_optics_effective_area.pro. If the code in foxsi_get_output_image_cube.pro is the right approach, then it should be ripped out of there and put into foxsi_get_effective_area.pro.
There is a bunch of effective-area code in
foxsi_get_output_image_cube.pro. This code appears to take great pains to accurately interpolate effective areas between areas provided byfoxsi_get_effective_area.pro, which itself already has (simpler?) interpolation capabilities viafoxsi_get_optics_effective_area.pro. If the code infoxsi_get_output_image_cube.prois the right approach, then it should be ripped out of there and put intofoxsi_get_effective_area.pro.