I have 4 band Planet Scope multispectral imagery that I am trying to process in ENVI. It is the analytic data, so it is already radiometrically corrected. I have converted the .tif to a BIL, and done the band specific calculations to get TOA reflectance (from the metadata). I want to do the FLAASH atmospheric correction, but in the hyperspectral tab of the FLAASH window, it requires a filter function file that is specific to the sensor being used. Usually, with a known sensor, this filter function file gets automatically uploaded because ENVI saves .hdr and .sli files of many known sensors. I have ENVI 5.3 (and dont have the capabilities to upgrade). In ENVI 5.5 they include the Planet Scope sensor and its filter details.

Does anyone know how to create a filter file for planet scope, and/or the format required for the file?