NPOESS VIIRS polarization dependent optical crosstalk

ABSTRACT: The Visible Infrared Imaging Radiometer Suite (VIIRS) is being developed by Raytheon Space and Airborne Systems under contract with Northrop Grumman Space Technology for the U.S. Government National Polar-orbiting Operational Environmental Satellite System (NPOESS). During the ground tests of VIIRS F1 sensor for the NASA NPOESS Preparatory Project (NPP), significant optical crosstalk in VisNIR bands was observed. The optical crosstalk has been attributed mainly to angle resolved scattering (ARS) from the incident light passing through the integrated filter assembly (IFA). More recently Peter Fuqua at Aerospace has found that ARS can depend strongly on the polarization of the incident light. In order to address such a polarization dependence and the filter spread function of the optical crosstalk, Raytheon has conducted optical crosstalk tests by illuminating a single detector using a spot light obtained by inserting a wired grid polarizer and a cross-slit reticule at the output of the Spectral Measurement Assembly (SpMA). We will report the results of the crosstalk influence coefficient as functions of polarization angles for several VisNIR detectors, bands, and wavelengths. The polarization sensitivity of the same-band and band-to-band optical crosstalk will be assessed in terms of the degree of polarization and phase angle. In addition the filter spread function of the crosstalk will also be discussed.