Simulation of LWIR polarimetric observations of space objects

SAIC's 3D LWIR spectropolarimetric signature model, Polar Heat, is used to simulate LWIR polarimetric observations of space objects. Both imaging and nonimaging simulated observations are presented for spinning and tumbling satellites, as well as RVs (reentry vehicles) and decoys. Polar Heat is a 1/sup st/ principle model that extends microfacet-based scattering models from intensity to polarimetric using a computational approach that utilizes the Born Wolf coherence matrix to integrate reflected and self-emitted radiation seamlessly. Thermal self-emission is transmitted internal blackbody radiation that is modified by passing through the change in the index of refraction that occurs at the surface-space interface. Polar Heat includes Fresnel and "BRDF" interactions, as well as incoherent scattering, shadowing, obscuration, terrestrial and space emissions and CAD target objects. Multi-bounce and atmospheric transport effects are neglected in the results presented. Initial simulations suggest that polarimetric observations could provide a more sensitive way to detect and identify space objects.