A Robust Accurate Earthshine Skyshine Reflection Model for Remote Space Objects

The Air Force space situational awareness mission includes characterization, identification and real-time tracking of resident space objects (RSO). Under low-light conditions not dominated by sunshine, detectable RSO signatures result from reflections of upwelling irradiance. These sources, which are important during dawn, dusk and nighttime, include surface emissions, urban lights, aurora, sudden stratospheric warmings and scattering by polar mesospheric clouds. Tracking RSOs under these conditions will considerably expand surveillance opportunities using both satellite and ground-based sensors. Spectral Sciences, Inc. (SSI) will develop a first principles toolkit named Robust and Accurate Earthshine/Skyshine Reflection Models, (RAES-RM) for predicting this upwelling irradiance in the UV, VIS and IR spectral regions. Leveraging current first-principles models developed under this and previous programs, SSI is teaming with Tau Technologies to interface RAES-RM with the Air Force TASAT systems model, and with Surface Optics Corporation for validation data for urban lights and with Boeing Corporation for measurements and validation data against actual RSOs. When validated, the RAES-RM has applications to systems visibility, earth-directed surveillance, atmospheric compensation for imaging commercial satellites and satellite services including telecommunications, weather forecasting, and navigation. BENEFIT: The anticipated benefits of this effort will be the development and validation of models to support systems studies on how to better track and identify resident space objects (RSO). This will be accomplished by having accurate low-light models for RSO signatures that will define target visibility and background clutter under nighttime conditions. A low-light capability will greatly expand the envelope of satellite surveillance. These models will be interfaced with TASAT, an Air Force satellite systems code. When validated, the RAES-RM has applications to systems visibility and earth-directed surveillance. atmospheric compensation for imaging commercial satellites and satellite services including telecommunications, weather forecasting, and navigation.