OPIR Radiometric Calibration

The Air Force is exploring alternative uses for Overhead Persistent Infrared Missile Warning (OPIR-MW) systems, which require improved on-orbit sensor radiometric calibrations. These systems are heavily tasked by their primary mission, so calibration must be accomplished without additional tasking or ground support. Spectral Sciences, Inc. proposes an innovative calibration scheme based on cross calibration of the OPIR data stream with contemporaneous measurements from the geostationary operational environmental satellites and Japanese Himawari weather imaging satellites, which collectively provide continuous, high quality radiometrically-calibrated imagery with exceptional Earth coverage. In Phase I, we employed novel real-time bidirectional ground reflectance models with optimized spectral band fitting to generate accurate calibration constants for OPIR spectral bands. These proposed innovations will simplify using advanced simulations, improve accuracy by accounting for variable reflectance, and work for all OPIR wavebands, including those with strong atmospheric absorption features. The Phase I proof-of-concept clearly demonstrated this procedure for imaging systems with OPIR equivalent bands. In Phase II, we will develop the REmote Sensing Precise ON-orbit SEnsor calibration (RESPONSE) software toolkit to provide general capability for satellite sensor calibration and conduct comprehensive testing and analysis focused on using live data sources in an operational-like environment.