Rapid Multiple-Scattering Radiative Transfer Algorithm for Target Acquisition Weapons Software

Scene simulations are increasingly used for electro-optical sensor design, performance evaluation, and data analysis over a wide range of environment and engagement conditions. For Army ground-to-ground scenarios, Target Acquisition Weapons Software (TAWS) is used to determine target-to-background contrast for optical bandpasses over many lines-of-sight (LOS’s). The present 2-stream multiple scattering (MS) method used in TAWS is insufficiently accurate for computing critical horizontal and near-horizontal LOS radiances. Spectral Sciences, Inc. (SSI) has demonstrated a new radiation transport capability, combining an efficient multiple-LOS MS algorithm with a broad-bandpass correlated-k methodology (called kURT), which provides orders-of-magnitude improvement in computation speed and accuracy compared to existing methods. SSI hereby proposes a Phase II continuation of this R&D to develop and deliver a complete package of kURT-MS software routines to be run from TAWS as well as from other computer codes. In addition, we anticipate releasing a new version of MODTRAN that runs the kURT-MS algorithms, making their powerful capabilities available to the broad community of MODTRAN users. SSI will be assisted by Research Systems Inc. and SciTec, Inc.