kURT, k-distribution based Ultra-fast Radiation Transport

Design of electro-optical sensors for military and commercial use increasingly relies on scenario simulation models. It is critical these models yield accurate transmittances and at-sensor radiances, and be extremely computationally fast to allow robust sampling of the multi-dimensional design parameter space. Spectral Sciences, Inc. proposes to develop a sensor bandpass tailored RT model, dubbed kURT (k-distribution based Ultra-fast Radiative-Transfer). kURT features a new and innovative method for combining fine spectrally gridded MODTRAN4 k-distributions into a compact and accurate k-distribution for an entire and spectrally-broad sensor bandpass. This provides bandpass transmittance and radiance calculations that are faster by a factor of 100 or greater than MODTRAN4. In Phase I, MODTRAN-generated k-distribution databases will be created for 3-5 micron and kURT modules developed for generation of sensor band k-distributions and prediction of ultra-fast transmittances. These results will be compared to integrated 1 cm-1 MODTRAN4 predictions to determine if kURT meets the requirement for agreement to within 2% in transmittance. In Phase II, the kURT spectral range will be extended for UV through LWIR applications, and the kURT approach generalized for calculation of thermal and solar radiances.