Computation of Highly Excited Molecular Spectra

"Radiation-transport (RT) codes constitute the core component of the target, plume, background, and atmospheric signature models utilized by BMDO and virtually every other government agency and commercial company involved in developing optically-basedweapons, surveillance, and remote sensing systems. Critical to the accuracy and range of application of the RT codes are the accuracy and completeness of their companion molecular spectral properties databases, e.g., HITRAN, HITEMP, SIRRM. These databasesare incomplete and in many spectral regions are of insufficient accuracy for many applications. To address this problem Spectral Sciences, Inc. proposes a new spectral parameter modeling approach, merging measurements and ab-initio generated data to form acomplete and seamless spectral database, dubbed CHEMS (Computation of Highly Excited Molecular Spectra). In CHEMS, the high spectral line density found at high temperature is described at much lower spectral resolutions, taking advantage of a classicaldynamics-based approach. In Phase I, we will demonstrate the CHEMS approach by application to CO2 for which good high-temperature lines, potential surface, and dipole moment functions are available. In Phase II, we plan to implement a general version ofCHEMS integrated with a line generation approach, resulting in a complete spectral database generation capability. CHEMS will address both military and commercial market needs that require th