Comparison of line-by-line and molecular band IR modeling of high altitude missile plume

This paper deals with the quantitative comparison of modeling IR radiation emitted from the plume of a tactical ballistic missile (TBM) in the boost phase with two different model approaches. IR spectra of the missile plume are calculated both with the high spectral resolution line-by-line radiation model FASCODE 3 (fast atmospheric signature code) using the databases HITEMP or HITRAN and the low spectral resolution IR radiation model NIRATAM (NATO InfraRed Air TArget Model) using molecular band model technique. The influence of the atmosphere on the IR spectra as viewed from a space born sensor is taken into account. The results show, that using an elaborate line-by-line radiation model can improve the accuracy in computation of IR signature compared to the simpler but faster molecular band model technique used in NIRATAM.