Environmental Monitoring By Fourier Transform Infrared Spectrometry PDF Download

This paper surveyed four potential military uses for a Fourier Transform Infrared (FTIR) Spectrometer. A physical method to retrieve vertical atmospheric temperature profiles using a least-squares solution on atmospheric radiance observed at the surface in the 4.3-micrometer carbon dioxide absorption band was analyzed. The method was not successful. Weighting functions, calculated from the surface looking up, were a maximum at the surface, so no unique solution for temperature retrieval by height was determined. Observed atmospheric radiance measurements were compared with radiance calculated using the Moderate Resolution Transmittance Code (MODTRAN). Qualitative comparison showed spectral features of observed and calculated radiance plots matched exceptionally well. The utility of the FTIR spectrometer for environmental monitoring was demonstrated by identifying CO2, CO, O3, HCl, SO2, and N2O emissions from a coal-burning plant smokestack. An FTIR spectrometer was used to collect data of controlled detonations of statically displayed Mk 82, Mk 83, and Mk 84 bombs; High-speed Anti-Radiant Missiles (HARM); Tomahawk Land-Attack Missiles (TLAM); and C-4 plastic explosive over the 1800-6000 /cm spectral band at 16 /cm resolution. Results showed there were unique spectral features associated with some warhead types.