LADAR Performance Simulations with a High Spectral Resolution Atmospheric Transmittance and Radiance Model- LEEDR

In this study of atmospheric effects on Geiger Mode laser ranging and detection (LADAR), the parameter space is explored primarily using the Air Force Institute of Technology Center for Directed Energy\u27s (AFIT/CDE) Laser Environmental Effects Definition and Reference (LEEDR) code. The LADAR system is assessed at operationally representative wavelengths of 1.064, 1.56 and 2.039 μm with several up and down looking engagement geometries at locations worldwide. Results computed with LEEDR are compared to standard atmosphere and Fast Atmospheric Signature Code (FASCODE) assessments. Results show significant climate dependence, but large variances between climatological and standard atmosphere assessments. An overall average absolute mean difference ratio of 1.03 is found when climatological signal to noise ratios at forty locations are compared to their equivalent standard atmosphere assessment. Atmospheric transmission is shown to not always correlate with signal to noise ratios between different atmosphere profiles. Allowing aerosols to swell with relative humidity proves to be significant especially for up looking geometries reducing the signal to noise ratio several orders of magnitude. Turbulence blurring shows that the up looking LADAR system has little capability at a 50km range yet has little impact at a 3km range