MODTRAN4: multiple scattering and bidirectional reflectance distribution function (BRDF) upgrades to MODTRAN

Prabhat K. Acharya; Alexander Berk; Gail P. Anderson; George P. Anderson; North F. Larsen; Si Chee Tsay; Knut H. Stamnes

doi:10.1117/12.366389

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20 October 1999 MODTRAN4: multiple scattering and bidirectional reflectance distribution function (BRDF) upgrades to MODTRAN

Prabhat K. Acharya, Alexander Berk, Gail P. Anderson, George P. Anderson, North F. Larsen, Si Chee Tsay, Knut H. Stamnes

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Proceedings Volume 3756, Optical Spectroscopic Techniques and Instrumentation for Atmospheric and Space Research III; (1999) https://doi.org/10.1117/12.366389
Event: SPIE's International Symposium on Optical Science, Engineering, and Instrumentation, 1999, Denver, CO, United States

Abstract

Radiance multiply scattered from clouds and thick aerosols is a significant component in the short wave IR through the visible region of the electro-optical (EO) spectrum. In MODTRAN, until very recently, multiple scattering predictions could not vary with the azimuth of the line-of-sight (LOS), although the single scattering component of the radiance did take the azimuthal variation into account. MODTRAN has now been upgraded to incorporate the dependence of multiple scattering (MS) on the azimuth of the LOS. This was accomplished by upgrading the interface between MODTRAN and DISORT, which is used as an MS subroutine in MODTRAN. Results from the upgraded MODTRAN are compared against measurements of radiance in a cloudy sky in the 1.5 - 2.5 micrometer region. Furthermore, taking advantage of DISORT, the upgraded version of MODTRAN can accommodate parameterized BRDFs (Bi-Directional Reflectance Distribution Functions) for surfaces. Some results, which demonstrate the new MODTRAN capabilities, are presented. Additionally, MS results from MODTRAN are compared to results obtained from a Monte-Carlo model.

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Prabhat K. Acharya, Alexander Berk, Gail P. Anderson, George P. Anderson, North F. Larsen, Si Chee Tsay, and Knut H. Stamnes "MODTRAN4: multiple scattering and bidirectional reflectance distribution function (BRDF) upgrades to MODTRAN", Proc. SPIE 3756, Optical Spectroscopic Techniques and Instrumentation for Atmospheric and Space Research III, (20 October 1999); https://doi.org/10.1117/12.366389

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