Bidirectional Reflectance Factors used in Lidar Calibration

Many atmospheric remote sensing applications of infrared lidar systems require that the backscatter signal be radiometrically calibrated. These systems are usually monostatic, consequently the reflected radiance from hard targets used in calibration will include the diffuse and the retroreflectance characteristics of the material. Radiometers which are part of orbiting sensors frequently contain onboard calibration subsystems. The onboard calibrator often utilizes onboard reflectance panels which are deployed at particular orbital locations to use the reflected sun light to calibrate the radiometers. To meet the need for correlative calibration of these remote sensing techniques a physically derived model could be used to extend the angular range and to improve the angular resolution of the measured reflectance properties of the calibration materials. A modified version of the B. Hake and E. Wells model has been adapted and will be described.