Development and testing of the target for radiometric calibration of spaceborne remote sensing science instruments

The method for on board calibration of the space imaging instruments using a diffusing target illuminated by the sun radiation is gaining acceptance. This raises a problem of measurements of the spectral and angular response of the target reflectivity in illumination conditions similar to the actual one on-board. This work summarizes the progress in the development and testing of the target for on-board radiometric calibration of the space video-spectrometers in stereo- spectral imaging system ARGUS. The spectral and angular response of the target reflectivity and the experimental procedure used for getting these characteristics are described. The target manufacturing technique is described. This target was tested for the spectral properties from 0.3 micrometers to 5.2 micrometers at angle of illumination -70 degree(s) (relative to the normal of the target) and angle of viewing +20 degree(s). The angular response was measured with three incident angles 70 degree(s), 75 degree(s) and 80 degree(s) (relative to the normal) for angles of viewing varying between 0 degree(s) and 60 degree(s) (relative to the normal). Brief description of the setup for measurements of the spectral and angular response of the target reflectivity are presented. The values of angular and spectral response of the reflectivity have been determined with the accuracy of 2 - 5% depending on the wavelength.