DIRECTIONAL-HEMISPHERICAL REFLECTANCE FOR SPECTRALON BY INTEGRATION OF ITS BIDIRECTIONAL REFLECTANCE

The directional-hemispherical reflectance is obtained for Spectralon, the material chosen for onboard radiometric calibration of the multian gle imaging spectroradiometer, at laser wavelengths of 442, 632.8, and 859.9 nm. With p-and s-polarized incident light and for an angle of i ncidence of 45 degrees, the bidirectional reflectance distribution fun ction was measured over a polar angle range of 1-85 degrees and a rang e of azimuthal angles of 0-180 degrees in 10 degrees increments. The r esultant directional-hemispherical reflectance is found by integration to be 1.00 +/- 0.01 at 442 nm, 0.953 +/- 0.01 at 632.8 nn, and 0.956 +/- 0.01 at 859.9 nm. The experimental methodology and the data analys is are presented together with a full discussion of the primary experi mental errors. (C) 1998 Optical Society of America.