Calibration of multispectral polarimeter and its measurements of atmospheric aerosols

PSR-1000 is a portable multispectral polarimeter which measures direct solar radiation and sky radiation at the same wavelength bands as a ADEOS/POLDER sensor. A calibration of our PSR-1000 was done based on Langley plot method involving gaseous absorption from October 27 to November 2 in 1997 at Mt. Mauna Kea in Hawaii Island. Then observations with the PSR-1000 were undertaken over the Seto Inland Sea of Japan in 1997, 1998 and 1999. This work describes a procedure to determine the calibration constants of PSR-1000 and an algorithm to retrieve aerosol characteristics from the polarization measurements of sky light.