VICARIOUS CALIBRATION ON THE SENSOR OF WHOLE SKY INFRARED CLOUD MEASURING SYSTEM

In order to calibrate the sensor of whole sky infrared cloud measuring system(WSIRCMS) in operational period, a vicarious calibration method was proposed based on the clear sky infrared radiance field. The response rates and the offsets of the whole array were obtained by linear regression methodon the basis of the clear sky infrared radiance modeled by SBDART, and the DN values were observed. Our results show that the uncertainty of the response rates is 2.03DN unit/(W. m(-2) . sr(-1)), and the offsets have a character of normal distribution which can be considered as spatial random noise. The average error of temperature retvieved is within +/- 1.5 degrees C according to the validation of the blackbody test data, which can satisfy the quantitative applications of WSIRCMS.