National Satellite Meteorological Center,National Satellite Meteorological Center,National Satellite Meteorological Center,National Satellite Meteorological Center
FY-2 Visible and Infrared Spin Scan Radiometer had obviously nonlinear characteristics at low signal. It brought significant biases when using linear calibration in low temperature targets monitoring especially for typhoon targets, which seriously influences FY-2 quantitative application. Nonlinearity of FY-2D infrared detector in window channels was investigated using laboratory calibration measurements and collocation samples based on high-spectral sensor IASI. It was found that nonlinear performance existed both at high and low signal, but impacts at low signal were the most significant. Comparing with laboratory measurements, linear calibration could cause more than 10 K deviations at low temperature. In order to guarantee the quality of calibration results and its stability, nonlinear calibration scheme was applied only in low temperature area. Nonlinear calibration scheme was investigated from its consistency, and also typhoon application. The results indicated nonlinear calibration was stable, and significantly improved calibration accuracy at low temperature, especially in typhoon monitoring which was advanced at least by 7K.
XU Na, CHEN Lin, Hu Xiu-Qing, LU Feng. Nonlinearity of FY-2D infrared detector in thermal window channels and its correction method[J]. Journal of Infrared and Millimeter Waves,2013,32(4):337~343Copy