FY-3A气象卫星红外分光计温度廓线模拟反演试验

为了考察风云三号(FY-3)气象卫星红外分光计的性能, 以该仪器初样阶段的光谱通道特征和仪器响应函数为基础, 进行大气温度垂直廓线模拟反演。选用红外分光计15 μmCO₂吸收带的不同通道组合进行模拟反演, 结果表明:总体上红外分光计具有较好的大气温度反演能力, 窗区通道8的加入可有效提高近地面层温度反演精度;利用迭代算法反演大气温度时, 初估廓线对反演精度影响较大, 初估廓线与真值愈接近, 反演精度愈高;现有仪器通道灵敏度设计指标可满足大气温度反演基本要求, 如仪器灵敏度降低, 反演精度也随之降低, 提高仪器灵敏度, 有利于提高仪器的使用效果。

Experiments with Atmospheric Temperature Profile Retrieval from FY-3A Iras Soundings

To investigate the performance of InfRared Atmospheric Sounder (IRAS)aboard the satellite FY-3A, the retrieval of the vertical profile of atmospheric temperature is studied based upon the IRAS channel spectral characteristics in i ts initial design and the spectral response function of the spectrometer.The retrieval is performed using different combinations of channels for 15 μm CO₂absorption bands of the IRAS, indicating that on the w hole the sounder produces higher retrieval and inclusion of channel 8 leads to the remarkable improvement of retrieval precision of near-surface-layer temperature.For the retrieval from an iterative algorithm the first guess profile affects the precision greatly, and the closer the estimated profile to the t rue value, the higher the accuracy.The designed channel sensitivity meets the required needs of such retrieval.Low sensitivity leads to lowered precision.As a result, the retrieval precision depends strongly on the IRAS sensitivity.