静止气象卫星可见,红外自旋扫描辐射计（VISSR）在轨调焦方法的研究

根据富里叶光学中调制传函数的理分析了ＶＩＳＳＲ成象光学系统的性质，并提出调焦的判据，途径和方法，包括利用快速富里叶变换（ＦＦＴ）对卫星数字云图进行了频谱分析的频谱分析法，对数字云图灰度起伏统计的最大绝对灰度差值和方法，给出了这两种方法的实验和结果，通过接收日本ＧＭＳ－４卫星展宽数字云图的试验表明所介绍的方法可以作为静止气象了卫星ＶＩＳＳＲ在轨调焦的实用方法。其方法及设备并可用于卫星发射前与ＶＩＳＳ

ON THE VISSR FOCUSSING CONTROL OF THE GEOSTATIONARY METEOROLOGICAL SATELLITE ON THE ORBIT

Basing on the theory of MTF ( Modulation Transfer Function) in Fourier optics,the features of VISSR optical imaging system have been analyzed,and a criterion and two methods for VISSR focussig have been provided. They included the frequency analysis method by using FFT (Fast Fourier Transfer )and the method of the sum of maximum absolute value of pixels gray difference using the statistics of the fluctuation of the pixels gray levels for satellite digitalimage data. The experimental processes and results of two methods have been given through receiving stretcher digital images from the Japans GMS-4 satellite. The simulated tests show that these methods developed in this paper would be useful and practical for VISSR focussing control on the orbit. These methods can also be used in the interaface experiment between its equipments and VISSR before the satellite launching.