星载多光谱遥感器太阳定标技术的进展

星载多光谱遥感器的太阳定标器一般选择太阳作为基准光源，通过它将太阳辐射引入星载遥感器并调节到星载遥感器的动态范围内，对星载遥感器进行绝对辐射定标，也可对星载遥感器性能变化进行监测和校正，文章介绍一些最具代表性的星载多光谱遥感器的太阳定标器，并进行了分析，以反映太阳定标技术的现状与发展，目前采用太阳漫射器的星上定标方法可以实现全现场、全孔径、端点到端点的定标。这一方法的严重缺点是漫射器反射比例时间变化。为了解决这一问题，设计一些比辐射计或反射比标定装置来监测漫射器的辐亮度，反射比以及太阳常数，因此这种定标方法是很有前途的。在现代一些先进的星载多光谱遥感器上获得应用，通过对此方法的分析，提出了在太阳漫射器研制中的一些关键技术。

Progress of the Solar Calibration Technique for Space-borne Multispectral Sensors

The solar is selected generally as a standard source on the on board solar calibrator of satellite multispectral sensors. The solar radiation is leaded into the space borne remote sensors and adjusted within the sensor's dynamic range by means of the solar calibrator. It is used to provide absolute radiometric calibration to the sensors and may be used to monitor and correct for possible performance changes of the sensors. Some solar calibrators used for space borne multispectral sensors are introduced and analysed, in order to reflect the present state and development of the solar calibration techniques.At present, the use of a solar diffuser is a desirable approach to the on board absolute radiometric calibration. It provides a full aperture, full field and end to end calibration. A serious drawback is that the diffuser's reflectance may change with time. In order to solve the problem a kind of ratioing radiometer or reflectance calibration assembly used to monitor the radiance and reflectance of the diffuser and solar constant is designed. Now the approach comes into use on some advanced space board multispectral sensors. The paper also puts forward some key techniques during the development of the solar diffuser after analyzing this aproach.