Interferometric Imaging Technology for Passive Microwave Radiometry
干涉式被动微波成像技术

Recently,applications from atmosphere,ocean and land soil moisture have required higher and higher spatial resolution for passive microwave remote sensors.However,if we use the conventional technology,once the spatial resolution reaches a certain level,the small resolution cell will limit the sensitivity of the brightness temperature measurement due to very short integration time at each of the cell.In this paper,a new technology,so called interferometric radiometry or synthetic aperture radiometry,is summarized.While the basic principle is introduced,the authors tried to explain it in a different way from the point of view that every target or distributed scene has characters in their frequency domain pictures.What the new technology does is,in fact,not to measure the scene in its original spatial domain but to measure it in its frequency domain by a sampling device called two-element interferometer.From this point of view,the new technology appears more systematic and clear to understand.While the imaging systems are summarized,the authors emphasize more on the 2-D clock rotation sampling system with associated image retrieval algorithm,called the Pseudo Polar Grid Method,which both were developed by the authors.