The Key Technology Research Of Space Staring Imaging With A Large Area Array Image Sensor

Imaging electronics is a key factor which restricts the high temporal resolution andhigh spatial resolution development of earth observation on geostationary orbit. And themain contents of the imaging Electronics are: the development of monolithic large areaarray image sensor, the mosaic image sensor, the high-speed low-noise image acquisition,the large-capacity data transmission and storage, the quantitative testing of large area arrayand high-resolution imaging system, etc. Around these points, the main contents of thisarticle are as follows.Fristly, under the fully understand of the observed target characteristics, there are a lotof work have been done on the image sensor design,especially these key parameters such asthe number of pixels, pixel size, the number of noise electrons, full well electrons, etc. Atthe same time completed the imaging channels accurate modeling which based on theselected imaging modalities and image data transmission link. This model provides atheoretical support for the system quantitative analysis.Secondly, a principle prototype has been designed whose image sensor is a CMOS12800×12800, latest design by the Chinese Academy of Sciences. Under the requirementsof50m resolution in geostationary orbit,1280km×1280km image area, we need a25600×25600CMOS image sensor to achieve this goal. That means it needs at least for12800×12800image sensors to mosaic. But at now, we do not have enough12800×12800imagesensors, so we chose2560×2560image sensors as an alternative to make a principleverification.Thirdly, after completed the prototype design, based on the actual requirements ofscientific applications, to make a detailed quantitative analysis of the prototype systembecomes inevitable. The main contents of the quantitative analysis include three aspects.They are the geometric parameters analysis of the mosaic image sensor, the high-speedlow-noise image data acquisition system quantitative analysis and the responsecharacteristics of the image sensor quantitative analysis. The results of the image sensorsand the camera systems quantitative analysis show that both these two meet therequirements of the default indicators. These good results provide a strong support for thefuture research.In a more specific aspect, for the geometric parameters analysis of the mosaic image sensor, we have propose a comprehensive testing program which based on visible Imaging,and the result is similar to the dedicated instrument. At the same time for the sub-samplingproblem happened on the pixel time noise test which is more obvious when the area array ismuch greater, we have done a comprehensive theoretical analysis. Proved that thesub-sampling does not influence the time noise test result, it just only influences the noisespectral characteristics. So it can be ignored during actual testing steps.