Single Ccd Quad-band Spectral Imager Calibration And Image Correction

In order to meet the needs of certain remote sensing(RS) applications, some researchers demand to design a kind of planar array digital camera with less bands, which maintains some advantages of high spectral resolution and abilities to identify features withal the planar array camera's strong points of high spatial resolution and geometric properties. In addition, there are strict restrictions for the earth observation on the size and weight of the load on the light RS platforms as unmanned aerial vehicles, airships, tethered balloons, etc.. Funded by related projects and under the demanding background, Institute of Remote Sensing Applications, Chinese Academy of Sciences(IRSA/CAS) and Demonstration Center for Spaceborne Remote Sensing, National Space Administration(DCSRS/CNSA) developed the experimental four-band single-CCD prototype imager.This thesis analysed and summarized the significance and background to develop the experimental four-band single-CCD prototype imager, introduced the overall design and implementations for the prototype imager system and mainly accomplished calibration and image correction for the system.Carried through the system-level laboratory radiometric calibration, including stability, repeatability, homogeneity, dark current and linearity tests as well as relative spectral response and absolute radiometric calibration. To process and construe experimental data, the author analysed the stability of each parameter on different imager states and the changes of imager gains and exposure time and worked out absolute radiometric calibration coefficients for CCD imager on different gains and exposure time. Through simulation to the radiation explored by aviation in natural condition, the author reseted the imager band gain and exposure time. In order to obtain reliability and universality of calibration coefficients, the author brought forward the method of multipoint absolute radiometric calibration to validate the calibration coefficients on different gains and exposure time. Also compiled program for image data radiometric correction pre-processing.Progressed geometric calibration for the four-band single-CCD imager consulting cameras or vidicons' calibration methods in photogrammetry industry. This thesis also introduced specific processes of system geometric calibration and correction experimentation. The results showed that radial distortion coefficient K1 correction was better since the imager system gained original images with the lens distortion coefficients, which utilized two methods to check the camera calibration results.The author analysed and compared the results based on pre-processing of radiometric correction for original images that monitored the Qingdao sea grass disaster by aerial RS and gained from the four-band single-CCD imager.