Research On Techniques For On-Orbit Geometric Calibration Of Space Linear CCD Sensors

The high-resolution satellite remote sensing images have played an important role in the national defense and economic construction. China has also launched a series of remote-sensing satellites and obtained abundant images, but the utilization of domestic satellite remote sensing images keeps at a low level, mainly due to the not so high positioning accuracy. Though the strict geometric model of linear CCD satellite remote sensing images, ie the collinearity equations, has a high positioning accuracy, but it is set up in an ideal circumstances. In the satellites launching and running process, various diversiform reasons will make CCD and lens parameters change, the prior model will be no longer appropriate. It demands on-orbit geometric calibrating for the changed parameters in order to improve the geometric quality. This paper does a preliminary study about on-orbit geometric calibration. The main works completed in the thesis are listed as follows.1. The significance and background of the research is described, the status domestic and foreign quo of on-orbit geometric calibration study is introduced.2. A series of coordinates and corresponding coordinates transformation is introduced ,a strict image model is built, and the basic theory of forward intersection is described.3. After analyzing rules of SPOT5 HRS images'ephemeris and attitude, the detection model is established for the constant angular error in exterior orientation elements. The elements of interior orientation is modeled and optimized,the every parameter's impact on the pixel offset is also analyzed. The orientation elements'impact on the positioning accuracy is deduced.4. Referring the SPOT5 HRS imaging mode ,geometric data is simulated which have the nearly real conditions. The single-image space resection and bundle adjustment are used to calibrate the space of linear CCD sensor respectively, then a comparison is made between results.5. The relationship between the CCD chips is calibrated utilizing ALOS images. The method calibrating the angle between the cameras is derived and validated using simulated data.6. Summing up the results of this research and pointing problems continuing to research.