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Macau Periodical Index (澳門期刊論文索引)
- Author
- Li, Zhi; Cai, Zhanchuan; Tang, Zesheng
- Title
- Calibration of location coordinates in Chang'E-2 CCD data
- Journal Name
- 澳門科技大學學報
- Pub. Info
- Jun. 2015, Vol.9, No.1, pp. 117-124
- Link
- http://lib.must.edu.mo/sites/default/files/assets/images/Duu/must_journal_201501.pdf
- Keyword
- Chang'E-2；CCD images；Coordinates calibration；Image registraion
- Abstract
- Abstract : The CCD stereo camera of Chang'E-2 satellite produces the high spatial resolution images. However, the positioning precision is low. The coordinates of corresponding points in the adjacent orbits of 2C level CCD images exist considerable difference. Combining with the image registration technique and the characteristic of Chang'E-2 CCD images, a method of calibration the longitude and latitude coordinates is proposed in this paper. Firstly, feature points of reference image is extracted by Harris detector. Secondly, the overlapped region between reference image and target image is obtained by the normalized cross-correlation method. Next, in the overlapped region, the corresponding point pairs are established by area-based registration. Lastly, the coordinates of target image have been calibrated by means of the transformation matrix (it is computed by the corresponding pairs' coordinates). The proposed method can decrease the relative positioning error, improve location accuracy and solve the contradiction (CCD image of high spatial resolution and the location coordinates of low positioning accuracy) to prepare the mosaic of lunar images. Paragraph headings: 1. Introduction 2. CCD Image Data of Chang'E-2 2.1. CCD Stereo Camera 2.2. CCD Data Formation 3. Calibration Algorithm of Longitude and Latitude Coordinates 3.1. Feature Point Detection 3.2. Feature Points Matching 3.3. Transformation Matrix 3.4. Calibration of Longitude and Latitude Coordinates in Target Image 4. Experiment Results and Analysis 4.1. Implementation 4.2. Analysis 5. Conclusion and Discussion Tables: 1. Technical index of CCD camera Figures: 1. Imaging Principle of the CCD stereo camera 2. Illustration of the CCD data 3. Area-based registration 4. Feature point matching 5. The transformation matrix solving 6. Calibrated longitude and latitude coordinates of target image 7. CCD images' coordinates 8. The result of CCD images reconstruction from their original coordinates 9. The overlapped region 10. The correspondent point pairs 11. The correspondent point pairs of the target image coordinates and the reference image coordinates after calibration: (top) whole graph and (bottom) graph of zooming in 12. The target image coordinates after calibration 13. The reconstructed image by the calibrated coordinates 14. Comparison of the reconstructed image (1st-3000th rows): (top) according the original coordinates and (bottom) by the calibrated coordinates 15. The reconstructed image of three adjacent orbits (1st-500th rows) by the calibrated coordinates 16. Pie chart for corresponding pairs errors statistics (1st-3000th rows of 301th orbit and 302th orbit)