High-precision Centroid Extraction and PSF Calculation on Remote Sensing Image of Point Source Array

The high-precision measurement of remote sensing image geometric and radiometric information is an important basis for remote sensing image geometric and radiometric processing. Based on the theory of image degradation, this paper describes the method of obtaining simulated degradation image of point source array using prior information. Then the shortcomings of traditional Point Spread Function (PSF) parameter solving methods are analyzed, and a new algorithm for PSF parameter solving is proposed on this basis. Experimental results show that the accuracy of geometric center of point source and full-width half-maximum width (FWHM) of PSF obtained by the proposed method from simulated degradation image are better than the traditional algorithms. When the SNR is 40dB, the RMSE of the geometrical position of the point source obtained by proposed algorithm is only 0.01 pixels; the RMSE of FWHM of PSF is only 0.03 pixels. Experimental results further show that the use of the multiphase point source arrays can effectively improve the accuracy of PSF parameter. This paper demonstrates that point source can provide both high precision geometry and radiation information for remote sensing images, and will potentially be an ideal tool for joint geometric and radiometric calibration.