多TDICCD拼接遥感相机成像串扰分析与抑制

Abstract

In order to solve the imaging crosstalk between charge coupled device (CCD) channels and improve the signal-to-noise ratio (SNR) and imaging quality of multi time delay integration (TDI) charge coupled device mosaic remote sensing camera, a mathematical model of imaging crosstalk is established based on Fourier series analysis of the periodic signal. According to the results of mathematical analysis, the root cause of multi-TDICCD imaging crosstalk between different channels is proposed to be the unsynchronized TDICCD imaging circuit working, which causes high-frequency disturbance on the power ground plane and eventually affects the effective video signals acquisition of neighboring TDICCD. Referring to practical project, isolated CCD power supply, shared unified system clock and other methods are adopted to optimize multi-TDICCD imaging circuit system to suppress the occurrence of imaging crosstalk. The imaging quality and SNR are tested after improvement. Experimental results indicate that the adopted methods which can prevent the occurrence on imaging crosstalk between different CCD channels are effective, and the SNR is improved significantly. When the radiance is 42.6 W/(m2Sr), the camera SNR increases 18.85 dB, reaching to 50.42 dB. The image quality of outside scene imaging is also improved significantly, which can meet the requirements of practical engineering of TDICCD remote sensing camera.