Research On The Data Processing Method Of Range-gated Laser Imaging

Range-gated laser imaging which can be engineered at the present is a non-scanning laser imaging method; It can inhibit the backscattering noise effectively to get high-quality images of target. It can also get the distance information of target, which is significant to the target recognition. We analyzed the noise source of the imaging system, proposed the filtering method for Range-gated laser imaging and the method of assessing image quality of laser active imaging system. Finally we built the range-gated laser imaging system to verify the method of data processing.Firstly, we studied the range-gated laser imaging theory, focusing on the method of target slice imaging. We summarized several generic denoising algorithms, and gave the theoretical basis and process for the different denoising algorithms.Secondly, the noise source of imaging system was analyzed by different methods. In the daytime conditions, we established the SNR model of range-gated laser imaging system, calculated the SNR in both cases of background noise existence and removal to conclude the distribution of the system noise. In the night conditions, we analyzed the statistical characteristics of the noise from range-gated imaging system and compared the result with the statistical characteristics of Speckle noise and Gaussian noise, to conclude which is the main noise of the image. we gave the method of image quality assessment of laser active imaging system, including noise estimation and SNR calculation.Thirdly, according to the previous theoretical analysis, we filtered the laser image noise using several generic denoising algorithms, and analyzed the effect of noise filters by using the method of image quality assessment.Finally, the filtering method for the range-gated laser imaging feature was proposed to filter the background noise. We erected the range-gated imaging system and designed two sets of imaging experiment: multi-pulse imaging and single-pulse imaging. We verify the method of data processing for the range-gated imaging system.