Summary: | Light Detection and Ranging (lidar) technology has been applied in military and civil areas and shows great potential. However, in coherent lidar detection, significant Doppler Effect and velocity uncertainty result a bad influence on moving target ranging. In this study, the authors demonstrate a velocity compensation method based on both Doppler shift evaluation and velocity searching and matching method. The authors used dot-linear frequency modulation signal for detection in order to achieve both velocity and distance information in the same period. Further by using searching and matching processing based on Shannon entropy can give a better-compensated velocity to extract more accurate distance information of targets. The authors applied this method on passive and self-driving moving targets, which fit the actual characteristics of both kinds of targets. Especially in self-driving moving target, there exists a significant target fluctuation in movement during detection that causes the splitting of Doppler peaks. The blurry in velocity estimation restricts the accuracy of sensing. The authors found the Shannon entropy searching method could reduce this effect. On the other hand, the feature of fluctuation in micro movement may give a way to identify the targets in the future.
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