Research On Laser Radar Target Information Extraction Method Based On Digital Full Waveform

The echo waveform received by the LiDAR is the signal obtained from the interaction between the laser and the transmission medium and the target, it contains abundant target information. The Full-waveform technology is the key to extract the target information from the echo signal, in this way we can get richer target features than traditional distance measurement. So this paper concentrate on the echo signal characteristics and the extraction of target information from digital full-waveform LiDAR, and the theoretical simulation and experimental research are carried out.In order to study the distance, angle and other information extraction methods, This paper use the beam model of the transmitted pulse laser as bases, established the mathematical model of the influence of the target characteristic on the echo signal under the Gauss distribution, analyses the influence of common target features such as inclined surface, right angle target and multiple target to the echo waveform, and carried out the simulation research. Then this paper come to the conclusion that if the target is incline, the echo wave will be wider, if the targets is not on a plane, the echo wave will be divided to several waves., if the target has two sides, the echo wave will be plus by two different waves, and so on. I programmed in the software of matlab with the algorithm of LM and use the program to decompose the simulation data. According to simulation and experimental verification, the algorithm of LM is able to extract the distance information between multiple target. When the pulse width is 20ns, the divergence angle is 5mrad, the minimum target distance is 2.2 meters, and the error is less than 5%. When the target distance is less than 2.2 meters, we can judge the distance according to the echo stretching. In this paper, the change characteristics of the echo of the laser radar in the scanning target are also studied. At last I compared the extracted information with the real targets information, verified the reliability of the extraction method.