Research On The Ranging Accuracy Of Digital Full-waveform Lidar

Compared with traditional analog signal processing,digital full-waveform Lidar can use more flexible signal processing methods to acquire target distance and surface shape features by digital signal processing of laser echo,to achieve better ranging accuracy is an important direction in the development of laser radar.In this paper,the analysis method of range accuracy of digital full-waveform Lidar and its application to range of different surface targets are studied,the aim of this paper is to provide the basis for the optimal design and application of digital full-waveform Lidar system.On the basis of in-depth data investigation,the principle of laser radar ranging,the system composition and ranging process of digital full-waveform laser radar,and the digital full-waveform expression of laser radar echo signal are presented,the influence of sampling and quantization on laser echo signal is discussed.By introducing the concept of quantization noise and the theory of lower bound of cramer-rao,the limit formula of ranging accuracy for digital full-waveform Lidar is derived The simulation model of digital full-waveform Lidar ranging process is established,and the effects of sampling and quantization on ranging results and ranging accuracy are studied by computer simulation,if the signal amplitude is 1V,the500 MHz sampling rate and 6 bit A/D are used to sample and quantify the waveform,so the influence of sampling and quantization on ranging accuracy can be ignored.The paper also deduces the expression of probability density distribution of digital full-waveform Lidar ranging data when the ranging object is plane,cone,sphere and paraboloid,the effects of surface parameters such as cone apex angle,spherical radius and paraboloid shape coefficient on the ranging accuracy of Lidar are calculated and discussed,the ranging accuracy of Lidar can be improved by increasing cone apex angle,spherical radius and paraboloid shape coefficient.In addition,a digital full-waveform Lidar experiment device is set up,and the effects of sampling and quantization parameters,as well as the surface parameters of the target on the ranging accuracy of the digital full-waveform Lidar are studied experimentally,the correctness of the theoretical result is verified.