Time delay estimation-based laser ranging method

Abstract

The invention discloses a time delay estimation-based laser ranging method, which is used for ranging through the time difference between an echo signal and a transmitted signal. The method comprises the following steps of: (a) acquiring the transmitted signal and the echo signal; (b) performing time delay estimation according to the transmitted signal and the echo signal to obtain a time delay estimation value; and (c) adding the time delay estimation value to the echo signal to obtain the distance which needs to be measured and calculated. According to the laser ranging method provided by the invention, the time delay of the echo signal with low signal-to-noise ratio relative to the transmitted signal is directly obtained from continuous modulated laser signals by adopting a time delay estimation technology. According to the laser ranging method provided by the invention, the laser ranging is performed by a robustness-based time delay estimation algorithm, a noise signal is modeled by Alpha stable distribution, and the time delay between the echo signal and the transmitted signal is solved by adopting a fractional lower order covariance function and related functions.

Description

technical field [0001] The invention relates to the field of laser ranging, in particular to a laser ranging method based on time delay estimation. Background technique [0002] The meaning of laser is stimulated radiation light amplification, which is an artificial light. Compared with ordinary natural light sources, laser has the characteristics of high directivity, monochromaticity and high coherence. These excellent characteristics of laser make it used in many fields, among which the use of laser to measure distance is one of the important practical applications of laser, and lidar is based on laser to detect and measure distance. [0003] The signal of laser ranging can be in pulse state or in continuous wave state. Usually, the former is called pulsed laser ranging and the latter is called phase laser ranging. Pulse laser ranging is that a laser transmitter emits a pulsed laser signal to the target, the signal is reflected and received by the receiver, and the time i...

AI Technical Summary

Problems solved by technology

The method of phase laser ranging to improve the accuracy often requires a higher signal-to-noise ratio of the echo signal. If the echo signal is submerged in the noise, it is difficult to obtain the phase delay information.

In addition, in practice, the laser ranging echo signal often contains impulsive noise, which will degrade the performance of the traditional calculation method based on the Gaussian noise model, and even make it impossible to use

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