Multi-channel laser radar ultra-shallow water sounding data processing method

Abstract

The invention discloses a multichannel laser radar ultra-shallow water sounding data processing method and belongs to the field of laser radar underwater surveying and mapping. The method comprises the steps of: obtaining the mean value and variance of echo-free waveform data of a shallow water channel of a multichannel laser radar and adopting the mean value and variance as a mean value referencevalue and a variance reference value respectively; subtracting the mean reference value from the echo waveform data of the shallow water channel, and extracting data of which the duration Tns (T>0) is greater than the variance reference value as effective echo data; gaussian fitting is carried out on the effective echo data to obtain a first fitting curve, and seabed echo relative time T1 is determined according to the first fitting curve; Gaussian fitting is carried out on the difference value between the effective echo data and a first fitting curve to obtain a second fitting curve, and seasurface echo relative time T2 is determined according to the second fitting curve; and the water depth H of an ultra-shallow water area is calculated according to an equation that H=v*(T2-T1). According to the method, the actual water depth of the ultra-shallow water area can be accurately calculated by using the sounding data of the multi-channel laser radar, and the calculation speed is effectively increased.

Description

technical field [0001] The invention belongs to the field of laser radar underwater surveying and mapping, and more specifically relates to a multi-channel laser radar extremely shallow water sounding data processing method. Background technique [0002] Lidar has the characteristics of strong energy, good directionality, short wavelength, and high resolution. It has played an important role in the application field of marine topographic mapping, especially in shallow water areas near coastal zones and islands and reefs. [0003] Due to the strong attenuation of laser energy by seawater, the dynamic range of the underwater echo signal received by the lidar is very large. While detecting the weak signal in deep water, its sea surface and shallow water echo signals are very easy to cause saturation of the detector. . For this reason, in order to expand the detection dynamic range in the actual laser radar sounding system, the sounding echo adopts two channels of shallow water...

AI Technical Summary

Problems solved by technology

This method can calculate the actual water depth in extremely shallow waters, but it takes a long time in the iterative process and cannot be applied to applications with high real-time requirements

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