Improved Velocity Estimation Method for Doppler Sonar Based on Accuracy Evaluation and Selection

Abstract

The matched filtering method and the waveform-tracking method cannot maintain optimal velocity estimation performance all of the time. In order to solve this problem, this paper proposes an improved velocity estimation method for Doppler sonar, based on accuracy evaluation and selection. The echo of Doppler sonar is divided into several segments with the same width as the transmitted pulse, and each segment is regarded as the echo of the corresponding water layer. According to our study’s results, the velocity estimation accuracy of each segment is positively correlated with the ratio of its autocorrelation modulus to its power. Based on this conclusion, a velocity accuracy criterion with high accuracy and low complexity is designed in order to select the optimal velocity estimation for water layers or bottoms. The proposed accuracy selection method flexibly selects the echo interval to be processed according to the accuracy criterion, so as to maintain the optimal estimation of the current’s or bottom’s velocity. Water tank and field experiments using a prototype Doppler sonar device demonstrates that, compared with the matched filtering method and the waveform-tracking method, the average velocity estimation accuracy and bias of the proposed method are superior.

VCH: A Velocity Measurement Method Combining HFM Signals

“…The matching filtering method and waveform tracking method cannot always maintain the best speed estimation performance. To solve this problem, an improved Doppler sonar velocity estimation method based on accuracy evaluation and selection is proposed (Yang and Fang [19]). The Doppler sonar echo is divided into segments of the same width as the emitted pulse, and each segment is treated as an echo corresponding to the water layer.…”

Motion parameter estimation of AUV based on underwater acoustic Doppler frequency measured by single hydrophone

“…In recent years, the characteristics of active Doppler sonar have been applied to estimate the velocity by accurately estimating the Doppler frequency (Yang and Fang, 2021;Saffari et al, 2022). Further, hydrophones have been used to estimate the motion information of aerial sound sources.…”