Estimating the delay-Doppler of target echo in a high clutter underwater environment using wideband linear chirp signals: Evaluation of performance with experimental data

Ge Yu; T C Yang; Shengchun Piao

doi:10.1121/1.5005888

Estimating the delay-Doppler of target echo in a high clutter underwater environment using wideband linear chirp signals: Evaluation of performance with experimental data

J Acoust Soc Am. 2017 Oct;142(4):2047. doi: 10.1121/1.5005888.

Authors

Ge Yu¹, T C Yang², Shengchun Piao¹

Affiliations

¹ Acoustic Science and Technology Laboratory, College of Underwater Acoustic Engineering, Harbin Engineering University, Harbin, 150001, China.
² College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, 310058, China.

PMID: 29092561
DOI: 10.1121/1.5005888

Abstract

A chirp signal is a signal with linearly varying instantaneous frequency over the signal bandwidth, also known as a linear frequency modulated (LFM) signal. It is widely used in communication, radar, active sonar, and other applications due to its Doppler tolerance property in signal detection using the matched filter (MF) processing. Modern sonar uses high-gain, wideband signals to improve the signal to reverberation ratio. High gain implies a high product of the signal bandwidth and duration. However, wideband and/or long duration LFM signals are no longer Doppler tolerant. The shortcoming of the standard MF processing is loss of performance, and bias in range estimation. This paper uses the wideband ambiguity function and the fractional Fourier transform method to estimate the target velocity and restore the performance. Target velocity or Doppler provides a clue for differentiating the target from the background reverberation and clutter. The methods are applied to simulated and experimental data.

Publication types

Research Support, Non-U.S. Gov't