Measurement and Extraction of Micro-Doppler Feature of Underwater Rotating Target Echo

Underwater vehicles detection and identification is an important part of maritime security surveillance. In the sonar community, there are few studies using micro-Doppler features to detect and classify various motions of underwater targets. Regrettably, the theoretical derivation and simulating analysis could only be given to verify that the micro-Doppler characteristic signal could be existed. In this paper, the micro-Doppler feature induced by a rotating sphere would be measured in a practical sonar system. Based on model of the underwater rotating subject, due consideration about the measurement sonar system would be described in detail. And after the measurement of reflection echoes was finished, the adequate analysis about reflection echoes in time and micro-Doppler in frequency domain was given.

I. Introduction

The use of Autonomous Underwater Vehicles (AUVs) in maritime operations has increased significantly over the past decade. Many research about the detection and recognition of AUV have been paid more and more attention. One of the challenges to distinguish these underwater targets is its small size and weak reflected strength, especially since AUV could have flexible motion capability. Thus, in active echo mode, it is difficult to recognize these targets with the help of the structure of highlight echoes in the past.