Research On Frequency-Alterable Underwater Cooperate Target Localization

As a mature, simple and effective system, Underwater Cooperate Target Localization (UCTL) system is widely used. With the Unmanned Undersea Vehicle getting more intelligent and frequency band using more extensive, the frequency of cooperative sound source should be changed. At the same time, in order to get better positioning effect, the signal type will be various. The main purpose of the Frequency-Alterable UCTL system is the ability to receive and process diverse signal form and frequency, and ultimately realize general-utility of equipment.It is one of the basic tasks in the UCTL that detection and time delay estimation of CW signal with known center frequency. On this basis, the method that the center frequency can be freely set is proposed to improve the performance of the receiver. For CW signal with unknown center frequency, adaptive frequency measure and two-stage filter is proposed and simulated.Linear Frequency Modulated (LFM) signal has high time-frequency resolution with adjusting time-bandwidth product. LFM signal is applied to UCTL system in this paper. It is processed with different kinds of time-frequency analysis method, and simulated in different background of underwater acoustic channels. A series of signal process method such as replica correlation, WVD and FRFT are applied for LFM signal process. At last, the detection and parameter estimation results are given.