ZHU Daizhu1,2 WANG Zijuan3 CHEN Yang3

(1　　Shanghai Marine Electronic Equipment Research Institute Shanghai 201108)

(2　  School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiaotong University Shanghai 200240)

(3　  National Laboratory of Underwater Acoustic Technology,Harbin Engineering University Harbin 150001)

Received May 25, 2009

Revised Jul. 7, 2009

Abstract There are highly intensive and stable line-spectrums in the radiated noise of passive target, and different targets have line-spectrums with different frequencies. This paper puts forward Conventional BeamForming (CBF) variance-of-frequency detector, which weights bearing spectrum using the variance of frequency of line spectrum with maximum amplitude in each azimuth. It is able to suppress multi-target interferences effectively, and detect faint signal in the background of strong interferences. What's more, CBF variance-of-frequency detector needs only three-dimension display, while other line-spectrum detectors require for four-dimension display. The simulation and trial data analysis show that the CBF variance-of-frequency detector is able to detect faint line-spectrum target in the background of the continuous spectrum strong interferences.

PACS numbers:43.30,43.60