A METHOD MINIMIZING THE CORRELATION-PROPERTIES OF A NOISE FIELD AND IMPROVING DETECTION OF SIGNALS EMBEDDED IN ANISOTROPIC NOISE

This paper deals with the development of a processing technique that i mproves the signal-to-noise ratio (SNR) at the single sensor for a rec eived signal that is embedded in a partially correlated noise field. T he approach of this study is unique in that the noise is treated as be ing non-white and partially correlated. The concept of the proposed de velopment is based on the time interval over which the temporal cohere nce or correlation properties of a noise field are defined. For narrow band signals, the associated temporal coherence period is much longer than the correlation time interval of the anisotropic noise held, Thus , a coherent integration of discontinuous segments of received signals will enhance the SNR at the single sensor by lowering the correlation properties of the associated non-white noise. Reconstruction of the n arrow-band signal time series with improved SNR at the sensor will all ow the use of the existing high-resolution techniques to be utilized m ore effectively by lowering their threshold values in order to detect very weak signals. The intention here is to integrate the characterist ics of the real anisotropic noise field during the preliminary process ing stages of the received signals by an array of sensors. Simulations show that the proposed method can be integrated in the signal process ing functionality of sonar and radar systems.