Estimation of Distance to Noise Signal Source by Two-Frequency Method with the Use of Band-Pass Filters

Abstract

The two-channel system of noise signal reception with different frequency filters in each channel is considered. With the use of such two-channel system two methods of distance estimation can be realized. The first method of distance estimation can be executed when it is possible to tune parameters of filters of two channels on frequency scale, and hence on distance. The second method of distance estimation can be executed when parameters of filters of two channels are fixed. In the first case the distance to the source is determined at equality of output signal to noise ratios in two channels. In another case — by calculations according to the relationship of output signal to noise ratios. Analytical description of a two-frequency method of determination of distance to noise signal source is received in two variants: when using optimum filters and when using filters with limited frequency band. Calculations for quantitative comparison and estimation of applicability of band-pass filters are carried out. It is shown that twochannel system with band-pass filters has no output characteristics symmetrical with respect to the center of distances determined as average geometrical value of distances of two filters tuning. Efficiency of the method will be different for signal source located closer or further than the center of distances. It is shown that the distance determination method based on tuning filter parameters on frequency cannot be realized in considered two-channel system similarly to how it occurs at the use of optimum filters. Functional dependences received in the research provide possibility of the further development of the two-frequency method of determination of distance to noise signal source with the use of band-pass filters for conditions of real noise.