A new algorithm of background equalization in digtal sonar

摘要

Background equalization technique has been extensively studied in the field of fre quency spectrum analysis. It has been proved an effective method to improve line spectrum extraction. In a multi-beam digital sonar system, the time/bearing display is the most im portant interface between signal processing module and console module. It has been proved that the system gain is often lost in the illterface between these two modules. Background equalization technique can improv the overall performance of the time/bearing display win dow. The result of post processing of multi-beam data is filtered each time before displayed in screen. It is shown that the algorithm of median value filtering combined with OTA (Order Truncate Average) method is an efficient technique to equalize the non-uniform, non-stationary background data. A variable length of window is adopted to match the different width of main lobe of beam patterns. The results of system simulation show that the algorithm described in this paper is efficient in the case that the background of multi-beam data is not