SONAR SYSTEM USING ADAPTIVE BEAM FORMER

摘要

PURPOSE:To prevent degrading of characteristic and generation of noises by forming two beams close to a target direction estimated value to eliminate the discontinuity in the calculation of adaptive coefficient due to changeover in the direction of beam main axis due to time change in the target direction. CONSTITUTION:First and second estimated direction discrete value converters 70 and 71 and a multiplexer 80 are added to a sonar comprising an adaptive beam former (ABF), nonadptive waiting beam former (waiting CBF) and the like. The second converter 71 selects and outputs the direction alpham from two values - the discrete value alphal the closet to the target direction estimated value alpha which is outputted from the first converter 70 and the target direction estimated value alpha which is outputted from a target direction tracker 30. With such an arrangement, the calculation of coefficients of a variable filter for both directions alphal and alpham with a coefficient counter 43 can be done continuously regardless of switching in the direction of main axis of beam. This eliminates errors in the calculation to prevent the degrading of the ABF characteristic while removing noises from the beam output.