REVERBERATION FILTER, ACTIVE SONAR DEVICE, REVERBERATION REMOVING METHOD, AND REVERBERATION REMOVING PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a reverberation filter and the like that can accurately remove reverberation from a reflection wave.SOLUTION: The reverberation filter 10 includes reflection wave detection means 101 for detecting whether a level L of the reflection wave exceeds a level threshold Lth; duration measurement means 102 for measuring a duration T in which the level L of the reflection wave continues to exceed the level threshold Lth when the reflection wave detection means 101 detects that the level L of the reflection wave exceeds the level threshold Lth; and target echo determining means 103 for detecting whether the duration T measured by the duration measurement means 102 exceeds a duration threshold Tth, determines that a reflection wave in which the duration T exceeds the duration threshold Tth is a reverberation, and determines that a reflection wave in which the duration T does not exceed the duration threshold Tth is a target echo.