Discrimination of underwater materials located on a declined seabed

A circular six-receiver array centered around the transmitter and a compens ation method are proposed in order to improve the discrimination ratio of u nderwater materials located on a declined seabed. The signal intensity refl ected from the seabed is employed as data for neural network processing. Co mpared to the distribution of the intensities of the original data acquired from the declined seabed, the compensated values approach those acquired f rom a planar seabed, which are employed as the standard learning data for n eural network discrimination. A comparison of the results of discrimination of the underwater materials with and without compensation verifies the eff iciency of the method. However, the intensity of the echo signal decreases with increasing angle of decline, and the discrimination ratio is reduced a ccordingly. The valid limitation of the angle of decline for the compensati on method is about 9 degrees, according to the discrimination results obtai ned under the conditions of different angles of decline.