A Model for Target Ranging in Shallow Water and Short Ranges

Measuring the target range (ranging) in shallow water and at short distance is always affected by two factors namely reflection and refraction at the surface and bottom. Also since the maximum range is low, the loss is not significant. Therefore, received amplitude of multipath is high and comparable to the received wave in the direct way. Moreover, due to low bit angle of the surface and bottom reflection, the reflection coefficient is approximately equal to one resulting in low loss. In this paper, one effective and simple model is presented, for range measuring at shallow sound channels taking into consideration the environment parameters and computer simulation. This model, which is developed as part of the studies necessary for construction of practical prototype, covers on way loss, directivity of transducer and frequency response in the channel. Results suggest that in a channel with depth of 20 meter ranging for low ranges (600 meter) is possible with 2%