Bistatic sonar

Most sonar systems are monostatic, in that the transmitter and receiver are in the same place. Bistatic sonar describes when the transmitter and receiver(s) are separated by a distance large enough to be comparable to the distance to the target. Most sonar systems are monostatic, in that the transmitter and receiver are in the same place. Bistatic sonar describes when the transmitter and receiver(s) are separated by a distance large enough to be comparable to the distance to the target. This is a loss in sound level which happens while the sound pulse travels from projector to target and from target to receiver. There are 3 different mechanisms causing transmission Loss: spherical (or cylindrical in shallow water) spreading, absorbing and scattering by ocean media inhomogeneities. Transmission loss (TL) is proportional to range, (the longer the sound travels the more the loss), and to sound frequency. In monostatic sonar the sound first travels from projector to target, then the same way back from target to receiver, so two-way loss is just 2TL, where TL is one-way loss.In bistatic sonar the total loss (in decibels) is a sum of TLpt (from projector to target) and TLtr (from target to receiver).