Effective range indication for underwater practice mine - uses transmitter signals picked up by on board sonar to provide acoustic representation

摘要

The effective range indicator uses one or more transmitters with different frequencies associated with the marker (3) for the mine (2). The transmitted signals are received by a ship (1) within the vicinity of the mine (2) and used to provide an acoustic representation of the mine detonation and the working range, via an onboard loud-speaker. Pref. two transmitters are used, the reception of one signal indicating that the ship (1) is above the mine (1) within the destructive range (A), but without detonation of the mine (2) the reception of the other signal indicating that the mine (2) has been detonated, but that the ship (1)is out of range and the reception of both signals indicating that the mine has been detonated and that the ship (1) is in range. The indication is unaffected by currents and surface winds.