Abstract:
A torpedo relative position measuring system, including an active sonar system and a passive magnetic system, is coupled to computing apparatus which operates in response to a set of stored computer programs, all located in the torpedo for homing in on a ferrous target. At long ranges and mid ranges, the torpedo is directed to the target by the sonar system, while at near ranges the magnetic system determines the x, y, z, relative position coordinates between the target and the torpedo in accordance with a calibrated stored magnetic model of the target and numerical solution of the non-linear equations linking the target's magnetic field, as measured at the torpedo, with the target's relative position. Guidance information derived therefrom is then fed to the torpedo's guidance system. With the magnetic system providing the relative position of the target at close range, the torpedo's normal guidance system can readily steer the torpedo to a desired hit point on the target.