James Edward Morrow

US Patent:

40706710, Jan 24, 1978

Filed:

Sep 18, 1975

Appl. No.:

5/614456

Inventors:

James A. Morrow - Huntington Beach CA

Assignee:

Rockwell International Corporation - El Segundo CA

International Classification:

G01S 956

US Classification:

343 65LC

Abstract:

A set of three or more acoustic transponders positioned below the surface of the ocean is provided with logic circuitry that enables location of transponder positions merely by listening to transponder signals and also enables location of an unknown receiving station merely by listening to transponder signals. The transponders are self-synchronizing to eliminate the need for precision timing over long periods. In a first mode, each transponder transmits a signal to the surface and retransmits upon receipt of its echo to thereby provide depth data. In a second mode the transponders transmit to each other and retransmit an acknowledge signal upon receipt of a reply from one of the other transponders. This provides data to enable a remote station to calculate distances between the respective transponders. In a third mode, geographic location of the transponders is determined and the transponders continue to transmit, each resetting itself upon each transmission, and each transmitting in a master or slave relation with respect to the others thereby to enable a receiving station to determine its position with respect of the transponders by conventional methods of hyperbolic navigation.