Responses of a Transponder and Positioning of a Deep-tow System

Abstract

An acoustic transponder navigation system is used for positioning of a deep-tow system. The navigation system utilizes travel-time of acoustic pulse through the direct path to know a distance, because the direct wave does not decay a lot and is observed as the first arrival. A wave pulse propagating another path is, however, detected at the surface. The experiment carried out during the test operation of a deep-tow system shows the following results: (1) a relay transponder responds to interrogation pulses propagating through a direct path and another path, (2) response pulses propagating through a dirct path are observed at the surface, and (3) a reflected pulse of the response at the surface is detected at the deep-tow system. This evidence tells us that exhaustion of a battery of a transponder must be estimated based on multi-response to an interrogation, and the following possible use: (1) as an inverted echo sounder, and (2) positioning of a deep-tow system using multiresponse.