US 4,229,809 AGranted

Acoustic under sea position measurement system

AssigneeSperry Corporation

InventorJulian H. Schwalbe

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Abstract

The invention concerns acoustic under-water measurement apparatus for determining the location with respect to a surface vessel of objects such as submersible vessels, pipe-riders, mining apparatus, or the like, including tethered submersible vessels. A receiver hydrophone set located on the tethered vehicle receives acoustic reply pulses from sea bottom transponders, telemetering the times of reception to a surface support ship via conductors in the tether cable. Signals obtained at the surface ship directly from the transponders and indirectly via the tether cable conductors are combined aboard the surface ship for computing the positions of both vessels with respect to a base line established by the sea bottom transponders. The system is self-calibrating, so that an expensive survey to determine the actual locations of the bottom transponders is no longer required.

Claims38

Dependent claims

In a machine method of establishing positional data with respect to a base line disposed at a marine bottom, the steps of:

providing first and second acoustic pulse transponder means one each at the respective ends of said base line,
providing third acoustic pulse transponder means at support means disposed intermediate said marine bottom and a location at the associated marine surface,
providing pulse interrogator-receiver means at said location for cooperative communication with said first, second, and third acoustic pulse transponder means by providing respective first, second and third pulse responses thereto at said interrogator-receiver means,
providing hydrophone means at said support means responsive to said first and second acoustic pulse transponder means for providing respective fourth and fifth pulse responses at said interrogator-receiver means,
utilizing said first, second, and third pulse responses at said location for computing the respective magnitudes of the distance vector R.sub.SA from said location to said first acoustic pulse transponder means, of the distance vector R.sub.SB from said location to said second acoustic pulse transponder means, and of the distance vector R.sub.SC from said location to said third acoustic pulse transponder means,
utilizing said first and fourth pulse responses at said location for computing the magnitude of the distance vector R.sub.AC between said first and third acoustic pulse transponder means, and
utilizing said second and fifth pulse responses at said location for computing the magnitude of the distance vector R.sub.BC between said second and third pulse transponder means.

4 more elements

Apparatus for establishing positional data with respect to a base line disposed at a marine bottom, said apparatus comprising:

first and second acoustic pulse transponder means one each at the respective ends of said base line,
third acoustic pulse transponder means at support means disposed intermediate said marine bottom and a location at the associated marine surface,
pulse interrogator-receiver means at said location for cooperative communication with said first, second, and third acoustic pulse transponder means for providing respective first, second, and third pulse responses at said interrogator-receiver means,
hydrophone means at said support means responsive to said first and second acoustic pulse transponder means for providing respective fourth and fifth pulse responses at said interrogator-receiver means,
first slant range computing means utilizing said first, second, and third pulse responses at said location for computing the respective magnitudes of the distance vector R.sub.SA from said location to said first acoustic transponder means, of the distance vector R.sub.SB from said location to said second acoustic pulse transponder means, and of the distance vector R.sub.SC from said location to said third acoustic pulse transponder means,
second slant range computing means utilizing said first and fourth pulse responses at said location for computing the magnitude of the distance vector R.sub.AC between said first and third acoustic pulse transponder means, and
third slant range computing means utilizing said second and fifth pulse responses at said location for computing the magnitude of the distance vector R.sub.BC between said second and third pulse transponder means.

4 more elements

Dependencies are inferred from the claim text.