[PSUBS-MAILIST] RE: Underwater Navigation

[Brent Hartwig <brenthartwig@hotmail.com>]

I remembered seeing the below data from the people that now operate the S103 Lula. Here is the link.

http://www.rebikoff.org/html/uw_navigation.html


Navigation/GIS

	"Submarine LULA is operated in conjunction with a precise underwater navigation system. This is particularly important when doing archaeological work, so as to be able to define the exact geographical position of a wreck or archaeological site and to refind the location in follow-up dives.

	The system used is a “long baseline system” (LBL). The system functions with several transmitters/receivers which communicate via high frequency acoustic signals and calculate the submarine´s position underwater.

		The transmitter/receiver mounted on the submarine is connected to a notebook computer in the interior of the cabin and shows the submersible´s position and depth with a precision of 1 meter at all times.
	By importing a sea chart into the system, the submarine´s geographical position can be displayed on a sea chart.

	The distance sailed underwater is logged automatically. Later on, this data, can be superimposed on a sea chart to make the actual underwater route visible."

Regards,
Brent Hartwig

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Date: Tue, 15 Jan 2008 10:29:16 -0700
From: antoine.delafargue@gmail.com
To: personal_submersibles@psubs.org
Subject: Re: navigation was Re: [PSUBS-MAILIST] teathers

For navigation near the bottom, I think another (expensive) solution is a doppler sonar:

 

the change in the signal frequency after it bounces on the bottom is translated into a speed relative to it. 3 orthogonal beams give the full velocity vector.

 

I am not sure but I guess it is used by AUVs, ROVs, dynamically positioned boats, navy seals...

A mixed task of mapping and positioning can be done too (cf Bill Stone experiments in Florida and with the AUV depthX)

 

Antoine