NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Navigate using seafloor data
From: Lu Abel
Date: 2017 Sep 15, 16:19 +0000
From: John D. Howard <NoReply_Howard@fer3.com>
To: luabel@ymail.com
Sent: Friday, September 15, 2017 9:05 AM
Subject: [NavList] Navigate using seafloor data
From: Lu Abel
Date: 2017 Sep 15, 16:19 +0000
That might work for coastal navigation when you are "on soundings" but I think taking soundings (even if by modern means such as sonar) when the ocean is three miles deep would be somewhere between extremely difficult and impossible.
I do remember taking a coastal navigation course pre-GPS where we did do one exercise of taking a hypothetical run of soundings over a period of time, plotting them spaced by distance run between soundings on a sheet of transparent paper, and then overlaying it on a chart and trying to estimate our position. Pretty low on the accuracy scale, but if nothing else is available, it's better than nothing.
From: John D. Howard <NoReply_Howard@fer3.com>
To: luabel@ymail.com
Sent: Friday, September 15, 2017 9:05 AM
Subject: [NavList] Navigate using seafloor data
Hello,
With all the talk of Cel-Nav as a backup to GPS for Navy ships is there is a different way that would be secure?
Cruise missles can find their target by following a very detailed profile of the ground. Could a data base be made of the sea floor that would tell a ship where it is? The old pilot books would make refrence to depth, type of seabed material, and the like - throw a lead over and see. It seems to me that a detailed profile map of the seafloor could be made as an aid to navigation.
There are already very good INS systems but they need to be updated from time to time because of progression. I think a seabed scan compared to a profile could be used.
Any thoughts?
John H.