<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content="text/html; charset=US-ASCII" http-equiv=Content-Type>
<META name=GENERATOR content="MSHTML 11.00.10570.1001"></HEAD>
<BODY id=role_body style="FONT-SIZE: 10pt; FONT-FAMILY: Arial; COLOR: #000000"
bottomMargin=7 leftMargin=7 topMargin=7 rightMargin=7><FONT id=role_document
color=#000000 size=2 face=Arial>
<DIV>Alan,</DIV>
<DIV> </DIV>
<DIV>That's quite interesting. I haven't been familiar with acoustic
modems. In addition to positioning, I can appreciate that they would have
greater range capabilities for communication than the other (but much cheaper)
technology that we have accessible as amateurs</DIV>
<DIV> </DIV>
<DIV>I've had to pull way back from my focus on sub design and technology for a
good while. By the time I return I'm hoping you guys will be field testing
Inertial Navigation Systems and have a couple of
different configurations to share info on.</DIV>
<DIV> </DIV>
<DIV>Cheers,</DIV>
<DIV>Jim </DIV>
<DIV> </DIV>
<DIV>
<DIV>In a message dated 3/24/2017 3:48:40 P.M. Central Daylight Time,
personal_submersibles@psubs.org writes:</DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" color=#000000 size=2 face=Arial>
<DIV>Jim,</DIV>
<DIV id=AppleMailSignature>just had a look in Sea Technology magazine March
edition, ( free online magazine)</DIV>
<DIV id=AppleMailSignature>& saw this...</DIV>
<DIV id=AppleMailSignature><A title=http://www.link-quest.com/html/intro2.htm
href="http://www.link-quest.com/html/intro2.htm">http://www.link-quest.com/html/intro2.htm</A></DIV>
<DIV id=AppleMailSignature>It is a small module that tracks an underwater
vehicle, has GPS & communicates</DIV>
<DIV id=AppleMailSignature>to the vehicle via an onboard PC or whatever.
Haven't studied it, but I am sure</DIV>
<DIV id=AppleMailSignature>it could translate the underwater vehicles position
to maps on the vehicles PC.</DIV>
<DIV id=AppleMailSignature>These days you have GPS mapping apps on your cel
phone, so it wouldn't be too</DIV>
<DIV id=AppleMailSignature>hard. The next stage would be using the position
signal from the submarine to</DIV>
<DIV id=AppleMailSignature>control motors on the buoy to follow it. On quad
copters they have GPS & return</DIV>
<DIV id=AppleMailSignature>to start functions that return the quad copter to
it's launch position should it's</DIV>
<DIV id=AppleMailSignature>transmitter lose contact. So the sought of
technology to control the buoy thrusters</DIV>
<DIV id=AppleMailSignature>through position signals is alive & well &
cheap.</DIV>
<DIV id=AppleMailSignature> I won't be pursuing it, as I need to
make my sub first :)</DIV>
<DIV id=AppleMailSignature>Alan</DIV>
<DIV id=AppleMailSignature><BR><BR>Sent from my iPad</DIV>
<DIV><BR>On 25/03/2017, at 6:53 AM, Alan via Personal_Submersibles <<A
title=mailto:personal_submersibles@psubs.org>personal_submersibles@psubs.org</A>>
wrote:<BR><BR></DIV>
<BLOCKQUOTE type="cite">
<DIV>
<DIV>Jim,</DIV>
<DIV>yes. Just an intermittent signal every 10 seconds or so. I have</DIV>
<DIV>read about text type communication systems.</DIV>
<DIV>Here is a passage from a paper that talks about a buoy device.</DIV>
<DIV><BR>
<DIV title="Page 2" class=page>
<DIV class=layoutArea>
<DIV class=column>
<P><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: 'Times New Roman'">An
underwater GPS is primarily a combination of a GPS and an acoustic
positioning system and consists of two types [12-19]: a sea surface buoy
system using a long baseline and carrying a GPS receiver, which can track,
monitor, and dynamically position underwater targets from a sea surface,
coastal land, and a plane and has a large operating range but can only
position underwater targets that carry acoustic transponders in certain
waters; and a system which uses a mother ship equipped with a short baseline
or ultra short baseline transceiver and a GPS receiver, which is mobile and
flexible but also can only position targets equipped with acoustic
transponders. Therefore, this paper proposes a way of positioning combining
an ultra short baseline, a forward-looking sonar and a GPS receiver,
overcoming the limitation of the existing underwater GPS positioning
technology that it can only position targets equipped with acoustic
transponders and realizing the real-time positioning of the longitude and
latitude coordinates of any unknown targets in any waters in the WGS84
ellipsoidal coordinate system, and it is also highly mobile.</SPAN></P>
<P><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Times New Roman'">Alan </SPAN></P></DIV></DIV></DIV>
<DIV>Sent from my iPad</DIV></DIV>
<DIV><BR>On 25/03/2017, at 6:06 AM, via Personal_Submersibles <<A
title=mailto:personal_submersibles@psubs.org>personal_submersibles@psubs.org</A>>
wrote:<BR><BR></DIV>
<BLOCKQUOTE type="cite">
<DIV>
<META name=GENERATOR content="MSHTML 11.00.10570.1001"><FONT color=#000000
size=2 face=Arial>
<DIV><FONT size=3>Alan,</FONT></DIV>
<DIV><FONT size=3>Transmit GPS positions wirelessly where? You
didn't mean down to the sub, did you?</FONT></DIV>
<DIV><FONT size=3>Jim</FONT></DIV>
<DIV> </DIV>
<DIV>
<DIV>In a message dated 3/23/2017 10:07:37 P.M. Central Daylight Time, <A
title=mailto:personal_submersibles@psubs.org>personal_submersibles@psubs.org</A>
writes:</DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" color=#000000 size=2 face=Arial>
<DIV>Jim,</DIV>
<DIV id=AppleMailSignature>re the tow behind buoy (pronounced boy); it
would be possible to make a </DIV>
<DIV id=AppleMailSignature>buoy with motors on it that tracked your sub
& transmitted GPS positions</DIV>
<DIV id=AppleMailSignature>wirelessly. Minn kota have a system that
controls their thruster to keep</DIV>
<DIV id=AppleMailSignature>a boat steady on a certain
coordinate. </DIV>
<DIV id=AppleMailSignature>Alan</DIV>
<DIV id=AppleMailSignature><BR>Sent from my iPad</DIV>
<DIV><BR>On 24/03/2017, at 3:43 PM, via Personal_Submersibles <<A
title=mailto:personal_submersibles@psubs.org>personal_submersibles@psubs.org</A>>
wrote:<BR><BR></DIV>
<BLOCKQUOTE type="cite">
<DIV>
<META name=GENERATOR content="MSHTML 11.00.10570.1001"><FONT
color=#000000 size=2 face=Arial>
<DIV><FONT size=3>Here's a link that gives quite a bit of information
including a reference to their Windows-based software. Once you
open the link, the more you scroll down the more you will see; it goes
a long way! <A
title=http://www.seismic.com.au/assets/pdf/SBG_Systems-Ellipse_Series_Brochure.pdf
href="http://www.seismic.com.au/assets/pdf/SBG_Systems-Ellipse_Series_Brochure.pdf">http://www.seismic.com.au/assets/pdf/SBG_Systems-Ellipse_Series_Brochure.pdf</A></FONT></DIV>
<DIV><FONT size=3></FONT> </DIV>
<DIV><FONT size=3>GPS is great as a starting point before you submerge
and for telling you where you are once you surface. Too bad
radio signals don't propagate so well under water. In the
past we've discussed mounting a GPS antenna on a Diver Below buoy with
a cable running to the sub. I don't recall what was said
regarding theoretical depth limitations for such a setup as well as
the hydrodynamics of towing it.</FONT></DIV>
<DIV><FONT size=3></FONT> </DIV>
<DIV><FONT size=3>It would be really interesting to see how well your
INS position matches up with your GPS when you resurface. I like
the idea of knowing just where you are with reasonable precision when
submerged, being able to return to a precise location on another day,
being able to search or survey methodically, navigating from A to B to
C, etc.</FONT></DIV>
<DIV><FONT size=3></FONT> </DIV>
<DIV><FONT size=3>Jim T.</FONT></DIV>
<DIV> </DIV>
<DIV>
<DIV>In a message dated 3/23/2017 7:55:50 P.M. Central Daylight Time,
<A
title=mailto:personal_submersibles@psubs.org>personal_submersibles@psubs.org</A>
writes:</DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" color=#000000 size=2
face=Arial>
<DIV class=moz-cite-prefix>On 3/23/2017 6:40 PM, Brian Cox via
Personal_Submersibles wrote:<BR></DIV>
<BLOCKQUOTE cite=mid:20170323154013.EA88CFB6@m0087798.ppops.net
type="cite">
<DIV style="FONT-SIZE: 10pt; FONT-FAMILY: Arial, sans-serif">
<DIV>There needs to be an underwater GPS
!!</DIV></DIV></BLOCKQUOTE><BR>I remember a discussion, long ago,
about a GPS antenna on a mast. I don't recall any
resolution.<BR><BR><BR>Mike<BR><BR>
<TABLE style="BORDER-TOP: #d3d4de 1px solid">
<TBODY>
<TR>
<TD style="WIDTH: 55px; PADDING-TOP: 13px"><A
title=https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=icon
href="https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=icon"
target=_blank><IMG
title=https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=icon
style="HEIGHT: 29px; WIDTH: 46px"
alt=https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=icon
src="https://ipmcdn.avast.com/images/icons/icon-envelope-tick-round-orange-animated-no-repeat-v1.gif"
width=46 height=29></A></TD>
<TD
style="FONT-SIZE: 13px; FONT-FAMILY: Arial, Helvetica, sans-serif; WIDTH: 470px; COLOR: #41424e; PADDING-TOP: 12px; LINE-HEIGHT: 18px">Virus-free.
<A
title=https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=link
style="COLOR: #4453ea"
href="https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=link"
target=_blank>www.avast.com</A>
</TD></TR></TBODY></TABLE><BR><BR>_______________________________________________<BR>Personal_Submersibles
mailing list<BR><A
title=mailto:Personal_Submersibles@psubs.org>Personal_Submersibles@psubs.org</A><BR><A
title=http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</A><BR></FONT></BLOCKQUOTE></DIV></FONT></DIV></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<DIV><SPAN>_______________________________________________</SPAN><BR><SPAN>Personal_Submersibles
mailing list</SPAN><BR><SPAN><A
title=mailto:Personal_Submersibles@psubs.org>Personal_Submersibles@psubs.org</A></SPAN><BR><SPAN><A
title=http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</A></SPAN><BR></DIV></BLOCKQUOTE><BR><BR>_______________________________________________<BR>Personal_Submersibles
mailing list<BR><A
title=mailto:Personal_Submersibles@psubs.org>Personal_Submersibles@psubs.org</A><BR><A
title=http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</A><BR></FONT></BLOCKQUOTE></DIV></FONT></DIV></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<DIV><SPAN>_______________________________________________</SPAN><BR><SPAN>Personal_Submersibles
mailing list</SPAN><BR><SPAN><A
title=mailto:Personal_Submersibles@psubs.org>Personal_Submersibles@psubs.org</A></SPAN><BR><SPAN><A
title=http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</A></SPAN><BR></DIV></BLOCKQUOTE></DIV></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<DIV><SPAN>_______________________________________________</SPAN><BR><SPAN>Personal_Submersibles
mailing list</SPAN><BR><SPAN><A
title=mailto:Personal_Submersibles@psubs.org>Personal_Submersibles@psubs.org</A></SPAN><BR><SPAN><A
title=http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</A></SPAN><BR></DIV></BLOCKQUOTE>=<BR><BR>_______________________________________________<BR>Personal_Submersibles
mailing
list<BR>Personal_Submersibles@psubs.org<BR>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles<BR></FONT></BLOCKQUOTE></DIV></FONT></BODY></HTML>