<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:10pt"><div><span>Hi Nathan,</span></div><div style="color: rgb(0, 0, 0); font-size: 13.333333969116211px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>when they thought they had pin pointed where MH370's emergency beacon was</span></div><div style="color: rgb(0, 0, 0); font-size: 13.333333969116211px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>transmitting from, they sent down an AUV to do a grid search. It was coming up</span></div><div style="color: rgb(0, 0, 0); font-size: 13.333333969116211px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif;
font-style: normal; background-color: transparent;"><span>periodically & transmitting data. All it's scanning images were then looked at.</span></div><div style="color: rgb(0, 0, 0); font-size: 13.333333969116211px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>If it had found anything of interest, there would have been coordinates with the </span></div><div style="color: rgb(0, 0, 0); font-size: 13.333333969116211px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>image so they could then send a rov down to that point.</span></div><div style="color: rgb(0, 0, 0); font-size: 13.333333969116211px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color:
transparent;"><span>They have spent billions of dollars trying to find that plane.</span></div><div style="color: rgb(0, 0, 0); font-size: 13.333333969116211px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>Depending on the depth you are looking at, there are units that are towed behind boats</span></div><div style="color: rgb(0, 0, 0); font-size: 13.333333969116211px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>at a depth & scan the sea floor.</span></div><div style="color: rgb(0, 0, 0); font-size: 13.333333969116211px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>Regards Alan</span></div><div><br></div> <div style="font-family:
HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 10pt;"> <div style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 12pt;"> <div dir="ltr"> <hr size="1"> <font size="2" face="Arial"> <b><span style="font-weight:bold;">From:</span></b> Marc de Piolenc via Personal_Submersibles <personal_submersibles@psubs.org><br> <b><span style="font-weight: bold;">To:</span></b> personal_submersibles@psubs.org <br> <b><span style="font-weight: bold;">Sent:</span></b> Tuesday, June 3, 2014 4:50 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [PSUBS-MAILIST] Surface controlled drones<br> </font> </div> <div class="y_msg_container"><br>Microwaves will definitely not allow you to communicate with a deeply <br>submerged drone. There is a narrow range of frequencies at the lower end <br>of the EM range which can penetrate a few feet into water with
<br>acceptable attenuation, but that won't help you at great depth. The data <br>link problem is the biggest one for ROVs, and accounts for the fact that <br>they are mostly tethered, with rare exceptions designed for limited <br>autonomous navigation and data gathering (and those can't send data to <br>the surface in real time).<br><br>For exactly the same reason, underwater navigation is also a problem.<br><br>Marc de Piolenc<br><br>On 6/3/2014 5:27 AM, Nathan.tuttle via Personal_Submersibles wrote:<br>> Hey I am a submersible enthusiast and an expert engineer.<br>><br>> One thing that is bugging me is why communication with devices at great depths (the very bottom of the ocean) seems to be so hard.<br>><br>> The thing I am working on is miniature drones fully equipped and deployed en masse to scan and collect data from the bottom of the ocean.<br>><br>> Primarily, I want to find Amelia Earharts wreckage ;)<br>><br>> My
question is, would it be difficult to create an underwater device that can communicate via microwave to surface?<br>><br>> Microwaves on the electromagnetic spectrum can pass through things in a line of sight manner if there is nothing obstructing them.<br>><br>> But I am weak on my physics and maybe the several billion tons of water that it has to pass through would squelch the signal.<br>><br>> Is there a means of telecommunication with high enough bandwidth to transfer signals from that distance and that depth?<br>><br>> Although our earth is covered 70% of water. I think we have seen technology come to the point where a mass deployment of small controllable drones equipped with detection devices could search the sea floor.<br>><br>> I would great appreciate your input.<br>><br>> Sent from my iPad<br>> _______________________________________________<br>> Personal_Submersibles mailing list<br>> <a
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