<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div></div><div>Thanks Ian,</div><div>there is this Blue Robotics Sonar imaging scanner that has open source software.</div><div><a href="https://bluerobotics.com/store/sensors-sonars-cameras/sonar/ping360-sonar-r1-rp/">https://bluerobotics.com/store/sensors-sonars-cameras/sonar/ping360-sonar-r1-rp/</a></div><div>Alan</div><div><br>On 9/11/2020, at 8:36 AM, irox via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br><br></div><blockquote type="cite"><div><div style=""><div style="color: rgb(0, 0, 0); font-family: arial, sans-serif; font-size: 13px;"><br></div><span style="font-size: 13px;">MIT has published a paper on underwater positioning using Underwater Backscatter Localization which</span><div><span style="font-size: 13px;">might be of interest to some folks on the list.</span></div><div><span style="font-size: 13px;"><br></span></div><div><span style="font-size: 13px;">Although it seems more focused on positioning of un-powered or under-powered objects (fish, drones, etc</span><div><div style="color: rgb(0, 0, 0); font-family: arial, sans-serif; font-size: 13px;">- surface vessel knowing the position of an underwater object), and it's only a proof-of-concept</div><div style="color: rgb(0, 0, 0); font-family: arial, sans-serif; font-size: 13px;"> (the paper on covers 1D positioning, we'd really need 3D), it does offer some hope for a relatively cheap</div><div style="color: rgb(0, 0, 0); font-family: arial, sans-serif; font-size: 13px;">underwater positioning system in the future.</div><div style="color: rgb(0, 0, 0); font-family: arial, sans-serif; font-size: 13px;"><br></div><div style="color: rgb(0, 0, 0); font-family: arial, sans-serif; font-size: 13px;">The paper can be found here:</div><div style="color: rgb(0, 0, 0); font-family: arial, sans-serif; font-size: 13px;"><a href="http://www.mit.edu/~fadel/papers/UBL-paper.pdf">http://www.mit.edu/~fadel/papers/UBL-paper.pdf</a></div><div style="color: rgb(0, 0, 0); font-family: arial, sans-serif; font-size: 13px;"><br></div><div style="color: rgb(0, 0, 0); font-family: arial, sans-serif; font-size: 13px;">There is a kind of layman's summary here:</div><div style=""><span style="font-size: 13px;"><a href="https://hackaday.com/2020/11/08/under-the-sea-gps-uses-sound/">https://hackaday.com/2020/11/08/under-the-sea-gps-uses-sound/</a></span></div></div></div><div style=""><span style="font-size: 13px;"><br></span></div><div style=""><span style="font-size: 13px;">Pity there isn't a a cheap sonar "hackers" kits (although some have do things with PC sound cards).</span></div><div style=""><span style="font-size: 13px;">On the radio side of things I can take a USB SDR (Software Defined Radio) and build a radio telescope</span></div><div style=""><span style="font-size: 13px;">for well under $100 (actually, I think it was under $50 in the end), would be great to be able to have</span></div><div style=""><span style="font-size: 13px;">that flexibility for playing with sonar.</span></div><div style=""><span style="font-size: 13px;"><br></span></div><div style=""><span style="font-size: 13px;">Cheers,</span></div><div style=""><span style="font-size: 13px;"> Ian.</span></div><div style=""><span style="font-size: 13px;"><br></span></div></div>
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