[PSUBS-MAILIST] Ping 360 Scanning Sonar

Fri Sep 27 03:19:35 EDT 2019

Hi Alan,

you're right, it's probably a lot of work to get to that stage.  Also a
lot of components and complexity to keep dry and reliable, I feel that
that might be half (or more) of the challenge.

I would start with a smaller part first, like a compass using a fiber optic
gyro and a 3D flux gate compass.  Then get some experience dealing with the
issues of reliability of more complex/sensitive electronics in a sub-interior
environment. Once I think I've got some electronic-environmental solutions,
I'll look at getting a simple sonar setup. And just keep building from there.

For your powered buoy, will it be able to relay position data back to the sub?

I had an idea for using a tethered buoy to do positioning.  The buoy would be
tethered with an ROV cable which was strong enough to be the sole tether and
could do (relative) high speed digital comms between sub and buoy.  The buoy
would have a GPS receiver and an acoustic pinger on board.  On board the sub,
a direction finding passive sonar (3 or more transducers) and a digital depth
gauge.

To get the sub's position, send a command to the buoy to return a GPS reading
and send a ping at the same time, simultaneously take the sub's depth reading.
Once you have the depth of the sub (digital depth gauge), the direction
of the buoy (direction finding sonar), and the distance from the sub to the buoy
(time from the ping sent to ping received), it's a bit of trigonometry but you
can determine the position of the sub relative to the buoy. This sub-buoy position
delta would be used as an offset to the returned GPS coordinates, giving the
actual position of the sub.

Cheers,
  Ian.

-----Original Message-----
>From: Alan via Personal_Submersibles <personal_submersibles at psubs.org>
>Sent: Sep 26, 2019 10:50 PM
>To: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
>Subject: Re: [PSUBS-MAILIST] Ping 360 Scanning Sonar
>
>Hi Ian,
>that sounds like a lot of work. Good project though.
>I am still looking at options for getting a GPS signal in to a standard chart
>plotter. Best prospect so far is a motorised buoy with GPS & sonar array
>to track & follow the sub. I may be tempted to pursue it as I have access
>to a sonar expert.
>Cheers Alan
>
>> On 27/09/2019, at 4:16 PM, irox via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>> 
>> 
>> Hi Alan,
>> 
>> one of your fwd's from Blue Robotics had links to it, it looks really neat.
>> Probably the most exciting part is the open source aspect, since we can
>> potentially customize the software to our needs.
>> 
>> One project I'm interested in advancing is combining FiberOptic Gyros, Mems
>> accelerometers, 3D flux gate compass, and sonar, as part of a underwater
>> navigation, mapping and positioning system.
>> 
>> Essentially, the IMS sensors are used to understand short term movements of
>> the sub (drift won't be a worry short term), which helps with accurately
>> determining the positioning of the sub relative to the sonar targets.
>> Then do characterization analysis on the sonar data to determine which
>> objects are static (not moving) and objects not persistent (moving or unreliable
>> to image with sonar).  This allows us to generate a persistent sonar
>> image/map (remembering all the things that were observed previously), and use
>> the previously identified static objects/characteristics to accurately determine the
>> sub's current position/location via sonar and IMS data.
>> 
>> I did build part of a proto-type for this a few years ago, but other things
>> came up.  I think this would be great thing to add to Gamma. :)
>> 
>> Cheers,
>>  Ian.
>> 
>> 
>> -----Original Message-----
>>> From: Alan via Personal_Submersibles <personal_submersibles at psubs.org>
>>> Sent: Sep 24, 2019 12:42 AM
>>> To: personal_submersibles at psubs.org
>>> Subject: [PSUBS-MAILIST] Ping 360 Scanning Sonar
>>> 
>>> Hi all,
>>> thought this video on the Blue Robotics "Ping 360" scanning sonar was good,
>>> https://m.youtube.com/watch?v=yXYo2c0TSJY
>>> I am not sure whether it was on their site last time we discussed it.
>>> It is rated to 300 meters.
>>> Alan
>>> _______________________________________________
>>> Personal_Submersibles mailing list
>>> Personal_Submersibles at psubs.org
>>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
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>
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