GPS for navigation

[Forest]

has any one tried using a GPS or a GPS locater to navigate there ROV? :

[ROV-Control]

GPS underwater? Not really! There is no chance to get the satellite information underwater.

[Forest]

good point you would never get satellite under water

[SoakedinVancouver]

But you could get fancy and release the GPS module and its antenna to the surface, get a set of coordinate in, and reel the kit back down to the ROV. I am only half joking. Couple that with underwater dead reckoning and you might have some fairly precise navigation?

Stephen Young

[Danny]

it is pretty advanced but you could put a sonar emitter under the boat, and a receptor on the ROV, hook that into your display to show the distance from source and direction, and you can determine where the sub is in relation to the boat where the control is. It would probably need to be a larger ROV and not sure how you could make it work, but I heard of someone who used a similar method to locate non mobile camera placements on reefs and similar devices that his lab placed to film certain locations. Not sure how exactly it could be made to work, but that is one idea.

[weine]

it is pretty advanced but you could put a sonar emitter under the boat, and a receptor on the ROV, hook that into your display to show the distance from source and direction, and you can determine where the sub is in relation to the boat where the control is. It would probably need to be a larger ROV and not sure how you could make it work, but I heard of someone who used a similar method to locate non mobile camera placements on reefs and similar devices that his lab placed to film certain locations. Not sure how exactly it could be made to work, but that is one idea.

Yes, its advanced:)
Check this out, but I guess its not so cheap.... But anyway we can get ideas from this staff to make it in our garage:)
http://www.underwater-gps.com/images/dy ... s/g418.pdf

And this: http://www.youtube.com/watch?v=sN9EfsHqa04

[rovdude]

I might be crazy, but I am TRYING GPS. It will be floating on the top of the water with a pressure sensor so it can make sure it stays on the surface. It will basically be tethered to my ROV, with a reel on the ROV controlling how much tether is in the water, to make sure it is not too much - giving me inaccurate readings, or stuck under water without a signal

[rossrov]

Sounds like good fun stuff. What are you thinking of doing regarding the control and data/video? Wireless to/from the float? If so, I'd suggest starting with the GPS and the other antenna on opposite ends of the float to avoid any possibly of interference getting into the GPS receiver. Wi-Fi with a moderately directional antenna at the control station could be worth looking at, or, FPV and conventional RC gear. A failsafe so the ROV surfaces and maybe tether spools out if no data received from above after a given time. Simple pinger on the ROV in case something goes really wrong.