Underwater Camera - hmm

[robh2o]

I would like any help with finding a proper sub to explore my local lake. I know of tons of objects (cars, boats, planes, etc) that are waiting to be explored.

I am planning on building or modifying a platform. It needs to be able to carry a camera capable of clear underwater video. This would probably also mean a scuba diver style LED light. We would also like some sensors or even GPS if it even works underwater. Range is important as well.

Any help, links, comments are appreciated.

Thanks in advance!

Rob

[wayne frey]

Try www.supercircuits.com. They have several

Try www.supercircuits.com. They have several camreas for underwater use. Mount that on a platform like Tim Smalley's ROV, and you are in business.

[robh2o]

The camera looks great, now

The camera looks great, now what i need is info on this ROV. I cant wait to email you video!!!

[tmsmalley]

I have a few photos

I have a few photos of the ROV and more info about where to get plans etc. on my site. There are a number of homebrew ROV websites if you do a Google search for them. They will have info on how to build a camera housing using PVC material.

I have some 8 conductor 22 gauge wire (cheap!) - If you need it send me an email. I could be wrong but I do not believe that GPS will work underwater - it doesn't even penetrate a heavily leafed tree very well!

Some guys have mounted a small compass in the bottom portion of the camera's area of view so you can see which way you are pointed. Not super acurate but fine for the hobbyist.

Go to www.RC-submarines.com and click on "My Projects".
Woo Hoo! It's RC-Submarines.com





Edited By TMSmalley on 1078854388

[skuggan]

A GPS will reach down

A GPS will reach down about 1m under water.
But with the accuracy they give you as a none military, they only guarantee that its inside of 30 meters.
Tim how deep can you go with your camera without losing to much quality?
I was thinking about building the same kind of camera that Ramius II is doing, as he is helping me
Im currently checking around for transmitters since the lower freq you can get is the best when it comes to going thru the water I was thinking a 400 mhz from super circuits but they don't tell what power it has, and that is pretty important.

[germbrat]

for the cameras ability to

for the cameras ability to send a signal through water i have an idea that i would like your opinion on. What if you attached the reciever to a rc boat like one of the model warship boats. this way you could simply use a seperate controller and move the boat in the general area of your sub. You could then have the signal transmitted agiain from the boats deck(above water) to another reciever or just have a wire float behind your boat. On the bottom of the boat you could attach some sort os satellite dish reciever to pick up signals better. this way at most your signal travels maybe 8 feet to the reciever.

[interpol]

Actually, you would be better

Actually, you would be better off mounting an additional antenna underneath the waterline. The majority of radio signal loss in above water to under water transmissions is the refraction that occurs due to the change of medium.

[bob the builder]

Just remember... by adding a

Just remember... by adding a tether to your sub, your compounding the chances of it getting fouled by something not under your control.

I have a hard enough time keeping weeds, plastic bags, and the occasional blob of alge out of my prop without needing to worry about fouling it in my own antenna lead.

And that doesn't even take into consideration other boats or subs operating in your area.

I suppose if you were operating in a nice, clean, paved pond somewhere with no other craft you'd be safe, but that's pretty hard to find around my parts.

I've got a video camera that I'll be mounting in my Typhoon, but it will be mounted just under the waterline with the antenna in the sail. I know that I'll loose signal once she submerges, but until then, I'll see everything that's under there, without needing to worry about tangling my expensive toy in somebody else's expensive toy.

[ramius-ii]

As a contribution, here is

As a contribution, here is some info that might be useful. For Germbrat, the device you are suggesting is called a "repeater" and the electronics necessary can be rather cumbersome. You might look at some form of acustic coupling then go to R.F.

Rule of thumb is the lower the frequency, the better the results. 2.4 GHz is the worst frequency as this frequency is mostly absorbed by water. 1.2 Ghz or 900 MHz is a better choice. For me, I chose 1.2 Ghz as the antenna size is smaller. At this frequency an antenna is 1.6" long. What's great about this size is you can construct an antenna with gain! An antenna that would give 2.8 Db of gain (every 3 db is like having twice the power) would be 4.8" long. Just perfect for the sail of a Typhoon.

Best, Ed

[roboticsubs]

I tried putting a 2.4

I tried putting a 2.4 Ghz wireless video camera in a submarine and it wouldn't even transmit when it was just below the surface. It was not a very high power transmitter though. Now I am just building a tethered sub with a regular home video camera camera inside and that gives much better results (in my current shallow water tests anyway).
As far as I know, running a cable to the surface is the only reliable way of receiving live video from your video camera on the sub. But check it out, I might be wrong.

[ramius-ii]

Hi RoboticSubs]

[color=#000000]Hi RoboticSubs]

[akulaii]

Hi Ramius-II,

I can give you

Hi Ramius-II,

[quote]I can give you a design that will give you some gain. You might consider a lower frequency like 900 or 450 MHz. In a few weeks I should have my transmitter back from being converted and I can post some results for 1.2 GHz at 3 watts.

I have interest in useful antenna designs. Appreciate your advice in antenna design in 1.2GHz and 900MHz frequency.
Especially an extension design to the surface.

Thanks
AkulaII

[ramius-ii]

Hi AkulaII]http://www.subcommittee.com/forum/icon_wink.gif

Start stacking sections,

Hi AkulaII]http://www.subcommittee.com/forum/icon_wink.gif[/img]

Start stacking sections, connecting the center of one section to the shield of the next and so on. At three sections, you will have about 2.8 Db of gain over a dipole. At 3 Db, it is like twice the applied power. So, if you have a 3 watt transmitter, the antenna will treat you signal as if the antenna were a single wire connected to a 6 watt transmitter! Be sure to check the SWR (Standing Wave Ratio) to be as close to 1.1:1 as possible (that is , you may need to "tune" your antenna a little).

Best, Ed

[interpol]

Also, don't forget that the

Also, don't forget that the lower the frequency you use, the larger the antenna will have to be. But, unfortunately, 2.4 and 5.8 ghz really don't push through anything that well.

I think that 900Mhz, or 1.2Ghz is probably your best bet.

Just make sure that if you are using a 3 watt transmitter, that you have an operator's license for that much juice.

[roboticsubs]

"We would also like some

"We would also like some sensors or even GPS if it even works underwater."

About the use of GPS or sensors on a sub...

If you really wanted to go high tech you could probably have three or more underwater pingers located around the area you are exploring with your sub. Each pinger would output a different frequency. Your sub could orient itself by these pingers. I don't know if there is a commercial contraption like this avaliable or not. You might have to build it from scratch.....which of course would require quite a lot of electronic knowledge.

If anybody has any information on something like this I would be interested.