Sorry for not lurking any longer before posting but I have a deadline :~)
I am working on a project to develop augmented-reality systems for pilots. We won't be able to utilize real aircraft until our project reaches higher levels of funding so our proof-of-concept vehicle is a small unmanned helicopter.
Our "virtual cockpit" on the ground will have 7 or 8 large monitors wrapped around the pilot. Some will be real video mixed with augmented reality, others will be purely virtual reality.
I need to downlink at least 4 live video streams from the helicopter.
We have decided to use strictly unlicensed frequency bands and have already dedicated 900mhz and 2.4ghz to other vehicle systems. That pretty much means our video transmitters have to be 5.8ghz.
Right now we are planning to use these video transmitters and receivers for video:
That means we will be spending $1,000 on video transmitters and receivers.
Since this is a large community of people who do this type of stuff often, I thought I would ask if anybody here has any better ideas about how I could get that many video feeds from a heli for under a thousand dollars?
Replies
We did consider IP cams, but digital encoding and compression can introduce latency into the video that we wanted to avoid since we plan to eventually pilot the helicopter from this video.
Since the Futaba is on 2.4ghz and the GPS and other telemetry is using 900mhz we decided to try to use the 500mw 5.8ghz transmitters sold by Iftron (www.iftrontech.com).
I attached some pictures showing our vehicle setup and the virtual cockpit inside the van.
Now I'm stuck with video that occasionally sputters. Note the monitor on the bottom-right of the picture - that is the camera looking straight down and in this picture it had momentarily completely lost signal.
I am trying everything to try to clean up our video but I'm not a radio expert. I put a filter on the battery to block noise since all 4 transmitters use the same battery. That increased our SNR by 10db, but the video still doesn't lock up solid, and we get a lot of bleed-over from one channel to another, even though our channels are separated by 40mhz.
Anybody have experience with different antennas for 5.8ghz?
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belly.JPG
virtual_cockpit.JPG
900M seems to mess with some GPS devices, 2.4 kills the new 2.4G RC.
5.8 dies if anything is in the way. (anything includes any parts of the airframe)
You can't use the ham bands for anything at all commercial.
(Commercial is defined very tightly.)
If you doing it as a one off your likely hood of getting caught is low, but it is illegal.
So your best choice would probably be 900Mhz with a big tracking dish and lots of physical seperation from the GPS and a high quality GPS receiver with tight front end filter.
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I've flown that on a rocket with had held aiming to several miles.