FirmamentFX
May 19, 2007, 07:16 PM
Hi guys,
I would be interested to hear people's thoughts about problems they have had streaming real time video from UAV to ground.
As far as I can see, the biggest problem is bandwidth. This is the mother of 'em all, and determines everything that is done.
Encoding/Decoding
Another problem is the actual encoding/decoding methodology. There are many protocols and codecs out there, but are any of them suited to this kind of work? The one that immediately springs to mind is MPEG-4. This has become pretty standard now.
There is also Quicktime and Windows Media (itself an extension of MPEG-4), although these are probably not particularly suitable.
Data Processing
To an extent, it all boils down to what you want to do with the data in the UAV and on the ground. If there are any machine vision / tracking systems on the UAV, then the video feed needs to be split "at source" to go to the onboard systems and the downlink.
On the ground, do you simply want to view the image on a screen (in which case a simple commercial wireless video Tx/Rx unit will do), or do you want to integrate it as part of a bespoke software system (to overlay it with HUD data perhaps, or to process it further, or even to simply record it to a hard disk)?
Multiple Cameras
Finally, there is the multiple camera option. If you have 2 or 3 cameras (perhaps 1 IR for example) on board, you can either a) use a switch control from the ground to adjust which feed is sent, or b) try and work out some way to encode multiple streams in one downlink feed.
If you take option a) you are limited to only seeing/recording one feed at any one time, which may be fine in some cases, but if you were flight testing, you could well want to compare 2 or more camera angles from the ground...
With b) you come up against the problem of bandwidth again, only (at least) doubled...
A long post. My apologies. This is something that has been turning over in my mind lately though, and as I said, I would be interested to hear how others see and approach this problem.
I would be interested to hear people's thoughts about problems they have had streaming real time video from UAV to ground.
As far as I can see, the biggest problem is bandwidth. This is the mother of 'em all, and determines everything that is done.
Encoding/Decoding
Another problem is the actual encoding/decoding methodology. There are many protocols and codecs out there, but are any of them suited to this kind of work? The one that immediately springs to mind is MPEG-4. This has become pretty standard now.
There is also Quicktime and Windows Media (itself an extension of MPEG-4), although these are probably not particularly suitable.
Data Processing
To an extent, it all boils down to what you want to do with the data in the UAV and on the ground. If there are any machine vision / tracking systems on the UAV, then the video feed needs to be split "at source" to go to the onboard systems and the downlink.
On the ground, do you simply want to view the image on a screen (in which case a simple commercial wireless video Tx/Rx unit will do), or do you want to integrate it as part of a bespoke software system (to overlay it with HUD data perhaps, or to process it further, or even to simply record it to a hard disk)?
Multiple Cameras
Finally, there is the multiple camera option. If you have 2 or 3 cameras (perhaps 1 IR for example) on board, you can either a) use a switch control from the ground to adjust which feed is sent, or b) try and work out some way to encode multiple streams in one downlink feed.
If you take option a) you are limited to only seeing/recording one feed at any one time, which may be fine in some cases, but if you were flight testing, you could well want to compare 2 or more camera angles from the ground...
With b) you come up against the problem of bandwidth again, only (at least) doubled...
A long post. My apologies. This is something that has been turning over in my mind lately though, and as I said, I would be interested to hear how others see and approach this problem.