Can a Radio Wave Camera Be Used to Track Wildlife in the Field?

[peteypete]

I work in wildlife science. I track radio tagged animals, and am wondering if it's possible to make a radio wave camera, that can detect and visualize radio waves on a screen. I could use this camera to see the source of a radio signal (i.e. which bush or tree an animal is hiding in). This would be much easier than trying to guess based on my directional antenna and radio receiver, which only gives me a general direction. I'm guessing that I would need a very wide "lens" for radio waves, but I'm just curious if this idea makes any sense at all. I'm obviously not very savvy on this topic.

thanks

 

[Dale]

Sure, that is what radar is.

 

[skeptic2]

In order to get an idea of what is possible or practical could you tell us the frequency, manufacturer of your equipment or at least the length of the driven element of your antenna? I presume you're using a single yagi antenna (a series of vertical elements along a beam) and look for the strongest received signal strength. Is this correct?

It sounds to me what you're asking for is a small video screen, perhaps showing the scenery using a video camera with a radio image overlaid on top of it. While I don't think this is impossible, one consideration you should be aware of is the more you want to localize the source, the larger your antenna or antennas have to be. You can reduce the size of the antennas by going to a higher frequency, but the higher the frequency, the poorer it penetrates foliage and the more it is blocked by intervening objects.

 

[russ_watters]

Welcome to PF.

You're describing RADAR. But you need radio waves to be bouncing off of objects in order to create a picture. You don't have that - all you have is point sources. So your picture would only be a small handful of dots.

 

[Archosaur]

Also, the longer the wavelength you're trying to observe, the larger your "resolving angle", which is essentially how "smeared out" an image is. In order to get a decent picture, you'd need something much bigger than a conventional camera.

Something, say, this big:

[PLAIN]http://learn.uci.edu/media/OC08/11004/OC0811004_RadioTelescope.jpg

 

[peteypete]

Thanks for the replies!
Skeptic2, that's exactly what i had in mind. I do use an H-antenna, it's about 65cm from end to end, and the frequencies are around 218 MHz (some are at ~160 MHz, but those use slightly different sized yagi). I had a feeling that Archosaur's radio telescope is what I'd need. Obviously not very practical in the field. I don't need any imagery of the surrounding area -- I would be fine with just a dot, but it sounds I'd need a huge antenna to get usable resolution.
Out of curiosity's sake, if I managed to make some kind of big collapsible antenna, would the rest of my portable radar screen contraption be difficult/expensive to make?

thanks again!