Dear Steve,

Thanx for the reply, but I couldn't well follow that.

Need a little more elaboration from you.

I think the IR idea is more workable than installing a Radar tower, that would make the system bulky and more power cosuming. Where would I recharge the heavy battries on a trip into mountains........uhh.

You said that security IR sensors won't work, Can't we use ordinay sensors those which are normally used with the IR remote controls of the TV etc.

But the IR would also make the range very short.

How about making an RF based system.
Because the IR will always have to be pointing to the camera leaping over my head visible awkwardly and IR will also be visible to my handy cam, a noise in the video ???

Babar/