engsol wrote:


Dan,
I did a study for a light aircraft collision advoidance device.
It worked on transponder pulses. If your craft's speed and heading are
known, the math to resolve the "taget"'s bearing, range, speed and
heading isn't that difficult, otherwise it *is* pretty difficult.
Norm B

But don't the transponders on aircraft tend to transmit that information
themselves?

What I was contemplating was a system that just used the other guys radar to
illuminate (and thus to allow a plot) of (possibly multiple) third
parties.... I don't think it is in general possible to come up with a
really good solution without knowing the bearing and range to the radiating
vessel, but with several ships in the area it may be possible to solve for
the radiators position using the returns from the other vessels?

Humm, thinking about it, you can plot bearing to third parties without
needing to know where the radiating vessel is, and you can plot total trip
length if you can get a good lock on the radiators prf which means that IF
you can see several ships using the scatter from any given transmitter then
you CAN in fact locate that transmitter in most cases.

Even without knowing the transmitters PRF, you can get path length
differences from each of your scatter sources which given a sufficient
number of sources (three or four I think?), could resolve the transmitters
location?

I am not sure that the processing required is a power saving over just
running a magnetron and PFN!

Still, given a decent software defined radio RX board and a couple of
downconverters from 9Ghz, it might be fun to play with.

Regards, Dan.