How does a radar receiver discriminates its own echo if other radars are transmitting

how does a radar receiver discriminates its own echo if other radars of similar frequency, power and temporal characteristics are transmitting towards it. assuming a case when two radars are facing each other.

The situation like this is typical for jamming. Fortunately, radars usually do not operate at exactly identical frequency, and their antennas have narrow beams so the other radar signal is only getting into the first radar receiver through side lobes.

A normally operating radar, upon receiving such kind of jamming signal, can either move to another frequency, or, use time windowing to obtain echoes within certain range. Radar operator can easily distinguish a jammer by its signature on a PPI display; there are features in modern radars allowing to suppress jamming.

Got a different but interesting question.

Traffic radar uses C/W doppler radar mainly because it's cheap. Also because that is all the FCC will approve. It also has pretty poor freq. control which is actually a PLUS to the traffic radar companies as any radar jammers that have been built to defeat it can't easily pick up these varying exact freq and jam them. Yes , traffic radar jammers are illegal by the FCC and I am pretty sure will never try to build one but how would anyone go about ever jamming such signals? :)

Police cars with the same radar equipt can easily run their radar together without jamming each other so how would this even be possible?

I don't see how

Brute force jamming?

Radar jamming has developed in a quite impressive discipline. You can find many books on it. To reduce jamming by other radars (rather not intentional), each radar should operate on its frequency, use directional antennas and utilize natural environment like installation in small valleys that can protect it from other radars. Pulse coding and other signal features allow one radar to recognize only its own pulses while other ones are rejected in signal processor.

Police radars can use each its frequency; at they use CW signals, it is easier than with pulsed radars. As the Doppler police radar needs only a low power to operate, it does not interfere if other such radars are operated farther than a half mile away. Jamming is only possible if one knows radar frequency and antenna radiation pattern. Most attempts are technically unsuccessful and as well are prohibited by law. Driving carefully is easier and costs nothing; honesty of police officers is then another question.

I find the entire topic fascinating myself both militarily wise and everyday traffic wise. Love stories of the RAF and Luftwaffe night fighting war.

I do drive pretty carefully in fact. I am probably the slowest guy on the road now ! I hate to spend to much money on gas in my old age.

I know what your saying. In fact I know of one instance where a traffic radar engineer was asked to design a system to defeat his OWN RADAR SYSTEM and he couldn't even do it.

that's what makes this particular topic it so fascinating. Not only this but traffic radar detectors and their design.

that actually interests me far more

one thing in particular there

New radar detectors actually have what looks like a OPTICAL LENS ON THE FRONT of the microwave horn

while your in walmart look at the whistler radar detectors

this is what interests me the most

How what looks like a optical lens can work with microwave frequencies !

anyway thanks for the nice reply

I agree with you that microwave and radar technology is wonderful.
Concerning dielectric lenses, they are used widely in microwave antennas. In radar detectors I think it rather makes a transparent cover. Simple horn is good but debris, water and moisture is not allowed to drop inside. The horn-corrected lens is a widely used microwave antenna which achieves a good sidelobe suppression and reduces the aperture size for a good directivity.

thanks again for the nice reply pal.

I think what you say is true in that it's a attempt to use a dielectric lens to increase radar sensitivity myself. Escort radar detector company actually has a patent on such a design.

I go the whole gamut on radar design and it's history, This is only a small part of my interests. :)

---------- Post added at 15:50 ---------- Previous post was at 15:32 ----------

I was reading a popular electronics article once on how to fashion horn antenna's to pick up sound much better and it struck me that the designs were very similar to microwave horns. Also that some of the designs also work for LIGHT reception and transmission.

amazing stuff how they are interrelated.

A more trivial explanation for the optical lens is that some detectors are radar/laser combi detectors.

well some do have this optical lens on their laser receiver section in fact ! :)

We speaking about airplane radars or police radars for car tickets.

---------- Post added at 05:12 ---------- Previous post was at 04:53 ----------

Meanwhile if someone make radar-laser jammer, he can test it with this :

Test your radar detector or laser jammer with this traffic enforcement LIDAR gun simulator
http://www.instructables.com/id/Test...mer-with-this/

---------- Post added at 05:21 ---------- Previous post was at 05:12 ----------

Good link for time killing :

http://forum.e46fanatics.com/showthread.php?t=802688

Thanks for posting this Tpetar. looks like some fun stuff ! :)

Yes my friend, you can find on Internet reflective spray for plate, or light reflextive protection for plate, this make totally white plate when photo is made. I didnt try that.