1. ## 2D instead of V1 Arrows ?

Maybe this is a stupid question but I was wondering if you can equip the car with three independent antennas and use them to project the information on a two-dimensional matrix by triangulating. Kinda like a real Radar installation signal strength and relative position should allow this or is the a problem with that ? Kinda like connecting 3 V1s and evaluate their directional input. Now that would be cool if you could actually see the threats on a screen relative to your position, I can't be the only one thinking about this ? Anybody got any ideas ??

2. Now that you mention it it's kinda surprising that this isn't available for the high-end market like exotics and ultra-high performance (and ultra expensive) cars.

3. You'd need the antennas much farther apart to get an accurate triangulation.

With antennas on a car (or a V1 type unit), you could get the direction to the source but not the distance. Distance measurements requires a known timing reference; in other words, you'd have to emit the signal that you're measuring. That's how "real" radar (and police lidar) works. It times the return time of its own signal, so that it can calculate distance and location.

You could determine distance if the source is between the antennas, but that would require the radar gun to be inside the car. Guess that won't work.

4. Originally Posted by kpatz
You'd need the antennas much farther apart to get an accurate triangulation.

With antennas on a car (or a V1 type unit), you could get an approximate direction to the source but not the distance.
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Approximate would be good enough don't you think. Seems the V1 (with very little distance between the two antennas) is accurate enough for many people so even if it is not 100% accurate it might allow some sort of orientation.
If you have a direction then you an use this to determine an approximate position (direction of each measurement) by signal strength and frequency shift (Doppler effect). Since there are only so many manufacturers of Radar guns, it should be possible to determine average output per device. This can also be further enhanced by the fact that many devices operate on a different frequency. Once a signal is identified you could also use approximations to determine the relative position even if you lose contact or you cannot handle as many signals. It is not like we want to guide a plane with this but would be useful, especially with a HUD so you can track them while driving. Once this system is developed there would be endless possibilities with GPS and peer to peer signaling...

5. Determining distance by signal strength won't work since there are too many variables to consider - line of sight, objects blocking or reflecting the beam, curves, hills, moisture in the air, etc. You can see this with the wide variation in alert distances/strengths under different conditions with your existing detector.

Using the Doppler shift would require that you know the original (unshifted) frequency. Even if you have a database of known radar gun frequencies, there's enough variation from one unit to the next to make this approach impractical. Much like determining distance, you need to be emitting the signal you're measuring in order for speed or distance to be determined.

Now here's something that might work. If your detector has a rotating antenna (like airport and boat radars have), it can more precisely determine direction. It might even be able to measure YOUR speed based on the doppler shift using reflected signals as a reference. Then if multiple detectors communicate via some sort of wireless link, and multiple detectors are picking up the trap from different directions, those multiple points of reference could be used to triangulate the location of the trap. Combine this with GPS and you could determine the exact location and distance to the trap. Of course, it wouldn't work so well if you're the only car in the area with one of these AWACS style detectors.

6. Tough problems, you are right. How about we agree on flat terrain as no detector has a good chance with a hilly terrain. Humidity..etc could be done during self calibration. If it was a big issue a Laser (maybe attached to the Radar cone) could be used to measure the terrain, would be FCC and FDA ok I think.

How does the Radar gun know it is picking up the correct signal and not the microwave in an RV ? After all this would be a good defense if the hardware varies so much...Or a different route would be to go the RDD way and determine the signal the particular models are emitting.
Heat traces and shape recognition on the side of the road might also be an additional option, might be overkill though unless you add a smart gun turret that will take out targets on the road side, not good for people who had their car break down..lol

A rotating Antenna is a cool idea...An active signal would mean FCC problems though I fear. A small cone would allow precise determination of the signal's direction. With GPS the system could learn and recognize the Walmart or whatever and alert of new threats. Now if you were just coming to a new area, the detector could update itself communicating with others about these permanent and harmless signals as well as the real threats. This would require an open standard that all manufacturers can use...

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