(meteorobs) General OT question....RADAR accuracy.

[Pat]

I think I would be a good one to answer this as my work experience is in this area...
It obviously depends a lot on the radar frequency, Pulse repitition interval, and scan rate.

Luckily the NWS doppler radar network is very good at this and is at a good frequency to pick up meteorites in terminal flight. Airport radars are at a little bit too big a wavelength (low frequency) to pick up small objects. But the NWS doppler radars are tuned to pick up hail and water droplets in both size and direction of travel. They are also working all the time and cover most of the US quite well. So we should try and get in good with our local NWS operators. The only problem is their scan rate is a little slow to "track" much of the flight so you tend to get only one or two returns on the entire path. With any radar you never really get the entire path - you get points where an object was at discrete times...it may be seconds or minutes between these times based on the type/setup of radar. So you do not "see" an explosion for the most part.

Yes many military radars are good at this. They tend to operate in the K (Ku, Ka, K) bands which represent the 1 to 10 cm wavelenght and is good for objects between 0.5 cm and above. The problem is they are rarely observing a particlar area and getting data from them is difficult at best.

Now if you were to design a radar to specifically do this you would want one that scans a large area quite frequently with a fairly short wavelength (since you are less concerned about rain/fog attenuation).
You would like a tracking radar (not many civilian ones do auto tracking of detected targets).

All that being said, I think your best best is find out how to get your local NWS doppler radar data so you can call and tell them not to delete the data when an event happens. With luck you can get two returns. Now if you have money and want your own solution there are a number of aircraft weather radar and microwave auto landing systems you can purchase which might do the job. For a few thousand dollars you can get a radar you can point in a direction and set the parameters you want and record the data (sort of like a sentinel camera) and you might get multiple points on a track (with time tags) if a meteorite passes in your FOV. The good thing about this setup is you only need one station since radar gives you distance to object in addition to speed and position. It is also good in that it tracks the terminal flight parameters giving you a more accurate position than triangulating two visual paths of high altitude flight.

An even more accurate set-up would be using a laser range finder setup. They can scan the entire sky very fast (so they get most of a bolide track), and they are very accurate in distance as well as azimuth and elevation. The problem with most of these are the short range (5 miles is pretty hard to get). Also if you go over class 1 then you could be blinding some pilot and get in trouble with the FAA. There are green eye safe lasers, but I don't know of any for civilian use that would get you the range.