Can you elaborate on the factors of the weather affecting radar? I know each judge used to ask how the weather was and if it was a clear day on a radar ticket, and you didn't see too many police running radar in the rain or bad weather. Today, state cars run radar in just about any weather including heavy rain. A lot of them have gone to lazer but I still see some of the older units being run.
I've talked to some of them that have said they just didn't want to run radar in the rain to avoid standing out there writing a ticket but I've always felt there could be some discrepancies in the readings with foul weather.
Explain more how that works please. I'm trying to comprehend how the readout is showing two at once...are there two numbers on the unit? I know a little more how the lazer works (I think) but how do you tell which it's picking up on the radar unit?
predominantly its fog that causes interference. humidity in the air decreases the propagation of the radar microwaves so the signal reaching the radar unit is weaker under foggy conditions and therefore less reliable.
K band which is the most common band used which is usually (24GHz) which is near the frequency of water vapor which is around (22GHz). my own personal radar unit uses KA which is a more advanced band but most use K band. This effects pickup but does not necessarily affect the accuracy of the radar itself. the cop MAY not pickup up an earlier signal since the water vapor absorbs the output signal and return signal.
but you also have to remember that a cop when running Radar has to visibly track the vehicle as he confirms it on the unit itself. Radar units have a doppler signal that gives a higher pitched signal with increased speed so its really (3) things goin on. the visual of the vehicle, the visual of the unit and the audible of the doppler.
when rain and fog are present its nearly impossible to watch the vehicle which of course you wud have to do cause you have to decipher between which vehicle you are tracking. if the Radar unit has same lane technology it will only track the vehicle goin in one direction. on most roads u have vehicles going say north and south. if u have same lane technology u can turn off the southbound lane for example and only monitor the northbound traffic lane.
without this it becomes very difficult to decipher if the vehicle ur Radar unit is tracking is coming towards you or going away from you. it will track both if u don't have this technology. of course if its a one lane road with vehicles goin in only one direction then it doesn't matter but thats pretty rare.
so weather absolutely affects the validity of the use of radar and can and shud be contested in court if a ticket was issued during poor weather.
a cop is able to receive an earlier signal on a cold night wen no atmospheric moisture is present. In colder temps there is less moisture in the air unlike hot weather therefore wen its cold the Radar will shoot much further.
if the cop is using KA band it can pick up vehicle up to 5 miles away. I have a friend who is an Oklahoma Trooper and says he picks up trucks for several minutes before he can even see them. he won't write till he can track but its pretty amazing how far they can reach on a flat stretch of road with no dips in the road.
as far as FASTEST lane and CLOSEST lane technology basically there are three windows in a unit capable with this. the third window is ur target speed window. not all units have this tho. many don't cause their more expensive.
older radar units without this technology wud simply pick up the vehicle with the largest mass. now it can pick up the vehicle that is closest and which is fastest. when the fastest vehicle becomes the closest vehicle the windows switch and the fastest becomes the closest so yes you can track two vehicles at once but I wud never issue two tickets at once cause its pretty hard to stop two vehicles at once. I wud simply stop the one goin fastest even if the other was above the posted limit.
ppl often say what about the other vehicle that was speeding.... I tell them sorry I can only stop one at a time and its YOU that was going the fastest.
I believe radar is designed to be most accurate when reflected off of a license plate. Isn't the nose shape of a sport bike sometimes a little more difficult to get a quick accurate reading if shot head on?
radar doesn't reflect off a plate. it reflects off the vehicle itself. the nose shape of a motorcycle does make it a little more difficult to get a reading but thats more reserved with laser cause the MC is a smaller mass therefore harder to point the red dot on a laser unit on a MC.