Distance Limitations of Radar?

[MNCopper]

We haven't gone over this part yet in our coursework, but is there a limitation on the distance the different radar variants have as far as acurracy?

Using a simple math equation it is easy to figure out for every movement of a handheld you will be off by X-inches @ Y Feet.

But is there any merit to the claim?
ie:One example, are you trained to wait until unit is XXX feet away until you record the speed?

I thought I saw a ruling on it, but wanted what others have found, experienced, etc.

Thanks.

[gotthblues]

We haven't gone over this part yet in our coursework, but is there a limitation on the distance the different radar variants have as far as acurracy?

Using a simple math equation it is easy to figure out for every movement of a handheld you will be off by X-inches @ Y Feet.

But is there any merit to the claim?
ie:One example, are you trained to wait until unit is XXX feet away until you record the speed?

I thought I saw a ruling on it, but wanted what others have found, experienced, etc.

Thanks.

well in oklahoma we arent required to have all the math and equasions, and what not, if we have just a few simple requirements and articulation, we are good to go.
i had a stalker in my last car, i had picked up cars two miles out, would i write that and go to court on it,,,hell no, i had no idea what the car looked like,
i was coming back from a trip on a two lane hwy, and would hit cars on hilltops way down the road, no others around. but again, i have no idea what kind of car it was till it got close,
on your hand held stationary radars, the only thing you really have to worry bout, is the angle that you hit them at, the greater the angle, the slower the speed that your radar reads. but that doesnt hurt you, if just gives the driver and edge, you may show them at 50, but the are realy doing 56,,.

[PTI]

The thing you would need to do first off is figure out your radar beam width at a certain distance. You will need to know what angle your radar unit's beam is. Most are between 11 and 18 degrees. Once you know the angle you can punch in the info into a scientific calculator and it will give you the width of the radar beam at any distance you choose. The formula is 2 X Distance X (tangent of 1/2 the angle) {2XD(tan 1/2<)} The radar unit I use has a 12 degree angle and I know at 1000 feet away the beam is 212 feet wide. If I had a handheld unit, being off a couple inches would not affect the area the target vehicle was.

[DaveNT]

The mobile radar units fitted to our vehicles are certified accurate +/- 2 KPH over a distance of 1.1 Ks (mobile mode). We are trained to get a visual on the suspect vehicle, then a clear dopler tone for 3 second to lock on.

We tend not to use these units that often in the stationary mode, preferring to use the hand held lazer units with a similar range, these units record the speed and distance, we dont have to track the target for any set time.

[APDSgt]

The radar will display the same speed whether the car is 100 feet away or 1 mile away. (Maybe I don't understand what you are asking)

Secondly I do not transmit with my RADAR until I can visually estimate a cars speed - I can see a car a mile away but I can not accurately estimate it's speed.

[acreature]

^^what he said

[Bigg Dogg]

it all comes from experience behind the wheel with your radar.Everyone is diffent.I actually prefer the old MPH Trooper models.I had one that could pick up a speeder almost 3 miles out.I have had new radars that would pick up a car as it was passing!!I have had good,I have had bad.The one I have now is a genesis II and it is pretty good.As far as the distance,I use whatever distance i can definantly say that car was the car the radar was tracking.Most of the time I can come within a couple of MPH without the radar.the radar just verifies the speed for me.That just comes from experience.

[tbear853]

I work back east, but I found myself wondering what it would be like working moving radar on some stretches of West Texas highways this year when we were out there, 20 miles and not a nother vehicle met or following ... just endless vistas.



There is no reason to be too worried about range, after all ... the proper use of police traffic radar is to supplement, to back up, to quantify that which you have already observed with your eyes and after you have visually estimated the speed.

I have no doubt that radars like my Eagle or even the older KR-10sp and KR-11, Hawks, even the X band MR-7 ... would read a car at 2-3 miles if terrain were right ... but there is no one here who can estimate the speed of a vehicle like a car at that distance unless it's traveling at extraordanary speeds.

75 in a 65? Forget it !

85 in a 75? Again, forget it!

130 in a 65 or 75? Maybe so.

The upside is that they can't tell it's a police car either at those ranges ... so wait until you can see them much closer, after you've had a few moments to watch and form an estimate ... before you hit that hold button.

As far as the radar signal is concerned ... it travels on indefinately forever unless its refracted, reflected, or absorbed.

[SS396]

As we all know the range is miles long but you have the sensitivity control to filter out how far away you are going to pick up.... I've used a Stalker moving Radar but I really didn't care too much for it, besides it wasn't permanently mounted and had way too many wires.... All of my Radar was done stationary either with a Tomcat handheld or a Decatur Hunter (tried the Mph and didn't like them.) My visual distance was probably 1/4 mile out (depending on roadway) when I started my visual, and anywhere from 250 to 500 feet when I'd engage the radar... Any distances farther than that there is no way to be sure that the vehicle you want is the only one within the zone of influence... Our traffic court was a big stickler that there be no other vehicles within the ZOI or if there was that you be able to articulate through your estimation that the vehicle you clocked on radar was the same one you summonsed.... If you're doing stationary and you try to really go any further you are going to have to turn the radar way off to the side which will lower the speed you get, good for the speeder though... Remember for every 100' the beam is an approximate 22' cone....

[ofoster]

I work back east, but I found myself wondering what it would be like working moving radar on some stretches of West Texas highways this year when we were out there, 20 miles and not a nother vehicle met or following ... just endless vistas.



There is no reason to be too worried about range, after all ... the proper use of police traffic radar is to supplement, to back up, to quantify that which you have already observed with your eyes and after you have visually estimated the speed.

I have no doubt that radars like my Eagle or even the older KR-10sp and KR-11, Hawks, even the X band MR-7 ... would read a car at 2-3 miles if terrain were right ... but there is no one here who can estimate the speed of a vehicle like a car at that distance unless it's traveling at extraordanary speeds.

75 in a 65? Forget it !

85 in a 75? Again, forget it!

130 in a 65 or 75? Maybe so.

The upside is that they can't tell it's a police car either at those ranges ... so wait until you can see them much closer, after you've had a few moments to watch and form an estimate ... before you hit that hold button.

As far as the radar signal is concerned ... it travels on indefinately forever unless its refracted, reflected, or absorbed.

I do live and work the "West Texas Highways, some times you can see for about five miles. Some times the radar will pick up a car at a great Distance (2-3 Miles) but it depends on alot of stuff like terrain, time of day even seems to factor in. Also the wind speed out side can efect your distance, I love it when people argue with me and say "when I came passed you I looked and I was only going x miles of hour". I tell them I saw you way before You saw me.

[tbear853]

Ofoster ... then you probably recognise that stretch of highway in the picture. It's Hwy 90 somewhere west of the Pecos ... well west of it.

It is a small world though, even out there.

Through the '50s we lived in Del Rio, then moved back to Va. and in the '60s and as late as '72, we visited back out there once every several years. This past May, the wife had never been west of Talledega, Al. so we lit out ... and after leaving Langtry, we stopped next in Dryden, Tx and I walked into a small tourist info shop (come to think of it, there were a couple Border Patrol and TDPS cars / pu trk there at a cantina almost next to it, but wife was feeling a little under the weather so I didn't go in), and struck up a conversation with the lady working the desk, she's about 65-70. I mentioned Del Rio and she said she used to live there way back. Turns out that she knew the Finneys that were friends of my parents and she recalled my mother. I got my cell phone out (Verizon worked), and called mom in Va. ... explained and gave the ladies name to her, and Yes ... she recalled her. Said that they both used the same babby sitters (Mr's Finney).

So you just never know who's gonna show up around that next corner .................

Maybe we'll pass this year, if plans work out ... we're cominmg back for a visit (our last one was cut short, wife developed panchriatitus again across west Texas, she wasn't feeling good then in Dryden ...
... then the next night, I took her to the hosp in Alamagordo NM )