Police Radar

[sol]

As most of us know the GPS shows a different speed to our Vehicle speed.

Does the Police Radar show the GPS speed or the Vehicle speed

       

[l0ckym]

Most speedos are out, and by law have to indicate higher than actual speed.  So the needle is on 100, but the actual speed is 96.

In terms of what the coppers measure - they normally use LIDAR which is radar, which shoots a beam towards your vehicle, which then bounces back.  The device does this over and over again (many times a  second) - it calculates the time it takes for the bounce to come back, which they can then calculate your speed from.

So in answer to your question - is it your speedo or the GPS - the answer is neither, however it is generally accepted that the speed shown on your GPS would be a truer representation of your 'actual' road speed.  Its this actual road speed that the LIDAR device will measure.

As always, no promises - and this is not advice.  Drive past a copper as fast as you like...

[D4D]

There is also some conjecture about using GPS to determine velocity. Depending on the GPS it can lock on 4 or more satellites. The speed measurement is a mathematical calculation derived from the position change of your vehicle relative to it's last position and the lock on the various satellites. The radar method as mentioned above is a more accurate measure of your speed than GPS as it is taken from a single calibrated reference point. Due to this difference you won't get off a fine saying 'my GPS said I was doing the speed limit'.

[speewa158]

The new toy of choise seem to be Number Plate Recognition . l saw it in action on the Hume South bound at Broadford last week . The beam scans the plate & budda bing , budda boom it spits out   a list of all the things the owner of the car has out standing . Then a nice man with pale blue shirt & a Glock will ask you some questions , & may invite you to pop back to the Poilce station with him . There were 5 cars parked on the side of the road & a tilt tray was loading up . Some there had a good day out others didn't 

[Azz]

I watched a news report online about the launch of four new police cars that have this tech onboard and operational while driving along.

Takes about half a second to identify the rego, owner and and any outstanding fines, warrants etc etc.

In the report they are driving along Kings way and go past a parked car and the officer reads off the screen that the owner of the car owes the State government $98,000.00.

Amazing tech. So make sure you pay your fines!!!

The van is quite often in Bairnsdale working in conjunction with the Sheriffs dept.

[UIZ733]

As most of us know the GPS shows a different speed to our Vehicle speed.

Does the Police Radar show the GPS speed or the Vehicle speed

       

I would hope, the correct speed.

[sol]

I would hope, the correct speed.

    me 2

       

[Tim - Stratford]

The van is quite often in Bairnsdale working in conjunction with the Sheriffs dept.

....and just down the road to the west a bit. 

The recognition cameras are brilliant. The new 'Smart Cars' that have been rolled out in Melbourne have these onboard too...a bit behind some other States.

The Radars and Lasers used by police are all calibrated regularly (and considered accurate by the Courts)

[speewa158]

....and just down the road to the west a bit. 

The recognition cameras are brilliant. The new 'Smart Cars' that have been rolled out in Melbourne have these onboard too...a bit behind some other States.

The Radars and Lasers used by police are all calibrated regularly (and considered accurate by the Courts)

You lot are taking all the fun out of now      Keep up the good work 

[Jeepers Creepers]

We use a thing called a Hillspeed in both cars. (Serious...  )

Say ya set it for 100, at 103, two red lights flash while a buzzer goes off and the readout is bright and easy to read.
They cost around $180.00 each, but since buying them, we've only copped one fine. me.... 78 in a 60, because i forgot to press one button to set it at 60..... bugger it.

Before that, rolling out my speeding fine history was like chasing a runaway toilet roll.

[treads]

Radar (RAdio Detection And Ranging) uses doppler shift to detect the speed that an object is travelling towards or away from the antenna. Their calibration is checked by the operator, using tuning forks, at the start of every shift. The units mounted in police vehicles can be used both in mobile mode and static mode. Hand held radar (like laser) can only be used whilst stationary.

In mobile mode the unit is not only detecting the speed of the target vehicle; but also that of the police vehicle. Most police use the radar in 'fastest' mode. In this mode the display on the radar will show the target speed, the fastest target speed and the patrol speed. The main target speed is that of the biggest object, the fastest is pretty self explanatory and the patrol speed is that of the police vehicle.

In static mode only the target and fastest displays are active. Hand held radar units only have one target display screen. Laser speed detection devices show both speed and range.

In Victoria the radar and laser units have a +/-2kph tolerance range, and thus a person driving a vehicle travelling at say 111kph in a 100kph zone would actually get a PIN for 0-9kph over ($180/1pt), instead of the original 10-15kph over ($289/3pts).

I'm not sure about how other states do theirs.


oh, and mobile/fixed speed cameras have +/-3kph tolerance

[evans52]

My question would be if I'm travelling at the speed of light and turn my headlights on, would they do anything?

[koshari]

My question would be if I'm travelling at the speed of light and turn my headlights on, would they do anything?

You need to google "relativity"

Sent from my SM-N9005 using Tapatalk 2

[speewa158]

My question would be if I'm travelling at the speed of light and turn my headlights on, would they do anything?

ln just which rig will you be traveling at said same speed & will the CT still be touching the road  .
                                                   Dreaming                      

[evans52]

This.............as a note I Googled "lamborghini towing a camper". I also Went to Wikipedia and searched "relativity". As soon as I read the first line, "This article is about the scientific concept......" I drank my beer and said **** it.

[sol]

So we can't go on what the GPS reads or the Speedo.
Going on what the speedo reads would be safer

Some interesting replies here too. Thanks. 

       

[Bird]

As most of us know the GPS shows a different speed to our Vehicle speed.

Does the Police Radar show the GPS speed or the Vehicle speed

       

which ever makes them the most money

[markg66]

Followed a candy car today in Morayfield that had this proudly across the top of the back window with each capital letter in a hi-vis colour
"Automatic Number Plate Recognition"

[Hairs]

When my speed reads 100kph, the gps says 98kph.
So hopefully I wont see Radar.

[SambOz]

They are calibrated by the operator, using tuning forks, at the start of every shift.

Correct me if I'm wrong but I understood the accuracy of the RADAR was checked using a tuning fork, not "calibrated" as such ?

[treads]

Correct me if I'm wrong but I understood the accuracy of the RADAR was checked using a tuning fork, not "calibrated" as such ?

Yep, I realised my error and edited my post two minutes before you replied 

They are calibrated every year and checked every shift

[berlitza]

When my speed reads 100kph, the gps says 98kph.
So hopefully I wont see Radar.

lmao classic, someone has a little bit too much time on there hands

[03GV]

The RAA south australia's version of the RACV/NMRA have said from the testing they have done, that GPS's are accurate and they will show all modern cars as under true speed because all new cars are made a few km's below from factory. But don't ever say to a police officer the GPS said such and such speed because it won't hold up.

[Rumpig]

my vehicles speedo and my GPS both read exactly the same speeds 

[NewieCamper]

I know the speedo read out is over, and also changes a little with tyre wear. I've had several cars and tested the speedo on the 5km test sections on the F3 (M1 motorway) all of the cars tested had been out by about 5km/h at 110.

The GPS on the other hand measures the distance between two points recorded, then averages that out to display my speed. Because the GPS is measuring every second or so, I'll take the accurate speed as the one one the GPS. When I set my speed by the GPS I'm surprised at the number of cars that are travelling slower on the highway.