GPS in Court

[keatonsdad]

I know alot of us here have used their GPS to verify our speed, but would it be able to be used as a defense in traffic court if need be? Would it be more accurate than the laser and radar that the police use?

 

[jolinc01]

I.m guessing no. Ford police cars have certified calibrated speedometers for "pacing" and pursuits. Also the radars are supposed to be certified yearly. They also come with tuning wands to test the radar each day.

 

[ratdog442]

an A for effort

http://www.pressdemocrat.com/article/20090907/articles/909079980

 

[Frogman]

I don't see it...

Commercial GPS receivers update at 60hz. That's once per second.

Lidar (and conventional radar) is for all intents and purposes instantaneous (speed of light and all that).

I'd put my money on Radar/Lidar being more accurate than a 200 dollar GPS receiver.

 

[SoonerLS]

Commercial GPS receivers update at 60hz. That's once per second.

Last I checked, hertz are cycles per second, so that would be 60 times per second...

 

[Frogman]

You are correct.

I meant 1Hz. Once per second.

 

[n8bachelor]

I would tend to agree with the Frog. Not only are the in-car GPS units less accurate than police radar but how would you use the in-car unit to prove you innocence? Would you have to have it forensically analyzed to determine when and where you were and how fast you were going? That would likely require destruction of the machine. Not worth it to pay a $200 ticket.

 

[remark]

if this kid knew he was being monitored why would he be speeding?
he probably was, just saying...

 

[SoonerLS]

I would tend to agree with the Frog. Not only are the in-car GPS units less accurate than police radar but how would you use the in-car unit to prove you innocence?

Most GPS units are accurate to within 0.1kt (at least according to all of the specs I've checked), so that's not really an issue. The bigger problems are how frequently, if at all, the GPS unit records the data, and how to verify that the data has not been altered. It would be possible to build a GPS device that can do that by writing the data to a SanDisk SD WORM card (which, after all, is designed for that purpose), but I don't know if any do that kind of datalogging.

 

[Frogman]

A lot of them do. Hell, even the factory one in my F450 has a "breadcrumb" function. But you have to enable it, it doesn't do it automatically.

 

[SoonerLS]

A lot of them do. Hell, even the factory one in my F450 has a "breadcrumb" function. But you have to enable it, it doesn't do it automatically.

I know mine (Garmin Nuvi 255W) does route tracing, but the only data I could get off of it was endpoints and arrival/departure times. Average speed is interesting, but I'm thinking it probably won't help if you're trying to beat a ticket...

 

[Mechanicboy]

just get a public defender or lawyer because the judge doesn't even listen to you without one.