[darkpuppet]

sure you may worry about GPS tracking devices an whatnot, but sometimes they can prove invaluable evidence to help you..

from this arstechnica article..

Quote:Accused speeder to cops: My GPS proves your radar gun is wrong
By Ken Fisher | Published: October 26, 2007 - 10:27AM CT

GPS-based tracking devices don't just help you figure out where you are and where you're going, they might also help you avoid a speeding ticket. Shaun Malone of California is contesting a speeding ticket in that state by arguing that his GPS-based tracking system shows that the officer's radar gun was wrong.

Malone, a 17-year-old who was clocked doing 62 MPH in a 45 MPH zone on July 4 of this year, has more than just a GPS on his side. As the AP reports, his stepfather Roger Rude is a retired sheriff, and is pushing Malone to fight the ticket. (As an aside, how awesome would it be to be Sherriff Rude?)

Ironically, Malone's parents had the GPS system installed in order to track the whereabouts and speed of their son, whom they readily admit has a lead foot. In fact, he has already been grounded for having gone over 70 MPH after the GPS was installed. Nevertheless, Malone's parents say that the data on the day in question shows that their son was not speeding in the vicinity of where the ticket was issued.

While many GPS systems don't log travel details extensively enough to be used as a defense against a moving violation, Malone's car was outfitted with a device that could do just that. According to Rude, all recorded plots on Malone's route show him to be driving under the speed limit. At the same time, Rude says, GPS-systems are clearly more reliable than radar systems, which, while good, are "not an infallible tool" and are subject to human error.

A Sonoma County traffic commissioner has to decide whether the GPS system can be accepted as a basis to challenge the ticket, but ex-sheriff Rude is prepared to push his case in court in the event of an unhappy outcome.

The debate is likely to come down to how often the GPS device calculated and reported ground speed. Petaluma police lieutenant John Edwards told the AP that since GPS is satellite-based, there's a delay involved, and that Malone may have sped up and slowed down in the window between measurements, which could be as long as 60 seconds.

GPS tracking systems like the one in Malone's car are becoming an increasingly popular way for parents to keep tabs on their kids, an outgrowth of the initial use of such devices in car fleets and trucking. Many consumer-oriented GPS navigation systems also have these capabilities, but Malone's was hardcore: the system would even e-mail his parents in the event that he drove too fast.

[naz]

that's a slippery slope.. if that becomes court admissible infallible evidence they would subpoena him for the rest of his gps logs and give him a citation for every time in the past he violated the speed limit because they would have proof that he was speeding

also there are tons of calibration and other issues associated with that defense.. the same arguments that apply to get out of speeding tickets could be used to argue why that is inadmissible as proof

bet you it was something like the gps lost signal and interpolated speed based on distance covered over the time the signal was lost.. if the the kid was stopped already that would lower his average speed

[Flofocus]

I dont tink the delay is 60 seconds though. Mine sure isn't....I flore it, and it goes up quickly, there IS a delay but no where near 60 secodns, I'd say 5 seconds MAX.

[Frost__2001]

I've heard of that modified GPS things about parents doing this with their cars on a few american news reports on NBC, CBS & ABC over the last year or so... I think it's a good ideal that they are fighting the ticket in court over this, as it shows once again police are out of touch with tech, yet again.

[NefCanuck]

Hrm, I dunno, the problem is that GPS systems have failings just as radar guns do (and laser guns, despite the manufacturer claims otherwise)

This could likely turn into a "My system is less wrong than yours is" type of thing <_<

But admittedly, the trial would be fun to watch ;)

NefCanuck

[ZX5focused]

we sell this type of gps system at Canadian Tire. the information has to be downloaded after the fact onto a computer.

[naz]

Flofocus,Oct 26 2007, 06:25 PM Wrote:I dont tink the delay is 60 seconds though.  Mine sure isn't....I flore it, and it goes up quickly, there IS a delay but no where near 60 secodns, I'd say 5 seconds MAX.
[right][snapback]251788[/snapback][/right]

but if you are really wailing on the car the 5 seconds delay would be a big difference in speed.

those gps just aren't calibrated tightly enough to be used in court. its better to use the traditional defenses against speeding and go from there.. trying to attack the calibration of the officer's devices or his/her training and trying to bring reasonable doubt that you were not violating the vehicle code

[SmokeBCBuDZ]

GPS updates position and speed every second.

[naz]

SmokeBCBuDZ,Oct 26 2007, 11:25 PM Wrote:GPS updates position and speed every second.
[right][snapback]251805[/snapback][/right]

depends which device you have and whether you have signal from enough satellites to triangular your position

which device do you have? i've tried a couple and they aren't super accurate all the time.. enough to navigate around but not enough that i would try to use is as evidence in court to contest a speeding ticket

[NefCanuck]

naz,Oct 26 2007, 06:29 PM Wrote:

SmokeBCBuDZ,Oct 26 2007, 11:25 PM Wrote:GPS updates position and speed every second.
[right][snapback]251805[/snapback][/right]

depends which device you have and whether you have signal from enough satellites to triangular your position

which device do you have? i've tried a couple and they aren't super accurate all the time.. enough to navigate around but not enough that i would try to use is as evidence in court to contest a speeding ticket
[right][snapback]251806[/snapback][/right]

Depends on how many satillites are fixed on the GPS as to the accuracy... I think the most I've ever seen locked on my GPS at any one time is ten. That would give you a pretty damn close reading esp at the one sec intervals I have mine set at...

NefCanuck

[Frost__2001]

NefCanuck,Oct 26 2007, 11:57 PM Wrote:

naz,Oct 26 2007, 06:29 PM Wrote:

SmokeBCBuDZ,Oct 26 2007, 11:25 PM Wrote:GPS updates position and speed every second.
[right][snapback]251805[/snapback][/right]

depends which device you have and whether you have signal from enough satellites to triangular your position

which device do you have? i've tried a couple and they aren't super accurate all the time.. enough to navigate around but not enough that i would try to use is as evidence in court to contest a speeding ticket
[right][snapback]251806[/snapback][/right]

Depends on how many satillites are fixed on the GPS as to the accuracy... I think the most I've ever seen locked on my GPS at any one time is ten. That would give you a pretty damn close reading esp at the one sec intervals I have mine set at...

NefCanuck
[right][snapback]251823[/snapback][/right]

Yeah I heard the same thing with certen models, and not to mention what services it is registered under. I have heard of some using both satillites and cell towers for greater accuracy.

[naz]

my phone uses both satellites and cell towers unfortunately its still not that accurate.

when i'm indoors and its relying just on the towers the margin of error is especially large

[konafocuswrc]

for those gets not good experience with GPS, it could be installation error..
i mean putting GPS under metal, under the roof, or window tinting that got metallic or relfective, that will not get you a good signal reception..

or it could be really low-end GPS unit..
sometimes, getting external antenna helps a lot..

[naz]

konafocuswrc,Oct 29 2007, 02:02 AM Wrote:or it could be really low-end GPS unit..
sometimes, getting external antenna helps a lot..
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ya that could very well be my problem. i'm using the gps receiver that came built into my LG VX8500 (chocolate) phone

[konafocuswrc]

naz,Oct 28 2007, 09:56 PM Wrote:

konafocuswrc,Oct 29 2007, 02:02 AM Wrote:or it could be really low-end GPS unit..
sometimes, getting external antenna helps a lot..
[right][snapback]251905[/snapback][/right]

ya that could very well be my problem. i'm using the gps receiver that came built into my LG VX8500 (chocolate) phone
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LG is korean company and in korea, they have indoor antenna that is built in any kind of building and includes subway..
so wherever they go, cell and gps function works really good whethere they are in indoor, under ground..

so those GPS function outside of Korea is not really meant to be used as good as GPS unit alone..

Garmin is really great GPS in north america.. and TOMTOM is better in Europe..
GPS unit records how fast they were going but the unit don't show when..so it doesn;t have enough evidence to be used for speeding defense..

[D-Dub]

naz,Oct 26 2007, 01:37 PM Wrote:that's a slippery slope.. if that becomes court admissible infallible evidence they would subpoena him for the rest of his gps logs and give him a citation for every time in the past he violated the speed limit because they would have proof that he was speeding

also there are tons of calibration and other issues associated with that defense.. the same arguments that apply to get out of speeding tickets could be used to argue why that is inadmissible as proof

bet you it was something like the gps lost signal and interpolated speed based on distance covered over the time the signal was lost.. if the the kid was stopped already that would lower his average speed
[right][snapback]251785[/snapback][/right]

You cant charge anyone after they erase their logs....Im sure after every night they d/l the info, read it and delete it.

This kid has a good case, because if it took 60 seconds to relay information then the gps would likely log a lost reception error at the time he was caught.

They use gps for F1 races I cant see it having a delay of that long.

[ZED_not_zee]

WOW this kid and his Dad had better get every piece of scientific evidence to do with GPS and it's accuracy as well as details on there own installation. 6 things are going to happen:

1 the state of California is going to recognize this as a land mark trial that makes case law for the rest of the country...

2 the state of California will pull out every Expert witness they can.

3. the defendant will lose, and appeal

5. the dependent will get a high price lawyer and make it a civil case

6. the state of Califonia will settle and end up with a million dollar piece of case law

7. because thsi Kid didn't do his home work none of us will be able to use it a defense.

[Flofocus]

you forgot 4