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Radar Beats GPS In Court — Or Does It?
TechnologyResource writes "More than two years ago in California, a police officer wrote Shaun Malone a ticket for going 62mph in a 45-mph zone. Malone was ordered to pay a $190 fine, but his parents appealed the decision, saying data from a GPS tracking system they installed in his car to monitor his driving proved he was not speeding. What ensued was the longest court battle over a speeding ticket in Sonoma county history. The case also represented the first time anyone locally had tried to beat a ticket using GPS. The teen's GPS pegged the car at 45 mph in virtually the same location. At issue was the distance from the stoplight — site of the first GPS 'ping' that showed Malone stopped — to the second ping 30 seconds later, when he was going 45 mph. Last week, Commissioner Carla Bonilla ruled the GPS data confirmed the prosecution's contention that Malone had to have exceeded the speed limit and would have to pay the $190 fine. 'This case ensures that other law enforcement agencies throughout the state aren't going to have to fight a case like this where GPS is used to cast doubt on radar,' said Sgt. Ken Savano, who oversees the traffic division. However, Commissioner Bonilla noted the accuracy of the GPS system was not challenged by either side in the dispute, but rather they had different interpretations of the data. Bonilla ruled the GPS data confirmed the prosecution's contention that Malone had to have exceeded the speed limit."
If the average speed is 45 mph, and he was stopped at the end (ie speed 0), then at some point he was going above 45. Especially since you can't stop instantaneously. This is like calculus you learn in High School... If the Judge ruled the other way, the future of America would be even in deeper sh*t than it already is.
Last time I beat a speeding ticket in that state... I paid for it dearly. Six tickets for less than 3 mph over the limit in a month. I find, although morally repugnant, it's much cheaper to pay up now and complain later; rather than to invert the order.
The Geek in Black
I know my BCD's (when I'm Sober)
The "average" nature of radar does offer a potentially dangerous way to _not_ get caught: A friend was pressing on and came over the brow of a hill to see a Police officer pointing a radar gun at him. He KNEW there was nothing behind him and stamped on the breaks resulting in him stopping sufficiently quickly that the radar gun hadn't posted a speed before he stopped - adding sufficient "zero speed" into the average calculation meant he wasn't caught speeding. He then calmly, and slowly, drove into the lay-by because he assumed, correctly, that the officer would probably want a quiet word.
Eclectic beats from Leeds, UK
handmadehands.co.uk
I expect sampling as close to continually as possible would make for a tighter defense, 30 seconds is pretty coarse to predict a spot speed.
If the only tool you have is a hammer, you'd better start looking for a carpentry job.
" At issue was the distance from the stoplight -- site of the first GPS 'ping' that showed Malone stopped -- to the second ping 30 seconds later, when he was going 45 mph." No matter what, a car that goes from 0 to 45 in 30 seconds is crawling. Gimme one, I am that old fart in front of you in the fast lane:P
Radar Guns aren't completely accurate all of the time. But a 40% increase is far beyond what you might expect from an incurrently calibrated radar guns. The only realistic alternative is hitting a car travelling in the other direction but since police are trained to only use a radar gun on a straight road and at a certain angle that might be unlikely too.
So in this case I would side with the police. Unless they're just flat out lying which I cannot discount.
'This case ensures that other law enforcement agencies throughout the state aren't going to have to fight a case like this where GPS is used to cast doubt on radar,' said Sgt. Ken Savano,
Well if the summary is true (and I know it might not be), it actually means the opposite since the GPS data was considered at the trial. That means others may try to present their GPS data in future. It certainly doesn't mean that people can't try that defense. There was no precedent set that the GPS data was less reliable than the radar. It's just that the GPS data could be interpretted to be in agreement with the radar data. Also, this is only applicable to one kind of GPS unit under one very limited set of circumstances.
In other words Sgt. Ken Savano is either misrepresenting the whole situation or is incompetent when it comes to the prosecution of speeding violations. Either way he's coming across as dim witted and it raises serious doubts for me about his ability to perform his duties as a police officer, since he can't seem to understand the law.
These posts express my own personal views, not those of my employer
Since the article didn't give enough information (and manages to misspell one of the street names), I googled around and figured out the path taken (from http://www.pressdemocrat.com/article/20071002/NEWS/710020308?Title=Case-pits-police-radar-against-GPS-in-teen-s-car#): http://maps.google.com/maps/ms?hl=en&gl=us&ie=UTF8&oe=UTF8&msa=0&msid=105238595049957684644.000477c5e46e20fe9dff3&ll=38.2325,-122.591393&spn=0.010956,0.010257&z=16
The first point is when he was stopped at the intersection, the middle is (probably) where the cop got him on radar, and the end is where the GPS clocked him at 45 MPH.
I estimate that's about 2.2k feet from a dead stop in 30 seconds, which puts his average speed at 50. It's pretty much a given he was speeding when the cop radar'd him and he put on the braked.
From TFA, the pings noted were actually 30 seconds apart.
My last GPS reported speeds every second.
So, the question is, what was the ping rate of the GPS on the car? Was the logged value the average of the past 30 seconds of pings, or just the most recent ping?
(Yes, in all likelyhood, it's an average of values, the kid was speeding, and figured that if he didn't go over 75 and trigger the auto-phone-home-warning, his parents wouldn't find out.)
This ruling establishes case law from here forward. Her ruling was in favor of the Police and their technology. Lawyers from here forward will stand a snowballs chance in hell of appealing, even if the GPS data is right and the radar gun is wrong. THAT was the point of this ruling, and unfortunately, it smacks of corruption.
Criminal, you might still stand a chance in proving your innocence these days. Civil? You might as well bend over now. Pisses me off.
Are you serious? The article is treating traffic court to some kind of regular court standards... Traffic court is a fucking kangaroo court with dubious legality and no oversight.
Everything about it stinks to high heaven from the magistrate who is supposed to be unbiased but is really trying to con you to the judge who acts as judge, jury and prosecutor.
The judicial system is only supposed to adjudicate over a matter when one party can show damages caused by another. I'm sure this is not the case for silly traffic tickets.
I wish some lawyer who is familiar with how the real court system works would chime in and list all of the differences here.
I have witnessed many times people making illogical arguments and fining drivers when clearly under any type of innocent until proven guilty system the drivers should have gone free.
Traffic court systems are chaotic, disorderly and inconsistent cesspools of nonsensical arguments and big egos...
There is only one way to describe the whole traffic court system: unconstitutional.
The only reason it remains is because of the sheer massive size of the monstrosity, how much income and how many jobs depend on the entire thing.
Liberty.
No, and allow me to dismiss this as some anti-The Man banter. Radars are standardised, calibrated, designed for the purpose, operated in proper condition by trained operators, etc... The log from someone's GPS is made by the software from some company which won't necessarily disclose how it gathers, processes and stores its data, furthermore those can be imprecise (how many times does your GPS show you as crossing through buildings when you're driving in city centers?), and who's to say that no one tampered with the data (in this case, edit the data in the log to make it seem impossible to have speeded).
So the decision is only common sense. If you really need an analogy, that's as if you provided a court with a written transcript of conversation when they have an audio recording done with their own equipment of the same conversation.
You just got troll'd!
How the court can even consider comparing stationary technology that operates up to a few hundred meters with something that is 20,000 kilometers away traveling at 14,000 km/h is beyond me. GPS accuracy is effected by builings, mountains, etc.
Freedom of speech doesn't come with bandwidth.
A GPS typically calculates velocity from Doppler shift of the D-band signal. This give higher accuracy since the position reading is somewhat unreliable. It also means you can (in principle) get the velocity information virtually instantaneously without having to sample two locations. However, in reality a lot of averaging and filtering is going on, and I think many receivers weighs in both position deltas and Doppler shift in the equations, so the reading is going to have at least some lag.
(Reference)
... operated in proper condition by trained operators, etc...
I suggest that this is not the proper usage for a police force.
So assuming he gunned it as hard as he could and he accelerated and decelerated linearly, I estimate his max speed to be between 68 to 70 mph over a period of 8.83 seconds. That is at the max acceleration he can achieve that would fit the data (60 mph in 7.74 seconds). Any other peak speed would require slower acceleration (its like a parabola). He could have accelerated faster than that, but 7.74 seconds is reasonable for an average car.
Fuck the parents and fuck the kid. A good parent would have told the kid "tough luck, we pay the ticket and you pay us back from your allowance". But noooooooooooo, better to make a fucking mountain out of a grain of sand at taxpayers' expense to prove a point that is questionable to anyone with a basic understanding of calculus and physics.
Please mod the parent up to the moon. I've been reading all the comments on the story, and it baffled me that no one caught this simple fact - GPS logs can be easily tampered with, or even forged. I don't know if the ruling on this case was made with this technical knowledge, but it's nevertheless a good thing a bad precedent wasn't set. Nevermind GPS accuracy, GPS logs just aren't a reliable source of evidence in the first place.
Agreed,
There is no real data integrity with these devices.
I can get the track log of my GPS, manipulate the data and then shove it back in to the device...
Any good lawyer could get this 'evidence' thrown out.
There's been cases here in Australia where the GPS evidence WAS allowed and they got off the infringment, but I can only assume that the prosecuting lawyers were incompetent and did not pursue the possibility of bad data in the GPS.
Also, the Radar is a certified calibrated instrument,and the GPSr is not. Although accurate, there is always a variable amount of uncertainty in every reading (up to 10-15 meters per sample in a moving vehicle) and in a majority of GPSrs this uncertainty is not stored in the logs. Radar wins again on that front.
As for the logs, most GPSrs I use store the last speed value at the log interval, not an averaged speed between then and the last stored sample, so it is safe to assume at X time on the log the car was going Y speed, but for the 10 seconds in between it could have been going anything between 0 and lightspeed. (presuming it is storing every 10 seconds.....)
Burma?
Since he did not take money for this. It sounds like he was trying to prove something. However, even without math AND the fact that the time interval was so long (30 seconds is a long time), it should be obvious that he was clearly speeding. If average is 45 and he started from a stop, then at some point he was going much faster than 45.
OTH, if these units get smart, do 5 (possibly 10) second intervals (still possible to speed a bit and slow down, but not that much), then it would be worthwhile using them to prove that radar is wrong. OTH, I suspect that there will be VERY few times where they differ.
I prefer the "u" in honour as it seems to be missing these days.
No, you both missed the point. The accuracy of the GPS unit wasn't challenged in the court, it said so in the summary. The GPS data was found to support the radar gun evidence. Don't feel bad, apparently Sgt Savano also missed the point. If this is the only precedent, then GPS data is still fair game in a courtroom, and disproving it will have to wait for another day.
And to 4D6963, be careful not to confuse the GPS position data with the map data that it overlays to produce the amusingly inaccurate anomalies you describe. The position data may be far more accurate than the map data.
Rule of Slashdot #0: You and people like you are not representative of the larger population. - A.C.
Actually radar guns often suffer from not being calibrated or operated correctly. Laser speed guns too.
The main problem is that they need a fairly flat and vertical surface to bounce the radar/laser beam off. Cops usually use the car license plate but their aim has to be pretty good.
The radar in speed cameras is even worse, so bad in fact that here in the UK the radar is not used in a prosecution. Instead they paint lines on the road and take two photos a short time apart to use the distance travelled relative to the lines to calculate speed.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
So can video timestamps, and sales records in shops, and tax receipts, and vehicle number plates, and all manner of other things.
If there is *suspicion* that the records have been tampered with, you would be charged with attempting to pervert the course of justice AND your other offences. The fact is though that, 99.99% of the time, people are happy to incriminate themselves, or the courts are willing to believe (on the balance of things) the words of honest people (even if they are before a court - your reputation, manner and appearance mean a lot when it comes to believing what you say - this is why the words of qualified professionals are able to be submitted as evidence). Which is good, or every single bank robber would claim that the CCTV was inaccurate, or the witness didn't really recognise them from the line-up but just guessed.
Law isn't a rigorous scientific discipline except as concerns evidence that may be in doubt. Nobody here questioned that the GPS logs were inaccurate because they were fairly sure (beyond reasonable doubt) that they could be trusted. Otherwise every bloody court case and fine would take decades to resolve.
Timestamps on CCTV submitted from a shop to clear someone's name are the perfect analogy here. The timestamps are believed because the person submitting them *probably* wouldn't have gone to the effort of faking them and, if they did, it would be hoped that this would be known, detected and counteracted. But I can easily set my CCTV system to run an hour late/early and then change it back before the police try to analyse my equipment. That timestamp could easily incriminate / clear a person, but the relevant words here are "beyond reasonable doubt" not "absolutely 100% scientifically impossible".
$ units 'fps' 'mph'
* 0.68181818
/ 1.4666667
adrn@duck:~$ echo '2040 / 30 / 1.46667' |bc
46
Standard web refs give the 0-60 perf of cars, not 0-45,
which are probably not as simple as just taking 0.75 of the 0-60 time.
GPS beat SPECS-speed camera In Court in the Netherlands in 2008.
From: http://www.wegenforum.nl/viewtopic.php?f=49&t=11692
In Holland we have the so called SPECS-speed cameras. These camera's measure the average speed over a traject of a fixed distance.
This article describes a case where the lawyer doubts (after GPS data was presented) if the measurement of the SPECS-speed camera was right. Ultimately, the offender did not get a fine.
Or maybe he learned from his mistake.
"It recorded Malone sitting at a stoplight at Frates Road and 30 seconds later going 45 mph 2,040 feet farther down the road, according to Heppe."
d=rt so we have 2040 = x * 30 so 2040/30 = x x=68!
Yep - GPS proves he was speeding.
that's 68 ft/sec or about 46mph
This article has important details about why the commissioner believes the GPS data supports the ticket.
http://www.pressdemocrat.com/article/20081206/NEWS/812060371/1334/NEWS
Apparently, the GPS logs position, time and speed every 30s. Regardless of how the system calculates speed, whether by averaging between each logged point or using much smaller time intervals, the data shows that the car was stopped at some t = 0 and had moved 2,040 ft after 30s. That results in an average of (2040 ft) / (30 s) = 46.36 mph.
Assuming a linear acceleration profile, he would have had to reach a speed of 92.72 mpg to run the 2040 ft in 30 s, but that's an unfair assumption. He was driving a 200 Toyota Celica GTS, which accelerates from 0-60 mph in 6.6s, thus at a maximum he can increase his velocity by 9.1 mph each second (assuming constant acceleration). Thus, the absolute minimal velocity the driver must have reached is 51 mpg, reaching this velocity in 5.6s and maintaining it for the remainder of the path to the next logged point.
The article does not specify where exactly was the police officer read the car's speed, which is crucial to understand if the 62 mpg reading is possible, but the conclusion is that the GPS data by itself does prove that the driver must have been above 45 mpg but does not guarantee that a speed of 62 mph must have been reached.
Or maybe we caught a glimpse of the real Barack Obama.
That's not implied at all except by the personal statements of the Sgt who has no say in the matter.
The GPS data *was* right and it showed one thing conclusively, the teenager had been driving in excess of 45mph during some fraction of the last 30 seconds. The GPS is not capable of making statements about your current speed, it can only state your average speed since the last data point.
To go from a stop to averaging 45mph would require a top speed in excess of 45mph. All you can do is bracket his speed with the GPS not specify it, there are too many unknowns.
1) How long was he stopped at the light from the last ping to when it turned green
2) What was his rate of acceleration
3) After reaching top speed was his speed constant
If he sat at the red light an additional 8 seconds and then instantaneously began moving at 62mph he'd average 45mph over the previous 30 seconds. (62mph for 22seconds is ~= 45mph for 30 seconds).
If he took 12 seconds to accelerate to 62 mph he'd average 45mph over 30 seconds.
GPS data will be perfectly permissible in court, your civil rights haven't been trampled.
I'm going off-tangent here, but to me, the whole thing is just another reminder, that our driving — a very important part of life for many — is often not judged by judges. You don't even need to read the article — the /. write-up says: "Last week, Commissioner [emphasis mine -mi] Carla Bonilla ruled [...]"
At some point decades ago, when no one was paying attention, driving on a public road was deemed to be privilege, that the state may grant or take away, rather than a right, to limit which the state has to prove its case to a judge (forget jury).
In many locales, traffic cases are handled by the Judiciary anyway — because the Executive does not want to bother with its own system for hearings and appeals. But in some places — like NYC and, evidently, in Sonoma County, the cases are decided by the Executive branch itself — by people reporting to the same bosses (such as mayors) as the ticket-issuing cops...
And this is just a tip of the legal iceberg, that ACLU and other purported guardians of liberties ignore... In addition to driving, a mind-numbing number of activities require a license. In July two people were arrested on Times Square for "performing in costumes without a license" — they weren't charged with anything else...
This licensing is a terrific way for the Executive to punish anyone they don't like without the trouble of convicting them of any wrongdoing — instead of going to the Judiciary to prove its case, an Executive Branch bureaucrat can simply withdraw the license, or, even simpler — not renew it. At best, you may be able to appeal the action in front of the Judiciary yourself and — presumption of innocence be damned — prove, that the Government erred.
From driving, to selling liquor, to broadcasting — we have to rely on the government's benevolence in order to Pursue our Happiness... How did we get this far along this terrible road? How do we stop marching forward on it?
A government big enough to give you everything you want is a government big enough to take from you everything you have.
In Soviet Washington the swamp drains you.
I was once ticketed for doing 45 in a 30 in a woefully underpowered car. The ticket the cop wrote (which I did not see in full until my day in court) claimed I was 30-40 feet from a stoplight where not only did I stop, but I made a right-hand turn. I had two guys in my car with me, which didn't help the car accelerating on flat ground (this was a very flat area of a very flat state). So basically for the ticket to be correct, this car which made around 70hp on a good day needed to be accelerating at Porsche speed while turning.
The ticket that the officer gave me that day (which was missing some of the critical information such as the location where he claimed I was) had a court date on it, so I went to court armed with information on how I could not possibly have been going as fast as claimed.
Instead I was greeted by a DA for that county. I had the option to come back later to be heard by the judge, but the county was quite a ways away from home and I didn't really want to go back. The DA offered me a "plea bargain" since I had no tickets on my record prior. They said I could enter a plea of "guilty not accepted", under which they would accept a lesser fine from me than the original ticket (the DA essentially changed the reported speed from 45 to 38, still in a 30), and as long as I was not pulled over in their county again for the next 12 months the ticket would not be reported to my insurance company (I was a young man at the time so that part was important to me).
I accepted that deal, wrote them a check that day, and I haven't returned to that county since.
Damn_registrars has no butt-hole. Damn_registrars has no use for a butt-hole.
Does the radar reading have a time stamp? If not, then the case should have gone to the GPS since the accuracy of both were brought into question. That being said, what kind of crappy GPS only samples every 30 seconds? That's useless.
You're both wrong.
They heard the case on the merits of both technologies, and did NOT rule against GPS in favor of radar. They merely concluded that the GPS supported the officers case, not the kid.
Go to court, plead not guilty, cop shows up states you are, ask to see the witness. Cop says he's the witness, nope he's a 3rd party to the witness. The actual witness is that radar detector he claims he was using. When was it purchased, was it dash mounted, has it ever been dropped if it's hand held, how is it handled (I've seen cops toss them into the passenger seat and fly after speeders), and most importantly. Produce the calibration certification and it's calibration requirements. I'm sure 90% of police districts are too cheap to calibrate these devices on time if at all.
This shit flys for traffic cameras as well. You're allowed by law to face your accuser, in both cases the cop is not the accuser, it's the devices the use to contend your're speeding.
Just dont be fighting it if you know you were actually speeding. Also I wonder how much those parents spent to fight this. Surely it was more than 190 dollars.
All of the GPS units I own and have owned show the speed averaged over the last second, even if they only RECORD it every 5, 10, or 15 seconds. So a recording of 0 followed by a 45 does not mean I averaged 45 over 30 seconds (to use the example given in the story), but that I was doing 45 during the second that the position is recorded.
Either the software in this GPS tracker is wildly non-standard, or someone missed presenting the correct information to the court.
The radar in speed cameras is even worse, so bad in fact that here in the UK the radar is not used in a prosecution. Instead they paint lines on the road and take two photos a short time apart to use the distance travelled relative to the lines to calculate speed.
Not strictly true. There are at least a couple of cases of people contesting a speeding ticket and discovering that the prosecution had gone ahead without actually checking the photos - which of course exonerated them.
The kids dad was the one who fought this the whole time.
The dad got the GPS because of prior infractions by his son.
The kid got 2 other motor-vehicle infractions while this case was proceeding.
Halfway through the case, the dad changed their defense from "The radar gun was wrong", to "It was an illegal speed trap."
They knew they were going to lose the whole time, they just hoped the county wouldn't put out the money.
Example:
They waited until the county had paid the expenses for an expert to come fly cross country and testify. Right before he was to testify, the kids lawyer got a continuation so the expert had to go home and get paid again to come out later.
The kids dad was the one who fought this the whole time.
The dad got the GPS because of prior infractions by his son.
The kid got 2 other motor-vehicle infractions while this case was proceeding.
Halfway through the case, the dad changed their defense from "The radar gun was wrong", to "It was an illegal speed trap."
They knew they were going to lose the whole time, they just hoped the county wouldn't put out the money.
Example:
They waited until the county had paid the expenses for an expert to come fly cross country and testify. Right before he was to testify, the kids lawyer got a continuation so the expert had to go home and get paid again to come out later.
Another explanation is that the cop was fishing. When the plates were clean and the kid did not turn out to be drunk or on drugs he made up a number and wrote a speeding ticket. Happens all the time.
I think theres a massive cover-up about the accuracy of radar guns. I think the cops and courts all know it but its a massive income generator so they wont do anything about it.
I got stopped by a cop with radar claiming he detected me doing 85 in a 65mph limit. He even showed me 85 on the radar. It was rush hour and the freeway was bumper to bumper stop-go traffic and there was no way I ever got over about 45. I was also surrounded with other cars so I have no idea how he could single me out with a radar. My wife was in the car too and told him I couldn't have been speeding but he didnt believe her either. I went to court to fight it and they made a deal before my case got heard to reduce the speed down to 78 but I still had to pay a fine. It seems to me they wouldnt have done a deal if they thought the radar was truly accurate.
It seems everyone fights based on the accuracy of the radar, but I haven't ever herad of anyone the lack of evidence that the cop was actually pointing the radar at your car and not someone elses?
Nope, as has been noted above, the GPS data proves beyond a shadow of a doubt that he was speeding. There's two witnesses, radar AND GPS. If the car accelerated 0-60, instantly, his average speed between the two GPS readings is still over the limit -- not by much, but speeding is speeding, and if you're going to get pedantic enough to take it to court like that, the court can be pedantic back at you. The longer it takes him to accelerate, the longer he had to brake after seeing the cop, the higher his maximum speed must have been.
I think this was an excellent result, and it could only have been better if the family had gotten dinged for the extra costs they incurred for the prosecution by gaming court dates.
There's a case to be made that the entire speeding prosecution system in the US has gone way, way overboard, and that it's morally justified to fight speeding tickets just to make it more difficult on the people who perpetrate this bullshit.
I bet the morons who spent $15.000 on an expert witness and countless hours of the courts time debating mathematical theories never thought to take the car and GPS for a test drive and find the truth.
from the wording of the story there are only two gps data samples being taken into account, two pings that were sent to the parents.
the first shows the car at 0, stopped. and the second, 30 seconds later going 45
that's simply not enough data to know how fast the kid was going.
we don't know if he reached 45 within those 30 seconds and then held there, of if he just happened to be going 45 during that ping on his way to 60 or some higher speed.
it does seem that he at least held 45 for a few moments, after all it's a bit unlikely that the 2nd ping would happen to occur at the exact instant that he was at the speed limit yet accelerating. Still there's no conclusive proof one way or the other with only two pings.
maybe the defense brought in more gps data recorded by the in-car unit and not sent out to his parents, I don't know.
can you plot two points on a graph and tell me weather the function is linear or quadratic?
Even worse is when my local council discovered that the road markings were themselves incorrect and so all the fines and points collected over the last three years were invalid. Rather than sorting it out though they just decided to wait for drivers to contact them and deal with each one on a case-by-case basis.
Imagine loosing your license and paying all those fines only to find out it was all a mistake. I think there are civil suits going through at the moment, but the local rag is a bit thin on detail.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
It still comes down to whether the radar gun was wrong or the GPS was wrong. Since they didn't agree on the speed, at least one of them must be wrong since it is not possible to actually be going two different speeds at the same time in one vehicle. Or it could have been operator error (radar gun actually picked up reflection from another vehicle the cop didn't notice ... this kind of error actually happens a lot). It sure sounds fishy that they are saying that they are not challenging the accuracy of the GPS, yet they are challenging the numbers from it. It sure sounds like they are challenging the accuracy of the GPS (and maybe it really is inaccurate).
As for the court games being played ... typical lawyer shenanigans. They all do it to try to get the upper hand. It means nothing about the basis of the case.
now we need to go OSS in diesel cars
the other thing you have to consider, when you put the math aside; would a kid really be stupid enough to speed if he knew his parents had installed a gps speed monitoring unit in his car?
maybe..
These exist to prove that you are speeding. If you have a habit of driving too fast (10mph over the limit on highway and so on), 1/30 Hz is more than enough. It doesn't catch every time you go 3 mph too fast when you are trying to pass someone but that's not the point.
That data's impossible to fake.
Honestly, is the Court going to believe the measurement of a piece of equipment on the defendant's car? The defense might as well include a photo of the speedometer at 35 MPH proving innocence! I have all kinds of data showing that I wasn't speeding, believe me.
So what? A microscope, a scale, a caliper can be a certified calibrated instrument. If it is used incorrectly or if the operator doesn't know (or care) what factors can interfere or give false readings the results are no more reliable than an eyeball estimate. Actually, it would be worse because it could give incorrect results undeserved validation.
The only thing this ruling establishes is that if you're going to use your GPS data as evidence, make sure it actually proves you were not speeding, instead of agreeing with the radar.
This particular GPS might have been engineering to prevent log tampering, given its intended application.
"Might have been" tends to trigger the same kind of innumeracy as the mass of the earth's atmosphere (5 x 10^18 kg). We get a bit stupid confronting all those zeros.
Are we talking about an arithmetic "might have been" which can be expressed in two digits (0-1 in 1% increments)? Or are we talking "might have been" which can be expressed in two digits (10^-99 to 10^-epsilon)? Are we talking about less difficult than rigging an election machine, or more difficult than fleecing an ATM?
We'd all waste a lot less breath if people throwing the word "might" around would kindly confine it to a single order of magnitude: 10^-(x+0.5) .. 10^-(x-0.5) for some stated value of x >= 0.5.
This concerns the value of "might" on the family's own steam.
It's a whole different matter to position might after the family engages a criminal mastermind to perform their bidding. Ordinarily, in law, the rule of thumb is "No capes!" when deciding what might have happened. They will quickly teleport you to a criminal docket if this presumption fails to hold.
When I see (presumably) US people keeping getting lsot with feet per second and mph, I jsut say : for pity's sake use USI.
it is still up to the police department to PROVE that that particular radar gun was properly calibrated at the time of the ticket, and that the officer was properly trained in it's use, and up to the manufacturer to prove that the device has no flaws in how it calculates speed. this is true for every single ticket issued.
before anyone complains at how much this would cost or how much of the courts time it would waste, it is far more important that the state not be able to take away your property or liberty (fine or jail) without being sure and being able to show it really is sure that you deserve it.
Ya know: "If they can get you asking the wrong questions..."
Set your phasers on "funky"!
Apologies if this has been mentioned (I did look through the comments)
But can anyone explain how it was really 30 seconds? The GPS ping isn't a stop watch and has no clue what the vehicle is doing. it just does a check in every 30 seconds. So if the 1st ping hit say 5 seconds before he left then he was moving for only 25 seconds instead of 30 thereby increasing his rate of travel. The odds are 1 in 30 that he left within 1 second of the first ping.
In Spain the last year a driver was fined to lead to 750 km/h. They didn't not cancel the punish because it was accept that the radars fail. The new, in spanish.. http://www.lavozdegalicia.es/galicia/2008/06/19/0003_6917433.htm
1010011010
Using your same argument, the radar data is only as good as the cop writing the ticket.
However, we know that cops are the most moral and infallible human beings who would never inflate a radar reading to increase revenue and/or hit their quota. /sarcasm
The problem with this is that the maker of the radar gun is no more likely to release the source code for the radar gun then the gps manufacturer is to release their source code.
So, the Military has multi-million dollar radar systems, operated by a team of specialists, that think a 30,000 pound airplane is a bumble bee. But a hand-held unit costing a few grand & operated by Officer Bubba is infallible?
First: I'm a liberal. In west Sonoma County, a VERY liberal county. I feel that there is a lot wrong with the way our government and our country is running these days. I'm a cynical guy.
I have had the... yes, pleasure of arguing my case before Commissioner Bonilla. I was ticketed for the first time in 19 years for going over the speed limit on an emergency call to take a stranded friend to an emergency surgery. Please understand that vast tracts of this part of this county are extremely rural, and waiting for an ambulance for 20 minutes or more is not an option at times. I researched the case, and decided without doubt that it was an illegal speed trap and was prepared to fight it.
I was the last case called and had the opportunity to observe two hours of Carla Bonillas' judgement.
I left that courtroom heartened by the fairness, consideration and thoughtfulness the woman displayed in working through legal requirements placed upon her, yet managing to help a large number of people who were cited for perversions of logic and law. She demonstrated an awareness and a humanity about her decisions that really impressed me. I mentioned to several friends that I was relieved and uplifted to see that kind of behavior on the bench.
I'm quite certain that in this case she would have done as I witnessed in other cases and acknowledged the limitations of her knowledge on a given subject, asked for input, and ruled in a way that would provide the most reasonable solution.
Her reasoning is sound, and she explains it to the court.
Disclaimers: I don't know Commissioner Bonilla, I don't have association or knowledge of any of the parties, and I'm not associated with law enforcement or the County of Sonoma other than living here. Also know that she is an appointee, and does not run for office. She states this at the beginning of each court session.
FYI, She ruled in my favor after hearing my arguments, followed as the law stipulated and dismissed the case.
My opinion of her methods had already been formed by that point, and encouraged me to get up there and argue, comfortable with the idea that this judge would be fair.
This case started right after CA bought Lidar guns to use as speed enforcement in the state. Lidar, unlike radar, does not measure speed but distance. It takes multiple distance readings, does some simple math, and then finds the average speed from those readings.
So right when our state upgrades to technology that is near identical to GPS the courts throw out GPS as an accurate source of data because GPS does not measure speed but a mean of multiple distance readings.
If I get a speeding ticket via lidar in the future I'm going to have to pull up this case and turn the tables around because this is ridiculous and ironic, if anything.
GPS is much more accurate. All of the high accuracy (read expensive) parts are on a relatively small number of military satellites. The receiver doesn't need to be all that great, and can self calibrate off the satellites. Hand held radar and laser units must be self contained, so the sensitive bits are much cheaper commodity parts. Calibration is also an issue. They are also bouncing their signal off of car bodies that aren't exactly even, increasing difficulty getting a reading. Hence stories about someone clocking a judge at 45mph...sitting on the bench.
except that cops LIE all the time, point the radar at the sky/big trucks to give false readings, try to grab out of towners based on license plates and do this ALL THE TIME. the two tickets i got - i fought them all in court and won both. a 100% success rate. this would not be possible if i was actually speeding. but it is very possible based on the fact that cops LIE and you can make em stumble in cross examination. i'd believe a civilian GPS over a lying cop any day of the week.
I think that the mathematics tell us that it's at least more likely that he was going over the speed limit than not. That aside, it raises some serious issues that need to be addressed in the USA.
First off, I'm not sure about other states, but in Indiana, the prosecution does not have to "prove beyond a reasonable doubt" that you exceeded the speed limit. They only have to prove 51%. Why? Because in Indiana, it's considered a "civil" case. WTF??? So now, because of a semantic game, I can be convicted of breaking the law on a lower standard. If it's your word against the officer, you lose. Period. Case closed. I'm sorry, but it was little things like this that birthed the concept of "innocent until proven guilty". You can't dismiss it with a play on words. This needs to be addressed at least by Indiana lawmakers. But it won't be. It's "too minor". What's next -- shoplifting? And then armed robbery??? Let's face it -- while most cops out there are gold, there are cops that lie.
Second, most speed limits are set extremely badly. In my town, we have a road where the speed limit is thirty miles per hour. No one does it unless the police are clocking. If you go thirty, I can practically guarantee you will be tailgated, passed, and/or get the bird. Probably with a lot of profanities involved. It seems like every time I turn around, the government is coming up with more excuses to come up with 25MPH speed limits (at least in my town). Oh, and then there's the place where there are two speed limit signs less than 100 feet apart. The first one you see reads 50, the next one 20. The police clock there all the time. You can't tell me that's not a racket.
Third, cops target red cars and sports cars. WHY on earth would you do that? If any car is safe to speed in, wouldn't it be a car that can maneuver without worrying about turning it over??? (*cough*SUV*cough*) And before anyone says they don't target sports cars, I've actually heard retired police officers admit that they do. On multiple occasions. Why don't you pull over that guy in a minivan that just passed me like I'm standing still? Does the law somehow apply to him less?
Sorry for the long rant, but this sort of touched a nerve. I've had to PROVE (beyond a reasonable doubt, by the way) that I wasn't speeding on four separate occasions now. I shouldn't have to prove my innocence. I won all four, by the way.
What it boils down to is traffic law is hopelessly screwed up.
And to 4D6963, be careful not to confuse the GPS position data with the map data that it overlays to produce the amusingly inaccurate anomalies you describe. The position data may be far more accurate than the map data.
No, bullshit. Try driving with a GPS in a street entirely surrounded by high buildings, you might find yourself with an unusually high imprecision, mostly on the axis perpendicular to the direction of the street.
You just got troll'd!
that think a 30,000 pound airplane is a bumble bee.
lol, what?? Are these radars hemp-powered by any chance?
You just got troll'd!
Did you not notice that I used the word "may"? Do you know what that means? Do you think that maybe sometimes (but only sometimes) it's not the GPS data that's at fault?
Rule of Slashdot #0: You and people like you are not representative of the larger population. - A.C.
As others have mentioned here, the accuracy of the GPS isn't even a factor in this case. Even if the GPS data is 100% accurate, it is still consistent with the data collected from the radar gun thanks to the painfully long sampling interval.
If the device reported a 45mph average over a 15 second intervals (as opposed to 30), one could possibly make the argument that the officer's claim is not consistent with the capabilities of the car (or any remotely sane driving practice for that matter), the scenario described by the attorney is completely plausible.
I'm very glad the kid got to defend himself in court. However, in the end, the math didn't bear him out.
-- If you try to fail and succeed, which have you done? - Uli's moose
Who cares, that's not the point of what I was talking about. I said that GPS localisation imprecision can show you way off track, which is a correct claim. You say that other things can show you off track, which is irrelevant, since it doesn't affect the correctness of my first claim.
So, I was talking about something, you replied and talked about something else no one gives a crap about, so I replied by explaining how what you brought up doesn't invalidate my point. Or if you prefer, you're not wrong, but off topic.
You just got troll'd!
"Radar signature approximately the size of a bumblebee, thereby avoiding detection by the most sophisticated enemy air defense systems"
http://www.f22-raptor.com/technology/stealth.html
Wow, holy shit you're one dumb mother fucker!
So, the Military has multi-million dollar radar systems, operated by a team of specialists, that think a 30,000 pound airplane is a bumble bee.
Haha dumbass! Radars don't think the airplane is a bumble bee, the airplane is designed to have the radar cross section the size of a bumble bee, as to avoid detection entirely. The radars don't think it's a bumble bee, they just can't detect it, because the plane was specially designed to avoid their detection!
Wow, your moronity is mind blowing. That's really something exceptional you have there. I mean it, sounds like the kind of stupidity that is so intense that it actually becomes your best asset, like, people could pay to hear dumb shit like that!!
You just got troll'd!
Yeah, but form the point of view of justice, it doesn't even matter, as I pointed out there are many reasons why they shouldn't allow that kind of thing.
You just got troll'd!
That section of Lakeville Hwy is pretty busy during the daytime, I dont know if he was first in the front of the line at the light but if he was not then it is likely he was flowing with the traffic off the line.
To give you an idea of the attitude of local LEOs there in Petaluma in that area, I was coming out of a coworker's house at about 1:30 AM on a week night and entered my parked and dew covered car, a cop who had been sitting down the block with his lights off (I saw him there as I was walking to my car) came screaming down the street, did a U turn, lit up his floodlight, came over and started grilling me about where I was, what I was doing in that neighborhood, etc. All unlawful questions as he was not investing a crime, just pure harassment of citizens - he did not ask for my id or papers because he knew I hadn't done anything, not even pulled out of the parking space. BTW, white, middle aged, no tattoos, Honda sedan.
GPS is much more accurate.
Wrong.
The GPS signals accessible by civilians are significantly downgraded from what the military uses for their operations.
Radars are standardised, calibrated, designed for the purpose, operated in proper condition by trained operators, etc...
Yes much like voting machines....
Am I the only one bewildered by the fact that the cop was writing a ticket every 4 minutes!!!!!!
Maybe I don't have enough data, but the ticket was for doing 62 MPH at a certain moment, as gathered by radar? Instantaneous speed, no averaging.
GPS says he was doing 45 MPH at about that moment, no averaging, instantaneous.
One has to be wrong. The most obvious, different moments.
I would like to be able to trust a unit installed in my son's car to report accurately if I'm going to pay for that service, and accelerating faster than the speeed limit is wreckless on behalf of the son, as he should have no idea when data is gathered and transmitted.
Personally, I believe the GPS, if the manufacturer is in court and proves their technology accurate. Afterall, aren't they thinking of going to robotic cars with GPS based spped control?
Larry
According to Google maps the distance is 1712 ft. Not that I trust that distance.
So d=rt or r = d/t gives us (1712/5280)/((30/3/600) or an average speed of 38 mph.
That still doesn't tell us whether he speed up to 69 mph and then decelerated to 45 mph, or what. We still lack one vital piece of data, how fast can he accelerate to 60? So let's take one of the internet figures 7.2 sec, and a 1/4 mile in 15.4 sec, reaching 90 mph, and a braking distance of 120. So He could have accelerated to 90 mph and come to a complete stop in a distance of 1440 ft. So, it's definitely plausible he was speeding.
So let's assume he sped up to 60 as fast as he could. That leaves us with a guess of the distance covered, we know it takes another 8.3 seconds to reach 90mph. So let's be generous and say it was 617 ft ((7.2/15.4)*1320).
That means he would then have to travel another 1712-617 = 1095 ft in 22.8 seconds and be doing 45 at the end of that.
Now his average speed up to this point would be (617/5280)/(7.2/3600) = 58 mph
So (58*7.2 + 22.8r)/30 = 38 or r = 31 mph.
So our little speeder had to speed up to 62 and then immediately brake to below 30, stay there for a while, and then speed up again to 45. I will leave the actual algebraic equations and distances as a problem for someone else. Well if, this is true someone needs to take this boy off the roads. But Occam's razor states that, in this case, the likely answer is he wasn't speeding. I find the court's finding implausible at best.
Lastly, this is all speculation as we don't know if it was precisely 30 seconds later, or how long it was after that the car was shot with radar, or really any details in sufficient quantity to follow the Judge's reasoning.
arithmetic, actually.