phred

the issue of whether GPS is accurate (and admissible as evidence) is going to be determined as part of the Scott Peterson trial, so hold off on buying NAV units for a while ....<ul><li><a href="http://www.foxnews.com/story/0,2933,111054,00.html">Bad boys, bad boys</a></li></ul>

HPH

...the side from which it comes rather than on the truth. For example:

' "The GPS technology has not been generally accepted by the scientific community," Geragos said in court papers filed in October. '

This is a false statement. The scientific community was one of the first non-military users of GPS. Seismologists began using it (with Trimble equipment) long before it was available to consumers generally (back in the early '80s), and using it they've shown how Mt. Everest is growing by a several mm per year (because India is slowly crashing into China, tectonically speaking). That's millimeters. Such devices aren't what's in a car, or what the police put on the defendant's car, but it's still GPS. Other scientific uses of GPS abound.

Whether or not the truth will come out in this trial is, of course, irrelevant to the whole thing. Like the OJ Simpson trial and so many others, the proceedings will be dominated by which side can sway the jury, not by the truth. HPH

LMGotts

These tactics don't add much in the way of public support of "innocent until proven guilty", IMO.

<i>"The GPS technology has not been generally accepted by the scientific community," Geragos said in court papers filed in October. "GPS has inherent inaccuracies."</i>

phred

lawyers have to argue with whatever they have, whatever little they have

dougaross

He's right GPS does have inherent inaccuracies- about 3 meters

Capt William

THe problem with our court system when it comes to issues of science and technology is that people who are completely unqualified are required to make decisions about things they don't understand. A judge is going to have to rule on the reliability and accuracy of the GPS data but that judge has neither the time nor is he likely to have the knowledge to understand the technology he is ruling about.

If the data is ruled admisable then the jury, who were almost certainly not picked because of the scientific or technological backgrounds, is goining to have to consider how much weight to put on the GPS data. The validity of the "expert witnesses" testimony can only be judged by the jury based on how knowlegable the "expert witness" seemed since the jury members aren't likely to know what data makes sense and what doesn't.

We all know that GPS can stop working in a car due to trees or tall buildings stopping the signal. Selective availability has been turned off for several years now so the accuracy of most consumer GPS recievers should be within a few 10s of meters most of the time and within a few meter lots of times. It is also possible that you can occasionally get 100 meter errors but that would quickly show up as an impossible reading when compared to a road map. For example it might show Peterson's car in a lake or driving at 60 mph in a field next to an interstate. Large errors when the car is parked would show the car slowly moving in a random fashion but you could calculate the actual position by averaging the positions over time. It is propably nearly as unlikely, that GPS would show the car simply driving to a location that is never went to, as it is that two people have identical finger prints.