Black Boxes for ACT Police Cars!

Thumper, the Yanks turned it off several years ago.

About the same time that GPS became a little more mainstream and started being used for such things as building construction etc (aka where errors involved lengthy court battles).

There are several reasons why they turned it off:

1. GPS devices were smarter, and polled repetitively to find the incorrect information so the device could automatically rule it out.

2. A zealot with a rocket launcher firing his rocket at a building will still probably hit it, regardless of what the GPS anomoly says.

I happen to have been doing some work in this general area lately (vehicle location services), so let me address a few things:

– speed from a GPS device isn’t an average, it’s an instantaneous measure calculated from the satellite time offsets in the same way that position and altitude are calculated. (Think Doppler shift, although it’s not that exactly). It’s likely to be more accurate than a speedo, depending on the reception conditions.

– the inbuilt inaccuracy (“Selective Availability”) is no longer activated in the general case. The US still maintains the capability to turn SA on within particular geographical areas. Civilian differential GPS can get down to around 20cm accuracy.

Interesting the minister seems to have been blindsided by this too.

keelty is kicking a lot of cans in the ACT today.

GPS is taking, at best, averages.

I think for this to work you’d need full input from all the car controls.

for example you’d want to know exactly how fast the car was going at a particular moment AND was it the brake or the accelerator being applied.

Your speeed is just other data that a GPS produces automatically. No connection to the speedo required.

We’ve already got GPS in plenty of vehicles (those magic smart buses, for example) and it’s surely not all that hard to continuously record GPS coordinates along with additional data on speed coming from the speedo.

That’s all Keelty seems to be talking about.

So the commissioner is blowing smoke?

Intersting… completely untrue but interesting.
On board computers are a good 5-10 years off let alone the “black boxes” to go with them.

As for being useful in pursuits, it still wouldn’t stop poindexters swearing that the police car and the pursued car are closer and faster than they really were. http://en.wikipedia.org/wiki/Clea_Rose

“Such a system would have been extremely useful in investigations over Clea Rose’s death.”

…..unless it was malfunctioning or unservicable.