AGPS - protocol specs?

[Bartlomiej Zdanowski AutoGuard Ltd.]

Al Johnson napisał(a):
> On Friday 09 March 2007 08:58, Bartlomiej Zdanowski AutoGuard Ltd. wrote:
>   
>> You cannot depend on GPS reading to count quite accurate velocity,
>> acceleration and accurate position. Sorry.
>>     
>
> Conventionally this is true, but there are other ways. IIRC RaceLogic use the 
> doppler shift of the GPS signal for speed and acceleration calculations. 
> These can also be used to improve the accuracy of the location. I think they 
> claim it's good enough to compare the line taken by the driver on successive 
> laps of the race circuit.
>   
Yes, my GPS-wise colleagues said that measuring difference between two 
sequential readings it can be possible to compute acceleration because 
reading error is quite same in both readings. So while global position 
is not accurate, difference is accurate. Another problem is reading 
delay so you have not current data (velocity) but data delayed with 
reading period's time. It's not a problem since human don't travel fast 
on foot. It can be while trying to compute acceleration of a vehicle - 
it changes very fast.

Regards
-- 
*Bartlomiej Zdanowski*
Programmer
Product Research Department
AutoGuard & Insurance Ltd.

Omulewska 27 street
04-128 Warsaw
Poland
phone +48 22 611 69 23
www.autoguard.pl <http://www.autoguard.pl>
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