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Al Johnson napisał(a):
<blockquote cite="mid200703090944.27991.openmoko@mazikeen.demon.co.uk"
type="cite">
<pre wrap="">On Friday 09 March 2007 08:58, Bartlomiej Zdanowski AutoGuard Ltd. wrote:
</pre>
<blockquote type="cite">
<pre wrap="">You cannot depend on GPS reading to count quite accurate velocity,
acceleration and accurate position. Sorry.
</pre>
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<pre wrap=""><!---->
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.
</pre>
</blockquote>
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.<br>
<br>
Regards<br>
<div class="moz-signature">-- <br>
<b>Bartlomiej Zdanowski</b><br>
Programmer<br>
Product Research Department<br>
AutoGuard & Insurance Ltd.<br>
<br>
<small>
Omulewska 27 street<br>
04-128 Warsaw<br>
Poland<br>
phone +48 22 611 69 23<br>
<a href="http://www.autoguard.pl" style="color: rgb(68, 68, 68);">www.autoguard.pl</a><br>
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