10 hz GPS with bluetooth

[andiih]

Hi,

I'm trying to write some software for racecar performance monitoring, and am after a 10hz (i.e. 10 fixes per second) GPS unit - preferrably bluetooth.

The closest I have come are this http://www.gpsw.co.uk/details/prod2800.html and http://www.race-technology.com/content.php?pcat=4&cat=724 . These are 5hz and wired. Can anybody recommend anything else I can go for ? I'm going to hook it up to a PDA (iPaq) so I *can* use serial if I need to, but I would like to mount the iPaq in the centre of my steering wheel, so the less wires the better.

Thanks in advance,

Andrew

[philpugh]

Interesting question!

Don't know if such a product exists but on another page of a site you referenced is this http://www.race-technology.com/speedbox_4_879.html which can do 10Hz or 20Hz - but costs a bit more.

Unless you absolutely need 10Hz (which is about 6.6 metres @ 240Kmph / 150mph) I would have thought the 5Hz GARMIN represented pretty decent value for money. You would have to get DGPS to get better positional accuracy as the HDOP is going to be in the same order of magnitude as the distances you are trying to measure (presumably). Even then there would still be significant positonal 'error'. If you are looking at speed /acceleration measurements then the same people (race-technology.com) do an inertial platform and 100Hz measurements!
_________________
Phil

[andiih]

Thanks phil,

What I am trying to do is develop some software which I can use when racing to measure lap times and split times and speed traps. The software reports (using a headset) whether each lap and or sector is better than the last, and better than the best. The idea being to give live feedback on whether trying a particular line or gear is better or worse than the alternatives.

I've got the software working with a 1Hz unit for testing (my tom-tom) but with speeds of up to about 120MPH, average lap speeds of around 70MPH, and a necessity to get an accuracy of about 1/10th of a second, I figure the better the resolution, the more likely I am to actually drive faster!

Your calculation of 6.6 meters is interesting...not sure how you get to that. Given the figures above, how accurate (in seconds) would a 5Hz or 10Hz unit be ? Is it as simple as 70MPH=31.3 meters per second - 6.6/31.3=0.21 = 2 10th's @ 10hz ? Twice as bad at 5Hz ?

I get the feeling I should move this out of the beginners Lounge !

[andiih]

duplicate post deleted.

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