[Openstreetmap] How to do gps data logging?

[Richard Fairhurst]

On 15 Jan 2005, at 11:12, Zebedee Mason wrote:

> Am looking at buying a GPS with barometric altimeter for putting on 
> the handlebars of my bicycle to record my rides and subsequently 
> calculate the gradients. Say a maximum speed of 50km/h = 14 m/s and a 
> resolution of 10m, then I want to be sampling about once a second. 
> Over an 8 hour bike ride that comes to about 30,000 sample points.
>
> If I read things correctly then an eTrex Vista is supposed to do about 
> 10,000 sample points per tracklog but comes with quite a hefty price 
> tag (in the UK). Anything lower down the range will have me stopping 
> periodically to save the tracklog into internal memory and start a new 
> one, with which I'm sure I would get quickly bored. Riding over the 
> same stretch multiple times with a lower sampling rate doesn't sound 
> like much fun either.

The eTrex is quite clever with its sampling. Rather than recording a 
point every n seconds, it records more frequently when you're going 
round curves, less frequently when you're on the straight.

I have the basic eTrex (around 1500 trackpoints) and find that it can 
cope with a typical day's driving. In fact, I recently took the 
Caledonian Sleeper train from London Euston to Glasgow Central, placed 
the eTrex in the window, and went to sleep. I woke up eight hours later 
to find that the eTrex's memory was 96% full and had recorded the whole 
West Coast Main Line perfectly. :-)

For a cheap solution, I'd consider the Garmin Geko 201. It has a 10,000 
point tracklog and seems to be largely identical to the eTrex.

Disclaimer: I've never taken much notice of gradients, so don't know 
what the accuracy is like on this.

Richard
www.geowiki.com / www.systemeD.net