[OSM-talk] Choice of GPS for bicycle use in London

[Martyn Welch]

Hi all,

On Monday 22 May 2006 11:40, Richard Fairhurst wrote:
> If you drive along the same streets as part of a "through journey" -  
> in other words, in one side, across the city centre, and out again -  
> it seems to perform much better. We got a fairly decent track of the  
> A44 through Worcester yesterday, even though cycling the same route a  
> few weeks ago had produced less than brilliant results.

If I remember correctly, GPS satelites are not geo-stationary, so the exact 
number of visible satelites are likely to vary a little over time. I guess 
this may have a strong effect on accuracy in highly built up areas and would 
explain differing results at different times.

Martyn

P.s. I've only every used the GPS receiver I have now, so I guess I can't say 
much in terms of how it performs compared to others, though I have found the 
Bluetooth BT-77 unit I use (with logging software on my Symbian-based phone) 
to be quite reliable. Well, the GPS unit anyway. - MW

-- 

Martyn Welch (welchm at comp.lancs.ac.uk)

PGP Key : http://ubicomp.lancs.ac.uk/~martyn/pgpkey/