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

[Christian van den Bosch]

Emil Vaughan wrote:
> Would a "usb mouse" type gps receiver
> connected to my zaurus be a more accurate than a geko? And would it
> work ok under linux?

I haven't tested it yet, but I believe that a Sirf Star III should be 
/much/ more accurate than a Garmin log (because it won't lie, I mean 
extrapolate), and significantly better than the Garmin's NMEA output 
(because of its better sensitivity).

The sat nav systems you have seen may use some more "intelligent" 
extrapolation that constrains it to routes it knows about, so it always 
looks like it knows exactly where it is. This has the undesirable 
property that track logs may be considered derivative works of the map 
held in the GPS.

As I understand it, pretty much all USB GPSes, especially "USB mouse" 
ones, present as a generic serial device which shows up in Linux as 
pl2303 or similar, which just spits out NMEA sentences every second.

I'll report more on this when my new toy arrives :-)

Christian / cjb

http://www.cjb.ie/