[plug] GPS and maps

[Tim Bowden]

On Thu, 2007-04-19 at 20:18 +0800, William Kenworthy wrote:
> Just got myself a cheap GPS to use with my treo. Are there any useful
> maps of Perth and surrounds available?
> 

Yes.  WA Govt provides bucket loads of geospatial data through the SLIP
(Shared Land Information Project) using OGC (Open Geospatial Consortium)
standards, namely wms (Web Map Service; Raster Data) and wfs (Web
Feature Service; Vector data).  You will need to register to get the
data (http://www2.landgate.wa.gov.au).  The service is still in pilot,
but I believe they have recently relaxed the limit on number of
subscribers to the service.  If you register, let me know of list and I
can give you a few pointers as to how to use it.

You will need a wms/wfs capable client to access the data
(http://udig.refractions.net which is also capable of viewing gps data).
What format do you need for your maps?

> GPSdrive under linux looks ok, but the supplied maps dont scale
> accurately (at one point, a location in Vic Park was rather wet - west
> of Rottnest) - the GPS seems accurate, its the software!  I will scan a
> map I have and see if its any better that way.
> 
> Speaking of which, google maps seem hundreds of meters out at times, the
> web based mapquest was two streets away (seems to be a
> precision/rounding error) - much of the software (linux and palmOS)
> seems quite old, not a good state of play :(
> 
> BillK
> 
> 

Google images are sometimes of questionable accuracy, and their utility
depends on what the accuracy you need. 

For a run down on GIS (Geographic Information System) software for linux
(of which GPS is a very small part), try http://freegis.org.  In
particular:

http://www.gpsbabel.org/ for converting gps data between many common
formats

http://gpsd.berlios.de/ gps unit daemon for providing data to multiple
apps (site down atm, and expecting to move soon I believe).

http://postgis.refraction.net Spatial extension to postgresql rdbms
providing ogc compliant spatial objects and operations.

http://www.qgis.org/ GIS desktop application.  Good for viewing and
manipulating data, but can't (yet) do wfs.

http://www.openstreetmap.org Community built maps (think wikipedia), but
no data yet for WA.

http://www.osgeo.org World wide open source geospatial foundation.  The
main discuss mailing list is a great place for asking general questions
about open source GIS in general.  Will often result in being pointed to
the appropriate projects mailing list.

http://wiki.osgeo.org/index.php/Australia  Australian Chapter of OSGeo
(in formation).  Questions about open source gis in Aust welcomed on the
mailing list.

http://lists.burri.to/mailman/listinfo/geowanking Geowanking mailing
list: Open source friendly, a good place for asking any type of general
gis/gps questions.


HTH,
Tim Bowden

-- 
Mapforge Geospatial
Level 3, 267 St Georges Tce
Perth, 6000
Western Australia
Ph: 08 9261 7780
Fax: 08 9261 7700
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