[GRASS-user] gps import: definition of WGS84

Hamish hamish_b at yahoo.com
Sat May 24 02:14:01 EDT 2008

> I'm not sure what the implications are in this context,
> but any valid PROJ.4 coordinate system ought to include
> the ellipsoid definition - either directly or via the
> datum parameter.  So if the coordinate system is
> intended to be WGS84 I'd encourage it to be declared as
> "+proj=latlong +datum=WGS84" rather than
> "+proj=latlong +towgs84=0,0,0".
> In normal practice a default ellipsoid of WGS84 is used,
> and in combination with +towgs84=0,0,0 this would be
> equivelent to +datum=WGS84 - but why risk the defaults
> file not being found?

ok, proj strings updated in SVN for scripts that call cs2cs.

(I take it there is no difference between latlong and longlat? ie it  always assumes input is x,y unless you use proj/cs2cs -r ?)

$ proj -l
lonlat : Lat/long (Geodetic)
latlon : Lat/long (Geodetic alias)



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