[GRASS-user] gdalwarp latlong to UTM

[Hamish]

Gary wrote:
> I've tried using gdalwarp to convert from latlong to UTM. I used this 
> format, as pulled from the remotesensing.org website:
> gdalwarp -t_srs '+proj=utm +zone=11 +datum=WGS84' raw_spot.tif
> utm11.tif
> 
> After conversion, r.los believes the new file is still in latlon
> format.  [I used the override option.] I tried using the -te option,
> but can't seem to get gdalwarp to accept it.


The general steps:

* create a new UTM location in GRASS.
* restart GRASS in that UTM location.
* "pull" the map over from the lat/lon location using r.proj.
* run r.los, etc.


In GRASS the location sets the projection info, not a single map's
meta-data. r.los won't work because you're still in a Lat/Lon location,
not a UTM one.

You only really need gdalwarp from within GRASS if you want hi-tech thin
plate spine warping or you want to automate a large batch process.
Otherwise you are just making extra work for yourself.


Hamish