[Qgis-user] Newbie: How do I project DEM file?

[Donovan Parks]

Hello,

I am new to Qgis and GIS in general so please excuse any butchering of
terminology. I have a DEM file of the Atlantic seaboard that I wish to
view in Qgis. I can easily load in a view the map without problem.
Now, from what I understand, the default projection in Qgis is
"latlong". I'd like to change this to WGS84 / World Mercator which I
can easily do through the project properties dialog. I also make sure
on the fly projection is enabled here. My understading is that his
will now take my DEM and project it using the WGS84 / World Mercator
projection. However, when I do this the DEM map "disappears". I have
tried right-clicking on the map layer and zooming to layer extents,
but this doesn't help.

What is more surprising, is that I am also loading in a collection of
lat/long values in a CSV file. These appear to be projecting just fine
(at least they don't disappear and they seem to be influenced by the
projection). I've tried a number of different projections with the
same results. Namely, the loaded lat/long values seem to be projected
correctly, but the DEM is nowhere to be found. Is it not possible to
project a DEM in Qgis? Is there something I need to do to my DEM
before projecting it?

I'm lost at what is going on here. Any and all help would me much appreciated.

Thanks,
Donovan