I am working on combing and compiling the data for a WA state map. I have been following the tutorial religiously, but I can't figure out the Datum.
What datum does all of this data use? I have assumed, that since it is coming straight from the source, that it is using NAD83, is that correct? If not, then I would have to tell my GPSr what datum to use, correct?
I was reading about the combining data. In the tutorial, step 4 states "Click "Add Files..." and open the "dem" folder and then click the top dem file then hold shift and select the bottom file. This will select all the dem files created previously."
I would assume that this means to select only the *.gmp (global mapper) or *.mp (dem2topo) files that were created for elevation lines.
Is this correct? Or do you really mean all the files copied from the ArcGrid or GeoTiff files downloaded from the seamless server?
I'm a noob at this, but have decided to try to follow Oz's excellent tutorial and make a topo of WA state. I have begun downloading and processing all the NED files. Hopefully will be finished by the end of the week and can get started on the NHD files.
How long does it usually take to start getting NHD files after the request is submitted? I submitted some requests 2 days ago and have yet to hear anything.