TransDEM Forum

G'day geophil,

Roland, I know you have publicly stated in the past regarding the accuracy of certain parts of the MSR (former USGS) maps that we use to create our American routes, here, describing certain quads of their maps as being "less than perfectly placed" and although I have come across a few 'errors' of this type in my own travels, I have to admit that this is a "woozy". I can only hope the the person responsible for this "hash-up'...



...has been summarily placed against a wall and shot...

......is there any alternative map source that I might be able to use that will allow me to continue with my route (with these same topographic maps - correctly georeferenced)?...

Jerker {:)}

Rumours say students and interns had scanned the paper maps and they had made mistakes. One of the more prominent ones can be found at Tehachapi (town, not loop), Calif.

Yes, there is a second source which includes georeferencing: USGS Seamless Server. You will find them hidden in the "Modify Request" dialog under "Scanned Maps". They will be in GeoTIFF format and TransDEM should be able to read them.

G'day geophil,

..."you pay peanuts (although these students and interns you mention probably weren't), you get monkeys"...

...I shall go digging, Roland...

..thank you, Sire...

Jerker {:)}

G'day geophil,

Roland, I have spent the last hour or so following your suggestion above and although I found the place to look with ease, I am unable to obtain any result other than the message "There are no products available in the area you indicated", despite trying each of the four options available (and All four, simultaneously) on different occasions. I find this 'intriguing', surely, the maps would be available for Nevada?. I even tried alternative area selection criteria, all to no avail, as well as trying a different 'location'. What am I doing wrong?..

Jerker {:)}

You are right. I don't get anything any more either.

Well then, time for a bit of research. According to the Seamless Server front page, DRG is gone (note from June 22nd) and they point to Earth Explorer - to no avail. However, they also mention a DRG web mapping service, and voilà, there we are.

Here is our new data source: TransDEM settings USGS WMS DRG.

G'day geophil,

Thanks for that, Roland. However, I still have a problem. Despite adding the *.xml file as per your instructions (which, incidentally, worked perfectly), I am now only getting 'blank' maps (no matter which of the map options I choose from the selections available)...



...now what's the matter?...

Jerker {:(}

My quick test was for a place in New York state. Worked like a treat there. Nevertheless, looking closer it appears that there are no coordinate systems for the western states. That's a definition in the WMS meta data file. This could mean that the map data itself is not yet there or that the meta data is incomplete. I will analyse the remaining spatial reference codes in the meta data for something legible. A quick look didn't bring up anything useful, though. The whole service is marked as new. Could be teething problems.