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US National Map Historical Topographic Quadrangles
https://forum.transdem.de/viewtopic.php?f=8&t=541
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Author:  WindsorSpring [ 08 Oct 2018 21:46 ]
Post subject:  US National Map Historical Topographic Quadrangles

I have recently tried to download 7.5-minute 1:24,000 quadrangles from the US National Map and noticed the only option offered on the original TNM download browser page is GeoTIFF. Simply clicking on the "download" will get you a GeoTIFF. Alarming, because my version 2.6.0.1 does not read that format and, of course, neither does Acrobat.

However, I clicked on the "Metadata" option and that opened a new browser page listing all the metadata for my topographic map. Halfway down the page is the "Downloads" section. It offers two choices: GeoPDF and GeoTIFF with appropriate links. I am happy to report clicking on the GeoPDF option gave me a 7.5-minute quadrangle that TransDEM 2.6.0.1 was able to georeference the way I have been accustomed.

The National Map Download page offered GeoPDF files when I attempted downloads in May 2018, so there was no problem at that time. Has anyone else had this experience? The work-around was fairly simple to use and I hope my sharing it will be helpful.

Author:  geophil [ 09 Oct 2018 12:50 ]
Post subject:  Re: US National Map Historical Topographic Quadrangles

I can confirm this observation. Looks like a bug in the TNM viewer query processing to me. Have you contacted them?

Author:  WindsorSpring [ 09 Oct 2018 16:36 ]
Post subject:  Re: US National Map Historical Topographic Quadrangles

I have not contacted USGS yet, but I will let them know. I will share what I learn with this community.

Author:  WindsorSpring [ 10 Oct 2018 01:28 ]
Post subject:  Re: US National Map Historical Topographic Quadrangles

Here is a note I received this afternoon that supports geophil's guess:

"Hello,
There is a temporary issue with the database that is not providing links to the GeoPDF files. It has been reported but in the meantime, you can access the GeoPDF download by clicking the Info/Metadata link in the Results list. On the page that comes up, you will find links for the GeoPDF and GeoTIFF. Another option for the Historical Topographic Maps is our TopoView site which is specifically for the historical maps with 4 formats available (JPG,GeoTIFF,GeoPDF & KML) "

This makes sense. I will keep checking on this.

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