Digital

About 180,000 USGS historical topographic maps (more than 95% of those ever published) are available to the public free of charge, and the number of maps available is still growing. This set of GeoPDF files is referred to as the Historical Topographic...
That depends on what kind of reprojection you want to do. In some cases, if you want to reproject from one datum to another (specifically NAD 27 to NAD 83 or NAD 83 to NAD 27), a simple xy shift will suffice. This shift will not introduce measurable...
Yes, customers will need to acquire at least 2 consecutive digital images from the same roll and then create transparencies or contact prints to view them with a stereoscope. A stereoscope is a device for viewing a stereoscopic pair of separate images,...
A feature is something shown on a map, and it has characteristics or properties, which can be represented in feature-based Digital Line Graph (DLG) data using attributes and values.
Yes.  Scanning of the EROS film archives is following a plan to capture images from rolls at risk of decay from vinegar syndrome. Science requirements are also reviewed on a regular basis, but a formal, on-line schedule is not available at this time....
You can purchase topographic maps several ways:1) Download or online from the USGS Store.Click on "Maps" in the left margin or click on the "Map Locator" near the center of the screen.  Topographic maps in GeoPDF format are available for free download by...
Geographically, and as a general reference, the United States (short form of the official name, United States of America) includes all areas considered under the sovereignty of the United States, but does not include leased areas.On May 14, 1959, the U.S...
After the completion of the original 7.5-minute map series in 1992 and until late 2008, the USGS mapping program focused on creating national geographic information system (GIS) databases. In November 2008, USGS management committed to design and produce...