The use of Portable Document Format (PDF) files to store maps and imagery—along with embedded metadata to georeference these geospatial assets—generated significant interest across various agencies and departments within the U.S. Government. While discussions about “electronic” charts and maps were already underway, LGIView and PDF maps with embedded geospatial metadata represented one of the earliest concrete realizations of this concept. Leading this effort was the National Geospatial-Intelligence Agency (NGA), which at the time was known as the National Imagery and Mapping Agency (NIMA).

The SBC project required embedding geospatial metadata into individual files, along with interactive features such as hyperlinks. It also anticipated the need to convert between different geographic coordinate systems. However, NGA outlined requirements that went beyond the earlier LGIView work: the goal was to achieve “full geo” capability. This meant enabling conversions to and from arbitrary geographic coordinate systems, displaying World Geodetic System 1984 (WGS 84) latitudes and longitudes, and showing the Military Grid Reference System (MGRS) regardless of the map’s underlying projection. LGI initially named the internal specification for geospatial metadata used in the SBC project “GeoPDF 1.0.” However, to meet NGA’s more advanced requirements, they developed a new metadata specification, which became GeoPDF 2.0 in 2004. Since then, this specification has been refined and recognized as a best practice by the Open Geospatial Consortium (OGC), codified by the Library of Congress, and others.

While geospatial standards were being developed by organizations like the OGC, these standards were often complex, evolving, and focused on layered hierarchies to bridge geospatial data and applications. LGI had to strike a balance between adhering to these evolving standards and the practical need to build applications capable of converting and displaying coordinates, as well as performing related calculations. The U.S. Army Corps of Engineers developed a geospatial translation engine called “GEOTRANS,” based on NATO standards. LGI adapted the inputs from GEOTRANS into the parameters of its GeoPDF 2.0 specification. GEOTRANS powered the GeoPDF Toolbar and other GeoPDF software. Since this software was produced by the U.S. Government and released as open source, it encouraged early adoption by agencies such as NGA, the U.S. Army Corps of Engineers, and the United States Geological Survey, among others.

As demand grew for GeoApps that could be assembled from different systems and deployed to users without specialized geographic information system training, the U.S. Government and other organizations demonstrated both interest in and requirements for electronic methods of creating and distributing maps and imagery. This created an opportunity to expand beyond what Layton Graphics had achieved with the SBC project and LGIView. To pursue this, LGI spun off TerraGo in 2005.

In our next installment, we will explore how GeoPDF is not simply a “format” or a “specification”—it is an entire ecosystem.