Acrobatic Mapping
ARMY TOPOGRAPHIC CENTER LEVERAGES GIS/MAP DATA USING ADOBE’S UBIQUITOUS PDF DOCUMENT FORMAT.
The Army Corps of Engineers addresses issues ranging from water resources to national infrastructure and homeland security, as well as ongoing support of America’s troops at war. In support of those missions, the Corps’ Engineer Research Development Center’s Topographic Engineering Center (ERDC/TEC) has discovered innovative ways to leverage GIS/map data using PDF, the popular Adobe Acrobat document formatting standard.
TEC was introduced to the GeoPDF file format about two years ago by Patrick Biggar of the St. Louis, Mo., office of the National Geospatial-Intelligence Agency (NGA). NGA had been looking for better ways to replicate and distribute their products and create digital map display files that were more useful, accessible and offered better resolution, while maintaining the “small” file size of the Compressed Arc Digital Raster Graphics file format that the military currently uses.
In 2004, NGA representatives were introduced to the idea of geo-referenced PDF (GeoPDF) by the creators of the file format TerraGo Technologies, then known as Layton Graphics. NGA liked the idea and began to look into it further. As NGA investigated, officials liked it even more and began the eChart initiative. They approached TEC and asked if there was interest in helping test this new file format.
Most organizations that utilize geospatial data have very valuable information locked inside complex applications that a small number of professionals understand and know how to use, and TEC is no different. TEC has geographers, physical scientists and engineers who are trained to use complex GIS applications and capabilities, but who also need the ability to share georeferenced maps and data with professionals who aren’t GIS application-savvy.
MAP2PDF, the TerraGo Technologies product line, leverages the ubiquitous Adobe format standard to provide a portable mapping format known as GeoPDF. Utilizing MAP2PDF, TerraGo customers are able to create and publish layered, georegistered maps. Users simply create a map and use MAP2PDF to export the data to a GeoPDF file, which can be distributed to non-GIS professionals who utilize Adobe Reader to view maps, turn layers on and off, query attributes, display coordinates and create redlines and notes.
GeoPDF files can be sent to all kinds of field personnel, from engineers on the scene of natural disasters like Hurricane Katrina to soldiers in the field who can utilize Adobe Reader to manipulate the maps. No special training is required, and most computers come with a reader already installed. So a simple, free plug-in from TerraGo is the only requirement for command chain users to view the GeoPDF map. Files are small and nimble, yet are embedded with powerful capabilities that allow engineers to work in connected or disconnected modes.
GEO-REFERENCED DATA
TEC was impressed with the GeoPDF concept, which provides a standard format for use and exchange of geospatial data with non-GIS/mapping users. It is a standalone file, with image, text, fonts, graphics, customer data, GIS data and metadata all contained within the file. The data is georeferenced, and the software viewer is free and already on over 700 million computers worldwide.
Given all of this, we began the Army GeoPDF project, which is now ongoing. We contacted Headquarters Marines to let them know what we were up to, and they jumped on board. We are now able to easily create products using the data we have and deliver that information up and down the command chain in a familiar file format that works with a viewer already loaded on their computer.
There are two types of GeoPDF files, raster GeoPDF and vector GeoPDF, as well as two ways to create GeoPDF files. Both file formats provide a scalable display of the digital map, with crisp, clear delineation of roads, rivers, contour lines and other features as the user zooms in for a closer look. The raster files are paper maps that are scanned or existing electronic files of those maps that are saved in a PDF format and geo-referenced using the TerraGo MAP2PDF plug-in for Adobe Pro. The vector GeoPDF format has an added function that enables users to turn layers on and off as needed to analyze a map display based on the user’s needs. It is produced by using the MAP- 2PDF for GIS extensions for ESRI’s ArcGIS 9x and Intergraph’s GeoMedia and Digital Cartographic Studio.
TEC has begun to create unclassified/ for official use only GeoPDF country DVDs for regions of the world. The GeoPDF files are small, with most ranging from two to 10 megabytes per map.
We began this project by taking all of the NGA standard map sheets for a test country, scanning and converting them to GeoPDF files, and packaging them with an index sheet for easy use. It was an instant hit with everyone. Having NGA products on one DVD for use in a demand-based replication environment was an astonishing sight for most people.
While working with the Army Terrain Teams, we saw more that could be done with GeoPDF, but only if ArcGIS, Imagine and military free software FalconView could read the GeoPDF format. And this functionality could be leveraged even more if we could mosaic 2, 4, 10, 20 sheets for a map background.
I have spent many months working with TerraGo Technologies, ESRI, Leica and the FalconView program to enable the GeoPDF format to be read by mainstream GIS packages. I can report that TEC has funded FalconView to do so and is having an extension for ESRI’s ArcGIS created that will read in a GeoPDF file, the extension will be free to all in the DoD and available by May 2007. Leica has also expressed interested in working with TerraGo in reading and writing a GeoPDF extension.
As we wait for the major GIS software companies to embrace this file format, TEC has created a tool to convert GeoPDF files to GeoTIFFs so they can be read into a GIS. As for mosaicing 2, 4, 10, 20 sheets for a map background, we have paid for some of the development of a new TerraGo tool called Map Assembler that does just that.
COUNTRY MAPS
We have created DVDs for five countries so far and are distributing these to the military. Because NGA is converting the Research Center’s map holdings (standard NGA products) to GeoPDF, TEC will be able to create 46 more country DVDs by this spring. We obtained all 60,000 U.S. Geological Survey DRG files and have converted them into GeoPDF documents using the TerraGo tool GeoTIFF2GeoPDF, which TEC helped fund.
We have given the GeoPDF files to USGS, which will make them available free via the USGS online store. We have started to convert all NGA’s Arc Digital Raster Graphics (ADRG) into GeoPDF; ADRG covers most the world at different scales—1,000,000 scale for most of the world, down to 25,000 scale for small areas around the world.
TEC also has begun to convert our Urban Tactical Planners into layered vector GeoPDF files and will also produce all future UTPs with the format. TEC will also begin converting all Engineering Route Studies from PDF to GeoPDF in the coming weeks. All Army Terrain Teams have the MAP2PDF Adobe Pro plug-in and the MAP2PDF ESRI extension (for creating GeoPDF files) and have recently received the tools to convert the GeoPDF files to GeoTIFFs, as well as the Map Assembler so that they can begin to produce missionspecific products that are saved as GeoPDF files.
Every Global Geospatial Intelligence contract that NGA signs has a provision that requires a vector GeoPDF to be produced as a map sheet is created. We are waiting for the delivery of these vectorbased GeoPDF files so we can rotate them into our country DVDs, replacing the inferior but usable raster files.
NGA is also using GeoPDF maps in the Geospatial Contingency Packages that are being created for the State Department and for the new Marine Corps map atlas. ♦
