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GeoPDF File Format (TerraGo)

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Format Description Properties Explanation of format description terms

Identification and description Explanation of format description terms

Full name GeoPDF File Format (TerraGo)
Description

GeoPDF® is a trademark registered to TerraGo Technologies, Inc. [Serial #: 78655318]. TerraGo insists that the term GeoPDF should be reserved for files created by TerraGo products; this description covers such files. See What is GeoPDF? and GeoPDF Products from TerraGo. TerraGo does not provide a detailed specification but claims compliance with existing documentation for PDF as specified in ISO 32000. There are two versions of this international standard, published as Parts 1 and 2 of ISO 32000:

  • ISO 32000-1:2008, Document management -- Portable document format -- Part 1: PDF 1.7 (see PDF 1.7)
  • ISO 32000-2. Document management – Portable Document Format – Part 2: PDF 2.0 (see PDF 2.0). Note that this specification is "also suitable for interpretation of files made to conform to any of the previous Adobe PDF specifications 1.0 through 1.7 and ISO 32000-1."

The compilers of this resource have not yet located any GeoPDF files that have the new version designation defined in PDF 2.0, %PDF–2.0. Comments welcome.

TerraGo's GeoPDF products are designed to facilitate sharing complex multi-layer maps and imagery to provide easy access and geospatial collaboration capabilities to non-GIS professionals. A press release in March 2020 for an update to TerraGo's main authoring tool for GeoPDFs, stated, "GeoPDF documents made with TerraGo Publisher for ArcGIS can be used with the TerraGo Toolbar. They also can be extended to Adobe Acrobat Reader to provide a host of GIS-lite capabilities. These capabilities include an Identify Tool, simultaneous display of multiple geographic coordinates, measurement and geospatial markup." A GeoPDF MapBook Help Page from the Missouri National Guard shows the functionality of the Toolbar in 2010. The TerraGo Toolbar, renamed the GeoPDF Toolbar later in 2020, is a freely downloadable add-on to Adobe Acrobat Reader available for the Microsoft Windows operating system. There is no documentation available to specify exactly how Terrago uses structures specified in ISO 32000 to implement features supported by the GeoPDF Toolbar. Some indications can be gleaned from: TerraGo Publisher for ArcGIS Server - Automation with PubPy. PubPy is a Python software library that allows an Esri ArcGIS Server to be programmed to "create on-demand GeoPDFs containing maps and imagery embedded with your intelligence and data." TerraGo offers a GeoPDF® Software Development Kit (SDK) but has no associated public documentation.

In addition to complying with ISO 32000, a GeoPDF file must incorporate one of two supported georegistration encodings:

  • The encoding for georegistration specified in PDF Georegistration Encoding Best Practice Version 2.2 published by the Open Geospatial Consortium (OGC) as OGC 08-139 in 2009. This encoding was developed by TerraGo's predecessor company in the early 2000s and submitted by TerraGo to OGC. For more details, see description at GeoPDF_OGC. TerraGo refers to this as the OGC encoding.
  • The encoding for georegistration supported by Adobe in Acrobat 9 and originally specified in PDF, Version 1.7, ExtensionLevel 3, Geospatial Encoding, published by Adobe in June 2008. This encoding was incorporated into ISO 32000-2 (aka PDF 2.0), published in 2017. See description at PDF_1_7_geospatial. TerraGo refers to this as the ISO encoding.

A primary intended functionality of georegistration is to support calculation of the position in coordinates of any point on a map image and thus to associate PDF annotations and linked files with a particular geospatial location and to support measurement between points. Point locations can be expressed in any coordinate reference system and the two supported encodings include sufficient information to perform conversions between coordinate systems. The OGC and ISO georegistration methods both encode the same information; however, more coordinate systems are supported using the ISO georegistration encoding. See lists of coordinate systems provided by TerraGo at OGC Projections and Datums and ISO Projections and Datums. TerraGo software is capable of reading and writing both encoding methods.

In his February 2009 blog post, OGC Approves GeoPDF 2.2 as OGC Best Practice, George Demmy of TerraGo recommended, "If you'd like to roll-your-own geospatial PDF, I'd recommend using Adobe's proposed geospatial extensions to ISO 32000. Our software supports this georegistration technique, and we're already moving in that direction." The compilers of this resource have not attempted to determine the relative adoption of the two approaches to georegistration in GeoPDF documents. Comments welcome.

TerraGo's GeoPDF Publisher for ArcGIS and GeoPDF Composer offer three compatibility options related to georegistration:

  • GeoPDF Toolbar 3+ (OGC). To use the OGC georegistration encoding. TerraGo states, as of 2020, that "the OGC best practice is the most widely distributed georegistration encoding in terms of existing PDF libraries and workflows because GeoPDF was the only geospatial PDF available preceding the release of Acrobat 9."
  • GeoPDF Toolbar 5+ (OGC Preferred). To attempt to use the OGC geoegistration encoding. If the selected coordinate system is not supported in the OGC encoding, use the ISO 32000 encoding. This is the default choice.
  • GeoPDF Toolbar 5+ (ISO Only). To use the georegistration encoding from ISO 32000.

An important feature of GeoPDF files is the ability to contain data payloads associating attributes with points or areas on a georegistered image or map. Application domains include emergency management, and management of natural resources and remote assets such as utility poles and railway track. GeoPDF files with such data payloads can support accurate geospatial reference, access to existing data, and the collection of information in the field associated with a location on a map. An example application is described at Sebring Water Utility Sends iPads onto the Field to Save Money and Improve Service. There are two mechanisms for incorporating this data: PDF object data and feature attributes stored in a file in the GeoPackage_family. Depending on which mechanism is employed when creating the GeoPDF, users may be able to view some attributes using regular features of Acrobat Reader but the richer set of features added by TerraGo's GeoPDF Toolbar is required for full functionality. GeoPackage is a standard published by OGC; see https://www.ogc.org/standards/geopackage. The GeoPackage option was introduced with version 7.0 of the TerraGo Toolbar; see 2016 announcement. Reasons given included: (1) to provide a means to share and repurpose data used to make the GeoPDF map, in that anyone with software that understands PDF file attachments can pull the GeoPackage out and use it for other purposes; and (2) to address performance concerns and implementation limits of PDF object data. The GeoPackage data supports the Identify tool in the GeoPDF Toolbar; this toolbar, which requires JavaScript to be enabled in Acrobat Reader, allows users to search, display, and edit the embedded feature attributes. For information about the two mechanisms for incorporating such data in a GeoPDF, see Configuring Attribute Export Options, How do I access object data/attribute data in a GeoPDF map? and How do I get attribute data into my GeoPDF?. If a GeoPDF uses the GeoPackage mechanism, the GeoPackage file can be extracted from the GeoPDF using Acrobat Reader without the GeoPDF Toolbar. Comments welcome.

TerraGo does not provide documentation for how the GeoPDF format uses PDF structures and JavaScript to support the functionality in the GeoPDF Toolbar. TerraGo's GeoPDF Toolbar has undergone fairly frequent updates in recent years as shown in the cumulative TerraGo Toolbar Release Notes. Several of the 7.x releases since 7.0 in 2016 were to enhance functionality and not simply to fix bugs. It seems probable that they were accompanied by modifications to the GeoPDF file format as created by corresponding updated versions of the products for creating GeoPDF files. For example, the Release notes for TerraGo Publisher for Raster indicate that a new naming scheme was introduced in version 7.0.1 "when processing CADRG and other RPF formats with multiple images." TerraGo has often introduced new versions of the primary GeoPDF authoring tools, Publisher and Composer, at the same time as a new version of the Toolbar. For example, Version 7.6.1 of all three products was released in December 2019. Publisher for ArcGIS Pro was updated in March 2020 to support an update to ArcGIS and again in July; see cumulative release notes. According to TerraGo's presentation at the 13th Geospatial PDF Working Group – U.S. Federal Government meeting on August 5, 2020, new versions of products will be released in late 2020, introducing further features. It is important to note that many of the features of the GeoPDF Toolbar will not work unless the copy of Adobe Reader is configured to allow JavaScript to be executed. Features that depend only on the capabilities of Adobe Reader, such as turning layers on and off or extracting attachments, will operate without JavaScript enabled. The compilers of this resource would welcome any comments related to understanding of how GeoPDF file structures may have changed with different versions of the GeoPDF suite of tools and how different GeoPDF versions might be identified internally.

Relationship to other formats
    Subtype of PDF_family, Portable Document Format
    May contain PDF_1_7_geospatial, PDF, Version 1.7, ExtensionLevel 3, Geospatial Encoding (Adobe). A GeoPDF file must incorporate georegistration. The encoding for georegistration first published by Adobe in PDF 1.7, ExtensionLevel 3, has been incorporated into ISO 32000-2 and is one of two options for GeoPDF files.
    May contain GeoPDF_OGC, GeoPDF Encoding (TerraGo 2.2), OGC Best Practice. A GeoPDF file must incorporate georegistration. The encoding developed by TerraGo for georegistration was published as a best practice by the Open Geospatial Consortium (OGC) in 2009 and is one of two options for GeoPDF files.
    May contain GeoPackage_family, GeoPackage Encoding Standard (OGC) Format Family

Local use Explanation of format description terms

LC experience or existing holdings The compilers of this resource are not currently able to determine how many GeoPDF files have been added to the Library of Congress collections. A set of USGS Quadrangle maps in this format was acquired in 2012.
LC preference The Library of Congress Recommended Formats Statement (RFS) designates GeoPDF as an "acceptable" format for GIS Vector and Raster Combined content for GIS, Geospatial and Non-GIS Cartographic collections. The RFS does not specify a version of GeoPDF file format or a PDF georegistration within GeoPDF files.

Sustainability factors Explanation of format description terms

Disclosure

There is no detailed documentation on how TerraGo software uses the capabilities of PDF to support the functions of the TerraGo GeoPDF Toolbar.

    Documentation

TerraGo states that GeoPDF files created by its software (stand-alone products or libraries or toolkits that it licenses for integration into products from other vendors, such as Esri or BAE) comply with one of the two ISO 32000 international standards for PDF and use one of two publicly documented georegistration encodings.

According to TerraGo, a GeoPDF file will comply with one of these PDF specifications:

  • ISO 32000-1:2008, Document management -- Portable document format -- Part 1: PDF 1.7 [PDF_1.7]
  • ISO 32000-2:2017, Document management -- Portable document format -- Part 2: PDF 2.0 [PDF_2.0]

and use one of these georegistration encoding mechanisms:

  • GeoPDF Encoding (TerraGo 2.2), OGC Best Practice [GeoPDF_OGC]
  • PDF, Version 1.7, ExtensionLevel 3, Geospatial Encoding (Adobe) [PDF_1_7_geospatial]
Adoption

TerraGo Technologies has worked with Esri, other vendors, and customers, to develop a suite of software tools that create GeoPDF files and support their use; in particular, these files can be used in the field via the GeoPDF Toolbar or TerraGo Edge apps for iOS or Android mobile devices to check existing data about equipment items, land parcels, etc. and add annotations in the field that can be fed back into a GIS database. See TerraGo releases GeoPDF Software Suite Version 7.0 and GeoPDF® Products. The main products for creating GeoPDF documents are GeoPDF Publisher, available as an extension for ArcGIS Pro, and GeoPDF Composer, an extension for Adobe Acrobat. A GeoPDF Software Development Kit (SDK) is also available. GeoPDF Toolbar is a free plug-in for Adobe Reader that allows anyone to access, update and share GeoPDF maps and imagery; its functionality is often described as "GIS-lite."

Some GIS software vendors support integration of TerraGo modules into their products and can therefore generate GeoPDF files. For example, add-ons for Esri products include GeoPDF Publisher for ArcGIS Pro and GeoPDF Publisher for ArcGIS Server. BAE Systems has integrated TerraGo 2D GeoPDF Publisher into its SOCET GXP product. Many GIS applications can import and display GeoPDF files and extract layers or convert a GeoPDF map to another format but are not able to reproduce the advanced functionality of the GeoPDF Toolbar.

Several U.S. government agencies have produced and distributed maps as GeoPDF files, including the U.S. Army Corps of Engineers, and the National Geospatial-Intelligence Agency. For example, see:

Starting in 2009, the United States Geological Survey (USGS) began to publish two new map products in digital form. The first product was an end product of a digital workflow for generating the equivalent of standard USGS printed maps at 1:24,000, known as US Topo maps. The second product was for scanned versions of USGS Historical Topographic Quadrangle maps, dating back to 1884. Both products initially used Terrago GeoPDF files as a format for distribution of digital maps for public use. In 2017, the current US Topo maps were migrated to specifications based on the ISO 32000 encoding for georegistration (see PDF_1_7_geospatial) as introduced with Acrobat 9.0 in June 2008. For the file specifications from USGS, see http://pubs.usgs.gov/tm/tm11b2/ for the US Topo Product Standard and https://pubs.er.usgs.gov/publication/tm11B03 for the Standard for the U.S. Geological Survey Historical Topographic Map Collection (HTMC). The HTMC collection continues to use GeoPDF files with the OGC encoding for georegistration.

The GeoPDF format is a key component in several projects and partnerships in specific domains where TerraGo is developing software to support field operations. One active domain is management of street lighting by municipalities. See for example, TerraGo Streetlights; TerraGo and Urban Control partner for intelligent street lighting, and Itron Signs Global Reseller Agreement with TerraGo to Accelerate Smart Streetlight Projects. Another domain is management of equipment assets by utilities. See for example, TerraGo Smart Utilities and Arrow 100 for Pipeline Data Collection: Enmapp Saves Thousands by Switching to TerraGo Edge with Eos.

The GeoPDF format is accepted by the National Library of Australia for legal deposit. See What file format should I deposit?.

    Licensing and patents

GeoPDF is a registered trademark of TerraGo Technologies, Inc. with serial number 78655318. See https://uspto.report/TM/78655318 for details and history. With relation to the georegistration encoding published as a Best Practice by Open Geospatial Consortium, OGC 08-139r3 includes the statement, "This specification is being provided by TerraGo on a reasonable and non-discriminatory, royalty free basis (RAND-RF)."

See PDF_family for patent and licensing information associated with PDF.

Transparency Depends upon compliant software tools to read. Building tools requires sophistication. In practice, most PDFs have compression filters applied to most of the file content. Image compression depends on underlying image format and options chosen when GeoPDF is created. Vector layers can also be compressed; see Vector Options in GeoPDF Publisher knowledge base.
Self-documentation

A GeoPDF file must have georegistration information, providing limited geospatial metadata for maps or other georegistered illustrations in a PDF file, sufficient to support geolocation and measurement. Since the GeoPackage format has had a registered extension for Metadata since GeoPackage 1.1, it is possible that GeoPDF files can include metadata complying with ISO 19115 using that mechanism. ISO 19115 has been endorsed by FGDC (U.S. Federal Geographic Data Committee). According to TerraGo's presentation at the 13th Geospatial PDF Working Group – U.S. Federal Government meeting on August 5, 2020, the company is developing new capabilities for embedding metadata into GeoPDF files. See PDF_family for information on embedding metadata in PDF documents in general.

Accessibility Features

Accessibility features for GIS data can be a complex combination of factors to support still images, 3D formats, and datasets. In general, this means data to alt text for images, content for screen readers to enable user interactivity events such as object selection, rotation and zoom, alt text for image forms, color contrast definition as well as caption and subtitle support as well as structured data to identify regions and grids on pages and defined relationships in tables. Depending on implementation, GeoPackage files have the potential for good accessibility support with its defined structures and focus on interoperability but this will also depend on the subtypes.Comments welcome.

Also see PDF_family for more information on PDF file support for accessibility.

External dependencies

A GeoPDF file must be created with a software product or tool developed by TerraGo. See GeoPDF Products.

Users of GeoPDF files who do not have a full GIS system that supports GeoPDF files need the TerraGo Toolbar, an add-on to Adobe Reader, to get full value from a GeoPDF file. The toolbar is freely downloadable (after registration), but works only on Windows. For mobile devices, there is the TerraGo Edge app; this app is designed for data capture in the field, but can also be used as a viewer for GeoPDF maps. See TerraGo Edge 4 on Apple's App Store and on Google Play.

Technical protection considerations Since GeoPDF files are PDF files, they can be protected using techniques available in Adobe Acrobat, for example, using passwords or certificates. They can also be encrypted using generic tools for encrypting individual files.

Quality and functionality factors Explanation of format description terms

Still Image
Normal rendering See PDF_family for discussion of quality and functionality factors for images in PDF documents.
Clarity (high image resolution) TerraGo's GeoPDF Publisher for ArcGIS Pro uses a default of 300 dpi for image resolution, but optionally supports much higher resolution when creating a GeoPDF. A table in Understanding Output Resolution has a column for 6400 dpi. Color bit depth will depend on source image type and characteristics. Color space options are RGB and CMYK. See documentation in TerraGo Publisher for ArcGIS Server - Automation with PubPy.
Color maintenance See PDF_family.
Support for vector graphics, including graphic effects and typography Excellent support for vector graphics and symbology in vector layers.
Support for multispectral bands See PDF_family.
Functionality beyond normal rendering A GeoPDF file is always georegistered and can contain multiple layers.
GIS images and datasets
Normal functionality

TerraGo often refers to features supported in its GeoPDF Toolbar as providing "GIS-lite" functionality. The overview page from TerraGo for GeoPDF Toolbar lists some of the functionality supported. Video demos of the Toolbar functionality are available at How to use a GeoPDF from 2016 and Toolbar Tutorial Webinar from 2020.

Beyond normal functionality

A GeoPDF file can contain GeoMarks, points or areas marked on a map and associated with data, including stamps (icons with specific meaning), notes, photos, video and other multimedia. If the GeoMark Enable setting was turned on by the creator of a GeoPDF, GeoMarks can be entered or editid by crew in the field using the GeoPDF Toolbar, to document an incident, update inventory, etc. If the creator so chooses, GeoMarks can be completed in the field with the help of a form embedded in the GeoPDF. GeoMarks can be exported as shapefiles or in KML for efficient sharing among field operators or transmission to headquarters over low bandwidth networks. They can also be exported into a TerraGo proprietary file format known as TWZ and called a TerraGo Collaboration Package. See How do I view my GeoMarks in Google Earth or other systems? and GeoPDF Toolbar Tutorial. Note that TerraGo's GeoPDF Toolbar is distributed with an associated GeoMark Toolbar. The GeoPDF Toolbar is primarily used for working with existing information in a GeoPDF, whereas the GeoMark Toolbar is used, if GeoMarks are enabled, for adding or editing data attached to the GeoPDF and its use will modify the GeoPDF. Comments welcome.

A GeoPDF file can contain a mapbook, i.e, a collection of related maps, typically including an index map that provides access to the individual map pages. A special feature of GeoPDF mapbooks is that you can move seamlessly from one map to the next based on geospatial location. See TerraGo Products: GeoPDF Composer and video demos at TerraGo Composer: GeoPDF Mapbook Intro and Overview and TerraGo Composer: How to Create a GeoPDF Mapbook. A webinar that has a section on creating a mapbook is available at Composer Tutorial Webinar.


File type signifiers and format identifiers Explanation of format description terms

Tag Value Note
Filename extension pdf
 
Internet Media Type See note.  See PDF_family.
Magic numbers See note.  See PDF_family.
Pronom PUID See note.  No PUID as of August 2020.
Wikidata Title ID Q5533911
See https://www.wikidata.org/wiki/Q5533911 for GeoPDF as "file format extending PDF to allow for embedding georegistration information for maps".

Notes Explanation of format description terms

General

Terminology: This is an attempt to clarify some sources of confusion over terminology in the context of adding geospatial functionality to PDF documents.

  • Georeferencing and georegistration are both used to describe the process of associating points in an image or other layer of map data with coordinates in a chosen coordinate system. In this context, they can be considered equivalent; which term is used will depend on the author, or a choice made by a company or organization. See, for example, Overview of Georeferencing from documentation for ArcGIS Pro and Georegistration from the documentation for Manifold.
  • GeoPDF is a trademark, registered in 2006 and owned by Terrago. As stated in a blog post titled GeoPDF is not a Format on May 12, 2010 in George Demmy's "GeoPDF" blog, "Today, if a file is created by TerraGo software, it is a GeoPDF file. If it is not created by TerraGo software, it is not a GeoPDF file. This is definitional and the position of TerraGo." Since then, Terrago has maintained this position, which has been accepted by the Open GeoSpatial Consortium, which added "GeoPDF is a registered trademark of TerraGo Technologies and may only be applied to products created under license from TerraGo. GeoPDF products use the PDF geo-registration technique as described by this specification, but also may use other geo-registration encoding techniques, optimizations, and methods beyond the scope of this specification" to OGC 08-139r3, the 2011 revision of "PDF Geo-registration Encoding Best Practice Version 2.2." However, USGS presents a slightly different perspective at What is a GeoPDF®?, stating "The USGS currently produces topographic maps using an Open Source GeoPDF format. However, most digital USGS topographic maps published before June 2017 are GeoPDF® files that were produced using software from Terrago Technologies." The view expressed in GeoPDF (from course materials from the U.S. Naval Academy) is quite common: "Some purists say that GeoPDF applies only to the TerraGo brand products because they have a registered trademark, and others should be called a Geospatial PDF. A lot of people would say this is barking up the wrong tree, like Kleenex and Xerox, and this term should be a generic term and used like GeoJSON or GeoTIFF."

    As of 2020, Geospatial PDF is most often used as a generic term for any PDF with geospatial functionality. The term has also been used specifically to distinguish a PDF that uses the georegistration encoding introduced by Adobe in 2008 with Acrobat 9.0 (see PDF_1_7_geospatial) and incorporated into ISO 32000-2 (see PDF 2.0) in contrast to a PDF that used the registration encoding first used by TerraGo in the early 2000s and published as Best Practice OGC 08-139 by OGC in 2009. See US Topo Product Standard (version 2, 2019) for an example of this usage. Since TerraGo added support for the registration encoding from ISO 32000 into its software products and encouraged its use in place of its earlier encoding, a GeoPDF may now have either registration encoding. Unfortunately there is no succinct and clear terminology to distinguish between geospatial PDFs with the different georegistration encodings, although that is an important distinction when deciding which software to use and from the perspective of ensuring long-term access. TerraGo software uses OGC and ISO when presenting the georegistration options. See Should I use ISO or OGC? from TerraGo Support.

    PDF Map is a term used by recently by TerraGo to distinguish GeoPDF® from other PDFs with geospatial functionality. See GeoPDF® vs PDF Maps, which states "TerraGo is the only vendor to supply numerous extensions to geospatial PDF while maintaining full compliance with the geospatial PDF standards."

History

The origin of GeoPDF files was at Layton Graphics, Inc. in 1999. The mapping group of Layton Graphics was spun off as TerraGo Technologies in September 2005. By this time, the term GeoPDF was in use for files created by a tool from TerraGo named MAP2PDF. See, for example, a March 25, 2005 press release from Layton Graphics. Application for registration of GeoPDF as a trademark was in June 2005. For more details, see History of GeoPDF: PDF Map Books, LGIView, and LGIDict (May 2009) and Layton Graphics forms TerraGo Technologies (September 2005).

For details on the history of the original georegistration encoding used in GeoPDF files, starting around 2003, and published in 2009 by the Open Geospatial Consortium (OGC) as Best Practice OGC 08-139r, see GeoPDF_OGC. With the release of Acrobat 9.0 in June 2008, Adobe published the specification of ExtensionLevel 3, including the specification for georegistration that has beemn incorporated into ISO 32000.


Format specifications Explanation of format description terms


Useful references

URLs


Last Updated: 05/08/2024