#GeoPackageDay 2020 - what is GeoPackage?
Geospatial information is a key enabler of effective decision-making. The Open Geospatial Consortium (OGC) is committed to enabling technologies that make geospatial information available where and when it is needed. Part of that strategy is in the development of the GeoPackage Encoding Standard. On this #GeoPackageDay, we celebrate the 6th Anniversary of the first publication of this standard.
In addition to interoperability (one of OGC’s core values), GeoPackage was devised with three main goals in mind: the first goal is to be a convenient, efficient container for geospatial information; the second goal is to enable operations in all computing environments, including those with Disconnected, Degraded, Intermittent, or Limited (DDIL) network connectivity. Allow me to discuss how GeoPackage meets the first two goals before moving on to the third.
GeoPackage can store multiple datasets, datatypes, and metadata records in the same file, minimizing cumbersome and inefficient file manipulation. By building on the industry-standard SQLite relational database, GeoPackage enables rapid reading and writing operations. Since nearly every operating system today supports SQLite, GeoPackages can be used on virtually any device on the planet - from Cloud infrastructure to a smartphone. Software can access GeoPackages residing in local device storage instead of relying on networks that may not always be available. In addition, network use reduces battery life - and sometimes that really matters!
Figure 1: Multiple layers in a GeoPackage
We are continuing to see an increase in GeoPackage's use as a distribution format all over the world. Organizations like OpenStreetMap, British Geological Survey, and Swedish National Land Survey are seeing the benefits and migrating to GeoPackage. If your organization distributes geospatial data, are you distributing it as GeoPackage? If not, info [at] ogc.org (get in touch) and let us know what's preventing you from using it. Maybe you can help us fix something!
Meanwhile, software developers are exploring ways to leverage GeoPackage’s capabilities to improve operational efficiency, particularly in an off-line setting. These capabilities have a role in a wide variety of domains, including military, emergency response, and land use. Three common uses are visualization of a common operational picture, data collection, and analysis operations such as filtering and routing. These capabilities require an infrastructure that can produce a GeoPackage containing the specific information required, provision the GeoPackage to the devices that will use it, and incorporate the collected data into enterprise data repositories.
Figure 2: GeoPackage enabling operations across multiple domains
The third goal is for GeoPackage to be extensible, allowing it to evolve to meet future operational needs. The GeoPackage standard has a built-in extension mechanism that allows a particular GeoPackage file to declare what extensions are in use. This allows software to make the best possible use of the available information based on what capabilities it supports.
When GeoPackage was first published in 2014, it supported two data types - features and raster tiles - and extensions such as metadata, schemas, and spatial indexes. In addition to regular maintenance to improve clarity and consistency in the standard, the GeoPackage Standards Working Group (SWG), of which I am a Chair, is actively promoting the development of new extensions that address a clear operational need, have a sound technical approach, and have a commitment to implementation by the software development community. OGC has since adopted core support for attributes and extensions for tiled gridded coverages and related tables. Other extensions are in various stages of development, standardization, and adoption.
OGC is continuing to push GeoPackage capabilities forward through its Innovation Program. The recently completed Open Portrayal Framework thread of Testbed-15 explored ways to store portrayal information (styles and symbols) along with feature and/or coverage data in a GeoPackage. One of the objectives of the Vector Tiles Pilot Phase 2 is to leverage GeoPackage and vector tiles to deliver feature data more efficiently in both on-line and off-line scenarios. In the upcoming Testbed-16, participants will advance the discoverability of the contents of a GeoPackage through metadata profiles and improve the efficiency of using large scale vector datasets in GeoPackage. Figure 3 illustrates how GeoPackage can participate in an end-to-end geospatial architecture supporting on-line/off-line as a result of these advances.
For more on GeoPackage, see geopackage.org.
Figure 3: GeoPackage as part of an end-to-end geospatial architecture
Jeff Yutzler is a Senior Engineer at Image Matters LLC, a software technology and professional services firm providing enterprise-grade solutions for demanding industries. He has 25 years of software and systems engineering experience and has specialized in geospatial technology solutions since 2000. He has been working with OGC since 2002 and has served as a GeoPackage SWG Chair since 2014.