® OGC GeoPackage Encoding Standard Paul Daisey GeoPackage SWG Chair, Editor July 22nd 2014 MITEmeeting
Problem – Why GeoPackage? • Effective, large-scale collaboration in military, homeland security, and disaster management relies upon the sharing of geospatial information. • However, this is significantly constrained under conditions of limited or non-existent bandwidth or power. • An explosion of map applications for mobile handheld devices has resulted in a variety of incompatible dataformats and interfaces. • No existing standardaddresses the provisioning of all types of geospatial data on traditional computing platforms or assorted makes of mobile handheld devices.
Geopackage: Raster Maps, Images and Feature Data in One File Imagery Low – High Resolution Feature Data Raster Maps: Small – Large Scale Tile Pyramids 22 zoom levels Single File Sqlite Database containing all data for direct-use on mobile platforms & handheld devices
GeoPackage Inception • Concept initiated by scientists and engineers from AGC/TEC and NGA at a hosted TEM with open source and commercial software developers • Initial start as Google Groups Discussions • OGC Web Services Phase 9 (OWS-9) • Developed initial draft spec and prototype applications • Brought initial work and google group members to OGC because of need for stds development structure and potential IPR concerns. • GeoPackage SWG Established October 2012 • 14 Voting Members, 65 Non-voting Members and Observers • SWG Portal and SWG WIKI documenting • Teleconferences, Discussion Items, Change Requests
GeoPackage Evolution (1) • OGC Web Services Phase 9 (OWS-9) (2013) • Informal Public Review of Draft Spec January 2013 • SWG Resolved 59 Issues (Public Comments) & 74 Issues (SWG Members) • Three Initial Implementations (Luciad, OpenGeo, AGC R&D) • OGC RFC formal Public Review of Draft Spec August 2013 • SWG Resolved 19 Issues (Public Comments) & 12 Issues from SWG Members • OGC Web Services Phase 10 (OWS-10) (current) • Open Mobility Thread • GeoPackaging Service Reference Implementation • GeoPackage Synchronization with WMS, WFS, WMTS • Mobile GeoPackage and OWS Context Client App • OGC TC and PC vote (Approved Feb 2014) • Published as traditional .pdf document http://www.geopackage.org/ -and- http://www.opengeospatial.org/standards/geopackage • Also, available online in GitHub repository for software developers https://github.com/opengis/geopackage
GeoPackage Evolution (2) • GeoPackage SWG Charter Revision • SWG Deliverables • One corrigendum revision of the GeoPackage Encoding Standard • GeoPackage Implementation Guide Best Practices Document • OWS Context Document Guide for GeoPackage Best Practices Document • CRPs for the GeoPackage and other OGC Standards • CITE TEAM Engine TestNG ETS for the GeoPackage Encoding Standard and its SQLite Configuration and SQLite Extension • One or more revisions of the GeoPackage Encoding Standard • Approved by SWG 2014-06-24 • OGC TC Review period ended 2014-07-15
U.S. DoD / IC GeoPackage Activities • R&D Organizations using GeoPackage in Apps • AGC ERDC • NGA Mobile Apps • DARPA TransApps • NSG Adopts OGC Standard • Review w/in NSG GWG (Standards GeoINT Working Group) • Vote Summer 2014 • Submit as DISR Standard 14-2 • DOD/IC Profile of Geopackage Spec. • AGC • NGA • DISA • DARPA • Additional Capabilities in Future Version(s)
GeoPackage Potential Future Work • GeoPackage potential extensions • Elevation Data (lots of interest expressed) • Routes (initiated requirements/use-case work but much to do.) • Data Import / Export Utilities • Geographic / Geodesic geometry types • Additional Image MIME types (e.g. JPEG2000) • Abstract Object Model and Non-SQL Encoding • Symbology and Styling • UTFGrid support • Other Standards & potential extensions (e.g. OWS-10) • GeoPackaging OGC Web Service • Other OGC Web Services use GeoPackages for input / output, synchronization, perhaps using OGC Context document descriptors
DoD / IC GPKG Profile Draft Issues • Tiles • Additional Bounding Boxes for Tiles • Tile Sizes / Zoom Level Well Known Scale Sets • Tiles and Features • Metadata (Need SME input!) • Specified Spatial Reference Systems (SRS) and Well Known Text (WKT) Definitions • Features • Coordinate Transformation Functions SQLite Extension • SQL-MM Geometry Functions SQLite Extension • NAS/GGDM Features Schema –> SQL Table Definitions • Standard Registered Extensions - Required instead of Optional • Data Integrity Validation Tests / Additional Triggers • Data Column Constraints • Specify Profile as GeoPackage Extensions
GPKG Additional Tile Pyramid Bounding Boxes • GPKG has per-table bounding boxes • This extension adds an nsg_tile_matrix_extent table to contain additional bounding boxes specifying more detailed rectangular extents of tile image availability • Provide bounding boxes for every tile in a fully populated or sparse tile pyramid as a pre-computed cache of tile extent information as a space/time trade-off to avoid repeatedly computing individual tile bounds from the gpkg_tile_matrix_set table minimum bounding box and tile size, zoom level, and row and column position. • Provide bounding boxes that indicate where complete tiles of tile image data are available in a sparse tile pyramid. • Provide bounding boxes that indicate where tiles are missing in a sparse tile pyramid. • Provide bounding boxes that indicate rectangular extents of the presence of tile image data in one or more tiles. • Provide bounding boxes that indicate rectangular extents of the absence of tile image data in one or more tiles • Provide bounding boxes that indicate rectangular extents of mixed areas where tile image data is both present and absent in non-rectangular patterns.
GPKG Tile Sizes / Zoom Level Well Known Scale Sets (1) • Only specified tile sizes? • 256 x 256? Commercial practice, NettWarrior • 512 x 512? Naval Research Lab Ghub • Rectangular for Polar Regions in UPS? • Standardize zoom levels / pixel sizes? (following slides) • Only times two zoom levels? • Also zoom other intervals? • Current Draft: 256 x 256 times two zoom
GPKG Tile Sizes / Zoom Level Well Known Scale Sets (2) • General well known scale sets (from OGC WMTS) • GlobalCRS84Scale • for vector cartographic products • pixel size in degrees • zoom other intervals • GlobalCRS84Pixel • for raster cartographic products • pixel sizes in meters • zoom other intervals • some zoom levels pixel sizes match STRM (1" and 3"), GTOPO (30") or ETOPO (2' and 5'). • GoogleCRS84Quad * • for earth images • pixel sizes in degrees • zoom times 2 • tiles of 256x256 pixels • GoogleMapsCompatible(Microsoft Live Compatible) * • for rasterized maps • pixel sizes in meters • zoom times 2 • tiles of 256x256 pixels * GPKG WKSS alignment
GPKG Tile Sizes / Zoom Level Well Known Scale Sets (3) * Universal Transverse Mercator (UTM) and Universal Polar Stereographic (UPS) TBD * scale denominator and pixel size values are only accurate near the equator.
GPKG Tile Sizes / Zoom Level Well Known Scale Sets (4) • For existing DoD products
GPKG Spatial Reference Systems • Geographic 3D • WGS 84 lat/lon/hae (HRE ¹) • Geographic 2D • WGS84 lat/lon • Projected Horizontal • World Mercator ² • Universal Transverse Mercator (UTM) • Universal Polar Stereographic (UPS) • Vertical ³ • EGM 2008 geoid height / depth • EGM 1996 geoid height / depth • Mean Sea Level (MSL) height / depth • Compound • Geo 2D / Projected + Vertical combinations ¹ NGA.IP.0002_1.0(HRE) ² NOT Spherical (Web) Mercator per NGA.SIG.0011_1.0.0_WEBMERC ³ http://earth-info.nga.mil/GandG/publications/vertdatum.html
Features • Coordinate Transformation Functions SQLite Extension • SQL-MM Geometry Functions SQLite Extension • NAS/GGDM Features Schema –> SQL Table Definitions • Standard Registered Extensions - Required instead of Optional • Data Integrity Validation Tests / Additional Triggers • Data Column Constraints
GPKG Coordinate Conversion and Transformation Functions - Optional SQLite Extension • SQL function signature derived from ISO SQL/MMST_Transform method * • ST_Transform(geom StandardGeoPackageBinary, toSrid INTEGER) (required) • ST_Transform(geom ExtendedGeoPackageBinary, toSrid INTEGER) (conditional) • (required if ExtendedGeoPackageBinary registered extension implemented) • Any Implementation Code / Library that uses parameter values from gpkg_spatial_ref_sys table definition column • NGA GEOTRANS * GOTS Extension • PROJ.4 Open Source • Other Commercial or Open Source • GEOTRANS * results are the reference implementation • Abstract Test Suite (ATS) reference data to be derived from GEOTRANS and NGA Gold Data * ISO/IEC 13249-3 * http://earth-info.nga.mil/GandG/geotrans/#zza3 * http://earth-info.nga.mil/GandG/coordsys/Conversion_Software/index.html
Contacts • Paul Daisey SWG Chair, Editor 301-651-7148 email@example.com • Jeff Harrison SWG Co-Chair 703-628-8655 firstname.lastname@example.org • Kevin Backe 703-428-6505 Kevin.Backe@usace.army.mil