WalkLite in Mobile GIS: A Schema to Extend and Symbolize SpatiaLite Dr. X. Chen Walkinfo Tech. Co. Ltd.

Background WalkGIS A GIS platform as of 1998 Complying with OGC standards Representing vector and raster geospatial data by Walk schema Providing a C++-like script language for customization A family of GIS products: WalkSurvey, WalkISurvey, WalkIOffice, WalkFloor, WalkCheck, WalkFU, etc. Originally designed for land survey in China, now widely used in land use investigation & planning, house property, transportation, population, etc. WalkGIS A GIS platform as of 1998 Complying with OGC standards Representing vector and raster geospatial data by Walk schema Providing a C++-like script language for customization A family of GIS products: WalkSurvey, WalkISurvey, WalkIOffice, WalkFloor, WalkCheck, WalkFU, etc. Originally designed for land survey in China, now widely used in land use investigation & planning, house property, transportation, population, etc.

Problems in 2013 Traditional desktop-based system is somehow outdated No application can be run on mobile devices End users limited in specific areas Difficulties encountered when translating various geospatial data

WalkGIS Migration 1998 ~ ~ PlatformWindows onlyWindows, Linux, Android DeviceDesktopDesktop, Mobile Base libraryWalk Library Walk Library + GDAL/OGR Graphical UIGDI+GDI+, Skia Built-in data formats Walk MDB, SQL Server Spatial Walk SQLite (WalkLite), Walk MDB, etc. Vector data supported Shapefile, AutoCAD dxf, Mapinfo Data formats supported by GDAL/OGR From Windows to Cross-Platform

WalkLite Walk schema applied in SQLite/SpatiaLite: Adapting OGR SQLite driver Defining four meta-data tables: WalkLayers, SymbolFactory, MetaData, and MetaDataDef. Each WalkLite layer corresponding to three tables:  Features  Symbols  Annotations (text annotations, raster and vector tiles)

WalkLite Layer WalkLite features: OGR SQLite layer containing OGC SRS geometry OGC Feature ID and Walk Feature ID Createtime: Time of the feature creation Style ID: Symbol ID for feature style Feature attributes SpatiaLite is used for spatial index

WalkLite: Annotations WalkLite annotations: OGR SQLite layer containing OGC SRS geometry Points for the location of text annotations Polygons for the location of tiles OGC Feature ID and Walk Annotation ID Annotation: Text that stores the content of annotation or the file path of tile (Format supported by GDAL) Style ID: Symbol ID for annotation style SpatiaLite is used for spatial index

WalkLite: Symbols WalkLite symbols: regular SQLite table Styles ID referred by the features and annotations Style: BLOB data serializing the symbol style Style name and note

Advantages of WalkLite Cross-platform: No data translation required between mobile application (data collection) and desktop application (data processing) One schema for both vector and raster data, also map styling Comparatively fast by using SpatiaLite index

WalkLite-based mobile GIS App used in a number of Chinese provinces for: Land investigation Land use Planning Cadastral inventory Real estate analysis … WalkLite Applications

Cross-platform SDK Supporting iOS WalkLite driver in GDAL/OGR [ODBC-based Walk driver already in GDAL/OGR (version >=1.10.0)] Further improving and optimizing the performance of WalkLite data Cross-platform SDK Supporting iOS WalkLite driver in GDAL/OGR [ODBC-based Walk driver already in GDAL/OGR (version >=1.10.0)] Further improving and optimizing the performance of WalkLite data Future Work?

Questions?