Data Files Concept
GeoBase File System (GBFS) files are geospatial database files used by GeoBase to support a number of operations, including mapping, geocoding, routing and navigation. These files are identified by a .gbfs extension. GeoBase applications can automatically load data files from default locations, or you can use the classes and methods in the Telogis.GeoBase.Repositories namespace to load these manually.
There are a number of different types of GBFS file available, providing support for different GeoBase features.
This category of data files contain all the information required for mapping, geocoding, routing and navigation. Data for a country is usually distributed as a single GBFS, but larger countries may be split into regions and distributed as multiple files.
Basemap Data - the standard GeoBase map data file. Contains speed limit information for Functional Class 1 & 2 roads. Is optimized for use with the drilldown geocoder and the autocomplete geocoder. Note: If you are using data files from 17Q3 (2017, 3rd quarter), with an L in the suffix of the file, you must use GeoBase version 4.31 or later to be able to use the Drill-down Geocoder or the Autocomplete Geocoder.
Premium Speed Data - an enhanced version of the basemap data intended for use in applications where speed limit information is of core importance. This data extends the coverage of speed limit information to include Functional Class 3 & 4 roads.
When routing between two map data files (either between countries or between regions for countries split into multiple files), it is important that the map data files for these countries are from the same provider and the same release quarter. For example, HERE Bulgaria 12Q2 can safely be used with HERE Greece 12Q2, but not with TomTom Greece 12Q2 (different provider) or HERE Greece 12Q3 (different release quarter).
This recommendation is in place as slight differences in road digitisation between data providers, or changes in road layouts between release quarters, can cause cross-border roads to fail to align correctly, which may result in routing failing or the generation of non-optimal routes.
These files are designed to be used alongside basemap data to add support for advanced GeoBase features. They cannot be used as standalone files for mapping, geocoding or routing.
Truck Attribute Data - contains details of road constraints that should be considered when routing with specific types of vehicle, such as height limits for tunnels, weight limits for bridges or restrictions on cargo types (for example HazMat). For further information on truck constraint routing, see Using Truck Attributes.
Point Address Data - contains geospatial points which correspond to numbered addresses, allowing enhanced geocoding accuracy and the rendering of address numbers on the map. For further information, see Address Interpolation and Point Address Data.
ADAS Data - contains information about gradient changes along streets, which can be used as part of advanced custom routing systems. For further info on using ADAS, see Routing with ADAS Data.
|It is important that supplementary data files are used with map data files from the same provider and release quarter. For example, HERE France Truck 13Q3 should be used with HERE France 13Q3 map data, not with TomTom France 13Q3 (wrong provider) or HERE France 13Q2 (wrong release quarter). When using the wrong map data, the keys used to link the properties in the supplementary data to the correct streets in the map data may be incorrect, resulting in properties being absent or incorrectly applied.|
Global Data files contain land polygons, national borders and city points for the entire world, and are designed to be used alongside basemap data to improve cosmetic appearance. They contain no road network information, and cannot be used for geocoding or mapping.
|Global Data can either be used as a standalone file in a MultiRepository, or optionally be embedded into another GBFS file using GBFS Tool, a utility program that ships with the GeoBase SDK.|
The Alchemy Data Import Tool can be used to build GBFS files containing custom data. This may be as simple as a non-spatial table, or as complex as a production grade map data file for an entire country. This data typically comes from a Shapefile source, but CSV files and WKT strings can also be used. For further information on creating custom data, see Alchemy Data Import Tool.
When updating map data for GeoBase versions 4.4.x or earlier, downloaded GBFS map data files must be decompressed using a compression utility. This process is not required for GeoBase versions 4.5 or later.
When deploying an application it is often undesirable to place data files in a fixed location. GeoBase allows for this by automatically searching a number of locations for data files.
A Repository object may be used to manage data files, and provide access to specific data files on a per-thread basis.
GeoBase data is distributed by region. A region is often a single country, but large countries (such as the United States) are often split into a number of smaller regions.