As part of its involvement with the Open Data Institute’s geospatial stimulus programme, Bath and North East Somerset Council has been reviewing how it creates and publishes mapping data. This post looks at the methods of publication and how they are changing.
Geospatial data (maps) are released by the council for a range of purposes:
- As open data, for reuse for any purpose, or restricted use such as non-commercial activities
- To publish statutory information, such as planning applications
- To support marketing activities, such as advertising new developments, walking routes, or proposed schemes
- To enable consultants to undertake work in behalf of the Council.
- To help other agencies target services
How data is currently released:
The method by which the Council currently releases geospatial data is mixed and heavily reliant on ad-hoc releases.
- DistrictOnline is the main route of publication and sharing of data, however this use is primarily internal, as information shared is linked to and derived from Ordnance survey copyrighted data. This system also publishes the Council’s INSPIRE datasets to data.gov.uk
- The Ishare system is used as the main method of publishing data to the public via it’s own web front end, webmap service (wms) to cloud systems such as Fix my Street as well as publishing non-spatial data via csv to Bath:Hacked (parking, electricity/gas).
- E-mail Ad-hoc releases of data, to the public, on request from Councillors, to consultants are also made via e-mail. Data released in this manner is ungoverned and undocumented. These ad-hoc releases form the basis of Council data currently held in the Bath:Hacked geospatial github repository. This route was developed as the existing Bath:Hacked datastore does not effectively hold geospatial data other than where longitude/latitude points are defined.
- CD In addition, the archives service offers the commercial release of certain historical GIS data through CD.
Future release mechanisms
It will never be possible, nor desirable to restrict all ad-hoc transfers of geospatial data, which is common to many hundreds of processes within local government, a clear opportunity to improve the release of standardised data
By replacing proprietary technical systems with open source alternatives, the Council will be able to manage the release of open data alongside the update of the underlying data in the corporate GIS server.
By deploying as PostGres database as the core, corporate GIS server, it is possible to use open source tools (Ogr2Ogr, in this case) to manage both the internal onward use, and future publication of the system.
Inspired by the Bath Hacked geographic data repository, the Council will shortly launch a github repository where this data can be accessed and which will then update in line with the main server. This means that the Council can schedule periodic (to be defined against the frequency of update of the dataset).
Formats
As the Council uses Ordnance Survey geographies for the overwhelming majority of its geospatial work, much of its data comes associated with Eastings and Northings, rather than the longitude and latitude fields required by many platforms. The Council will be experimenting with Ogr2Ogr to automate the conversion of its files to these coordinate systems.
The Council also needs to learn the most appropriate format/s to release our data, with different users requiring different formats for their purposes. To date, the following have been identified as popular formats for open release.
- Full database copies, for advanced users, who are looking to all the geospatial files published
- .shp files although being traditionally linked to the ESRI mapping systems, .shp files remain a common industry standard, particularly for people looking to access and manipulate data using the QGIS system.
- .geojson files An open standard geographical format designed for rendering lines and points, increasingly used for web based visualisation and applications.
- .csv files A standard ‘flat’ data format, that is not effective for storing geospatial data unless locations are expressed as simply points (through co-ordinate fields).
In addition there is an opportunity to link to work being undertaken by Ordnance Survey around future formatting, but a locks government approach needs to balance the needs of both people who are familiar with GIS tools and more general users who want to use data though more generic tools, such as through the web.
How can you get involved?
Over the next month the Council is looking to start releasing data through its new publication route. However, this data will only be as useful as its practical applications, so we need the community to be part of its development, in particular
- Helping us to understand the best metadata to release alongside
- Joining in the discussion about appropriate formats.
- Once it is published, using the data to do interesting things!