28 February 2020

Spotlight on spatial data quality

Producers, users, academia and software suppliers gathered in Valletta, Malta recently to discuss the latest developments in spatial data quality. 

The 3rd international conference was organised by EuroGeographics and EuroSDR in conjunction with Open Geospatial Consortium (OGC), International Organisation for Standardisation (ISO) Technical Committee (TC) 211 Geographic Information (ISO TC211), and the International Cartographic Association (ICA).

Chair of EuroGeographics Quality Knowledge Exchange Network, Jonathan Holmes provides an overview of the discussions which showed that the field of spatial data quality and quality management is still evolving as it continues to deal with new technologies and methods of data capture.

Technology is driving the geospatial information industry forward at an ever-growing rate with increasing recognition that quality is of paramount importance. High quality data is the calling card of national mapping, land registry and cadastral authorities (NMCAs) who must continue to meet user demands.

As well as embracing new capture and quality assurance methods, we must also meet user expectations that data will be readily available, accurate, trustworthy and free. This presents new challenges for NMCAs who are the official sources of authoritative geospatial information.

Traditional methods of checking quality are now regarded as too expensive and the focus has shifted onto ways of ensuring that quality assurance is built into a method or process from the very beginning of data capture and production. More rapid data collection methods are creating a need for quicker quality control and assurance procedures and the workshop saw examples of the automation of quality tools from around Europe. 

Managing quality when data comes from multiple suppliers is a key challenge. Delegates heard how this is being achieved in the Finnish National Topographical Database with solid schema transformation, comprehensive quality checks and a dynamic process that ensures no invalid features are included. National Land Survey Finland has also developed digital services to advance the harmonisation of spatial data. These use common definitions, solutions and services with data quality  playing a big part.

E-government brings challenges for data quality and a number of speakers, including our sponsor 1Spatial, offered a number of solutions. We also heard examples from Norway where the Digitalisation Agency and Mapping Authority are working together, and France’s knowledge-based collaborative platform. In addition, e-government was cited as a driver for work on a new common method for declaring quality of data in Denmark.

International standards were very much at the forefront of delegates’ minds during our two days in Malta. Research from the University of Jaén found that ISO 19157-1 must be adapted for dealing with BIM data and other data types with the presenters proposing a model that can be applied in different phases of a BIM project. We ended day one with a focus on the upcoming revision of ISO 19157 (the primary standard for measurement of Geospatial Data Quality). The audience were invited to participate in a session on the forthcoming revision and there were many useful comments made that the authors will take away for consideration.

Meeting users’ needs remained a key theme, with delegates acknowledging that this can often pose difficulties in relation to open data which can be downloaded without having any contact with the supplier.

Presenters also tackled how best to promote the value of quality spatial data. Many users know little about how the data is produced so we must find ways to communicate the trust, quality, provenance, and relevance of our content to all potential users – not just those in the professional community. We were very pleased to welcome representatives from two research projects who shared their findings. The first, from University College London, examined the importance of provenance from the perspective of a geospatial decision-maker. The second, from EuroSDR, looked at definitions of authoritative data across Europe. Finding quality data can also be a challenge for users and in the Netherlands is being addressed through a linked data approach.

New methods of measuring and declaring quality always attract great interest and were addressed by several speakers from academia as well as from NMCAs. These were thought-provoking and, from the feedback received, many delegates will be taking these back to their own organisations to see how they can fit in with what they currently do. Presentations included OpenStreetMap data quality analysis by Ohsome; an interesting case study on the thematic accuracy and completeness of topographic maps by the University of Tartu and an evaluation of height models by Leibniz University Hannover, Germany.

Creating data quality models is one of the main topics of interest to the EuroGeographics Quality Knowledge Exchange Network and our presentation not only discussed how it should be implemented but also gave the example of the European twinning project between Belarus, Spain and the Netherlands.

Further case studies were provided by the MapMalta project and the rebuilding the cadastral map of The Netherlands. 3D capture has long been talked about and there are now some examples appearing, notably in Croatia where data in the third dimension is used in cadastral surveying. Addressing the quality issues that arise with this will continue to be an important consideration. 

EuroGeographics Quality Knowledge Exchange’s mission and objectives are to:

  • Establish a network of data quality experts;
  • Support EuroGeographics policy towards European data interoperability;
  • Share knowledge amongst members; and
  • Promote experiences on quality.

The International Workshop on Spatial Data Quality is a key date in our calendar, with previous events held in 2015 and 2017 providing valuable and innovative contributions to the ongoing debate on spatial data quality, and plays a central role in our aim of improving the usability of geospatial data (In conjunction with EuroSDR), identifying what customers need with regards to quality metrics and how best to present this information.

Bringing together the different players in the spatial data quality arena is mutually beneficial. As well as a welcome opportunity to share their expertise, it also provides a great insight into the latest trends to help inform software development, academic research and production processes.

All presentations are available here.