Improving Cross-border Data Reliability Through Edge-matching
ISBN 978-85-88783-11-9
Authors
1Lee, D.; 2Yang, W.; 3Nobbir, A.
1ESRI Email: dlee@esri.com
2ESRI Email: wyang@esri.com
3ESRI Email: nahmed@esri.com
Abstract
Improving Cross-border Data Reliability Through Edge-matching Dan Lee, Weiping Yang, Nobbir Ahmed Esri Inc., 380 New York Street, Redlands, CA, USA Abstract. The demands on consistent geospatial data for cross-border analysis and mapping are growing at local, national, and global levels. Many national mapping agencies and GIS organizations are facing challenges in keeping data harmonized across internal and external boundaries. Discrep-ancies and misalignments among neighboring datasets must be resolved to ensure seamless coverage. These tasks are critical to making data reliable for use within agencies and organizations and for collaborative work across their borders. For example, in order to compile state roads from county roads, all county roads must properly meet neighboring county roads at their borders. Misaligned or disjoined roads would cause errors in routing and other spatial analysis and result in poor quality mapping. Edge-matching is the process of matching correspondent features along borders (or edges) and making spatial adjustments such that they connect and extend through the borders without spatial conflicts or errors. Edge-matching may be needed between map sheets or across any natural or manmade boundaries. This paper examines some typical edge matching issues with the focus on liner features, presents the edge-matching tools in ArcGIS Desktop developed by Esri, and discusses the workflows that help improve cross-border data quality. Depending on data quality and complexity on both sides of borders, matching correspondent features automatically can be challenging. The more congested the features are, the higher the ambiguity. For linear features, edge-matching is mostly based on proximity, topology, and continuity anal-ysis, as well as optional attributes. Once matched features are determined, edge-match links are generated from features in one dataset to matched features in the adjacent datasets. Due to the possibility of making incorrect matches, an evaluation process is necessary to flag potential issues with the generated links, followed by interactive review and editing if issues are found. The confirmed and improved edge-match links can then be used to guide the spatial adjustment to connect features. The two edge-matching tools, Generate Edgematch Links and Edgematch Features, available since ArcGIS Desktop 10.2.1, can be used to automatically edge-match features and generate links and to perform edge-match spatial adjustment respectively. Additional geoprocessing workflow tools have been built to evaluate the edge-match links and to facilitate post-processing. Two use cases have been studied and tested. The first use case requires edge matching between roads maintained by the Resource Management Service, LLC (RMS) and the commercially available TIGER roads outside RMS boundaries. Initial test results and quality assessments will be presented. The second use case is the expected edge matching tasks along borders of participating countries of the European Location Framework (ELF) project. Since test data are limited, a few observations and thoughts will be presented. Using the workflow described above, high accuracy of edge-matching can be reached through automated processes and minimal interactive work. Cross-border data quality and reliability can be significantly improved. Future enhancements will also be discussed.
Keywords
edge matching; cross-border; data quality and reliability