1. USING NATIONAL DIGITAL ELEVATION MODELS FOR CROSSBOUNDARY APPLICATIONS: A QUALITY ASSESSMENT.
- Author
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Stal, Cornelis, Verbeurgt, Jeffrey, De Sloover, Lars, Deruyter, Greet, and De Wulf, Alain
- Subjects
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DIGITAL elevation models , *ELECTRON tube grids , *COORDINATE transformations , *GEOGRAPHIC spatial analysis , *COORDINATES , *STANDARDS , *SPACE-based radar - Abstract
Digital elevation models play a crucial role in the analysis of complex spatial challenges. Given the international dimension of many environmental applications, elevation data have been integrated in the European INSPIRE directive (Annex II, Elevation theme). As a result, many types of data are offered in various formats by mapping agencies and governmental organizations within the European Union. Notwithstanding the national effort to publish these data under open and public licenses, and in compliance with international data standards, the models are often projected in national coordinate reference systems, containing local orthometric heights. In order to use these models for cross-boundary applications, a transformation of locally projected coordinates and local elevations to international coordinates and ellipsoidal heights is required. Planimetric coordinate transformations are regularly performed using analytical conversion models, whereas altimetric transformations make use of geoidal models or simple vertical shifts. In this paper, digital elevation models from the Netherlands and the Flemish Region (Belgium) are transformed using the corresponding geoidal transformation grids and a simple vertical shift. Both data sets are independently acquired and processed within the framework of governmental mapping campaigns. The projected Dutch RD coordinates (EPSG:28992) and Belgian Lambert ’72 coordinates (EPGS:31370) are converted to ellipsoidal WGS84 coordinates (EPGS:4326) using open-source OGR tools. In order to obtain ellipsoidal heights from the elevation models, NLGEO08 and hBG18 are used for the conversion of Dutch and Belgian elevations respectively. Based on a quality assessment of both data sets in overlapping areas, it is stated that the mean difference and standard deviation of the elevations are within the accuracy levels of the used elevation models (0.07 ± 0.16 m). [ABSTRACT FROM AUTHOR]
- Published
- 2019
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