German NRW Elevation Model

Elevation model 1m grid. Part of wind farm near Linnich, NRW. Color legend uses a 2.5m equidistance.

Elevation model 5m grid. 44 wind turbines near Linnich, NRW.

Introduction

The elevation model of the German Bundesland of Nordrhein-Westfalen (NRW; North Rhine-Westphalia) is a digital terrain model produced from data originally obtained from Geobasis NRW. The derived elevation model delivered with windPRO is at 5m resolution. The original model at 1m resolution is named DGM1 (Digitales Geländemodell 1m / Digital Elevation Model 1m). However, the windPRO version is resampled by EMD to obtain a slightly coarser resolution - 5m - in order for the data to be operational for the larger areas needed in the context of wind farm analysis’. The laser-scans in the DGM1 model were obtained with a sampling rate of 1-4 points per square meter. A continuous LIDAR measurement campaign is being made, with the whole of the state being completed at a 6-year cycle. The data made available by EMD represents the data status of January 2019.

Dataset Overview

• Spatial Coverage: NRW, Germany
• Resolution: 5m (in windPRO)
• Data-type: Digital Terrain Model (DTM)
• Coordinate system
  • Horizontal: ETRS89/UTM33 (EPSG 25833)
  • Vertical: Staatliches Nivellementnetz 1976 (EPSG 5181)
• Version:
  • Data were downloaded in February 2020.
  • Data originates from aerial scans mainly from years 2010-2019. Elevations were obtained by laser-scans (LiDAR) and by photogrammetry. See this pdf.
• Accuracy:
  • Vertical: 0.3m (in original 1m data)
  • Horizontal: 0.3m (in original 1m data)

Acurracy

Vertical accuracy in the 1m resolution dataset is stated to be ±0.2m, however will be larger in areas with forest, industry, at settlements or steep-slopes. The acurracy of th 5m model delivered with windPRO was evaluated on 44 turbines near Linnich - taking the 1m model as reference data (ground truth). At the turbine positions, deviation from the 1m model was an average of -0.02m and the standard deviation was 0.09m. A comparison with other DTM/DSM's are shown in the table below.

44 wind turbines at Linnich - evaluation of DGM accuracy by evaluating the deviation (in meters) from NRW-DGM1.

Parameter	NRW-5m	DGM-200m	SRTM-1	SRTM-3	EU-DEM
Mean	-0.02	-0.56	-1.55	-1.63	-1.35
Standard Deviation	0.09	0.90	1.29	1.11	1.09
RMSE	0.10	1.06	2.02	1.97	1.73
Minimum	-0.40	-2.70	-4.60	-4.00	-3.60
Maximum	0.20	1.70	1.90	2.30	2.30

Availability from within WindPRO

The data are available directly from within windPRO in 5-meter grid resolution. Please note that the downloaded area is limited to 10 km x 10 km to keep the files at a usable size. The data within the elevation object may be extended with coarser data fo a bigger area if needed. The data can be accessed from the online-services in the following objects:

• Line Object (with purpose to height contour lines)
• Elevation Grid Object

Reference System

The following reference system were used in the original data:

• ETRS89/UTM32 (EPSG 25832)
• Vertical: DHHN2016 (EPSG 7837)

License and Attribution

The product belongs to the open geo-data of Nordrhein-Westfalen. The data have been licensed under a Data license Germany – attribution – version 2.0 (Datenlizenz Deutschland - Namensnennung - Version 2.0) -"dl-de/by-2-0".
Please accept the license conditions and use a proper attribution when using this dataset, such as:

Contains modified elevation data from Geobasis NRW (geobasis.nrw.de). Adapted and distributed by EMD and windPRO. “dl-de/by-2-0".

Acknowledgement

• The Geobasis NRW are thanked for producing this digital elevation dataset – and disseminating it in the public domain and thus for aiding the development of renewable energy.
• Integration of this dataset into EMD services was co-supported through the InnoWind project ([http://www.innowind.dk www.innowind.dk) which is co-funded by the Danish Innovation Fund

External Links

1. Site with description of the elevation model (in German language): http://www.geobasis.nrw.de
2. InnoWind project: http://www.innowind.dk