Pseudo station data of gridded hourly near-realtime data of surface irradiance and sunshine duration based on surface measurements and satellite observations - DUETT Project

Based on the DUETT gridded data, additional point data is determined at the coordinates of 576 measurement sites of DWD. These pseudo station data are extracted from the gridded data using a simple ‘nearest neighbour’ assignment and are optimized by a subsequent topography correction. This correction is performed using high-resolution topographic data and it primarily captures the possible blocking of direct solar radiation by surrounding mountains. Associated uncertainties are also determined from the gridded data using a ‘nearest neighbour’ assignment and are not subject to any further adjustment in the current program version.


The data set is separated into two parts: the directory ./{parameter}/recent/ contains the latest data; in the directory ./{parameter}/historical/ older data are archived.

Simple

Alternate title

urn:x-wmo:md:de.dwd.cdc::derived_germany-climate-hourly-duett
Date (Publication)
2024-01-01
Date (Revision)
2024-01-01
Edition

006
Edition date
2024
Citation identifier
urn:x-wmo:md:de.dwd.cdc::derived_germany-climate-hourly-duett

CDC2.1:WMO-URN CDC2.1:WMO-URN 2024

Presentation form
Digital table
Status
On going
Point of contact
  Deutscher Wetterdienst - CDC - Vertrieb Klima und Umwelt
Frankfurter Strasse 135 , Offenbach , Hessen , 63067 , Deutschland
+ 49 (0) 69 8062-4400
+ 49 (0) 69 8062-4499
https://dwd.de
Hours of service

09:00 - 16:00
Maintenance and update frequency
Continual
Update scope
Dataset
Maintenance note

In the directories ./{parameter}//recent/ the data files are updated hourly.
Owner
  Deutscher Wetterdienst - Satellitengestütztes Klimamonitoring - DUETT ( )
Frankfurter Strasse 135 , Offenbach , Hessen , 63067 , Deutschland
+49 (0) 69 8062-0
+49 (0) 69 8062-4499
https://dwd.de
Hours of service

10:00 - 15:00
Maintenance and update frequency
Annually
Maintenance note

In the directories ./{parameter}/historical/ the data files are updated annually.

The hourly data files are merged into monthly files.
Owner
  Deutscher Wetterdienst - Satellitengestütztes Klimamonitoring - DUETT ( )
Frankfurter Strasse 135 , Offenbach , Hessen , 63067 , Deutschland
+49 (0) 69 8062-0
+49 (0) 69 8062-4499
https://dwd.de
Hours of service

10:00 - 15:00
Point of contact
  Deutscher Wetterdienst - Climate Data Center (CDC) - Betrieb
Frankfurter Strasse 135 , Offenbach , Hessen , 63067 , Deutschland
+ 49 (0) 69 8062-4400
https://dwd.de
Hours of service

09:00 - 16:00

GEMET - INSPIRE themes, version 1.0

  • Meteorologisch-geografische Kennwerte

  • Atmosphärische Bedingungen

DWD Climate Data Center Vocabulary - Geographische Region

  • Germany
DWD Climate Data Center Vocabulary - Datenherkunft

DWD Climate Data Center Vocabulary - Zeitliche Auflösung

  • hourly

Climate and Forecast Standard Names

  • surface_downwelling_shortwave_flux

  • duration_of_sunshine

DWD Climate Data Center Vocabulary - Parameterklasse

  • radiation and sunshine duration
Keywords

  • opendata

DWD Climate Data Center Vocabulary - Parameter

  • sunshine duration

  • global radiation
High-value dataset categories

DWD Climate Data Center Vocabulary - Einheit

  • J/cm²

  • minutes
Specific usage

The data represent the value at the specified coordinate, based on the nearest neighbor grid value and topographic shading. The specified MESS_DATUM describes the end of the synoptic hour for which the data apply. The synoptic hour HH:00 denotes the hour from (HH-2):50 to (HH-1):50.
User determined limitations
considerations
Specific usage

The main focus of these products is on the provision of near real-time observations. The software for generating the gridded data (source data for pseudo station data) is constantly being improved and updated, which can lead to discontinuities when analysing long time series. In the case of heterogeneous cloud conditions, especially in mountainous regions, the gridded data may differ, sometimes significantly, from the measurements of nearby stations. This is due to the different spatial representativeness of the two measurement methods. Small-scale features such as cumulus clouds or fog patches may not be represented in the gridded data. Further sources of error are geometric errors, which are caused by different positions of the satellite and the sun relative to the observation point. With clear sky and snow cover, there is a potential for a considerable underestimation of solar irradiance and sunshine duration in the gridded data. Since the introduction of version 007 of DUETT (19 Nov 2024), these snow-related errors have been at least partially rectified by using independent cloud mask data as an additional source of information.
User determined limitations
uncertainties
Access constraints
Other restrictions
Other constraints
no Limitations
Use constraints
Other restrictions
Other constraints
{"id": "cc-by/4.0","name": "Creative Commons Attribution – 4.0 International (CC BY 4.0)","url": "http://creativecommons.org/licenses/by/4.0/","source": "Source: [Deutscher Wetterdienst](https://www.dwd.de/copyright)"}
Other constraints
The Creative Commons BY 4.0 - Licence "CC BY 4.0" apply.

Resource constraints

No information provided.
Spatial representation type
Text, table
Language
Deutsch
Topic category
  • Climatology, meteorology, atmosphere
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Geographic identifier
stations in Germany
Begin date
2024-01-01
Supplemental Information

The underlying gridded data are obtained from ground measurements and satellite data using a geo-statistical method. This method and the method for deriving point data is subject to continuous further development; a temporal homogeneity of the data cannot be guaranteed. Changes in the method used are indicated in the file name. A complete check of the data does not take place; we are grateful for information on problematic data points in the gridded data (see Contact).
Unique resource identifier
EPSG:4326
Topology level
Geometry only
Geometric object type
Point
Geometric object count
576
Distribution format
  • csv ( )

Point of contact
  Deutscher Wetterdienst - CDC - Vertrieb Klima und Umwelt
Frankfurter Strasse 135 , Offenbach , Hessen , 63067 , Deutschland
+ 49 (0) 69 8062-4400
+ 49 (0) 69 8062-4499
https://dwd.de
Hours of service

09:00 - 16:00
OnLine resource
recent hourly mean surface downwelling shortwave radiation (SIS) ( WWW:LINK-1.0-http--download )

The folder .radiation_global/recent/ contains recent hourly pseudo station data files in ASCII format.

OnLine resource
recent hourly sunshine duration (SDU) ( WWW:LINK-1.0-http--download )

The folder .sunshine_duration/recent/ contains hourly pseudo station data of the current year in ASCII format.

OnLine resource
Brinckmann et al., EMS 2022 ( WWW:LINK-1.0-http--link )

Brinckmann, S., Klameth, A., and Trentmann, J.: Combination of satellite and ground measurements of hourly surface solar radiation data in Germany, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022

OnLine resource
Klameth et al., 2022 ( WWW:LINK-1.0-http--link )

Klameth, A., Brinckmann, S., and Trentmann, J.: Towards the combination of in-situ and satellite-based solar radiation data in near-realtime – the project DUETT at DWD, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022

OnLine resource
List of pseudo-stations: global radiation ( WWW:DOWNLOAD-1.0-http--download )

List of pseudo-stations for which global radiation values are derived.

OnLine resource
List of pseudo-stations: sunshine duration ( WWW:DOWNLOAD-1.0-http--download )

Liste der Pseudo- Stationen, für die Werte der Sonnenscheindauer abgeleitet werden.

Hierarchy level
Dataset

Conformance result

Date (Publication)
2010-12-08
Pass
Yes

Conceptual consistency

Name of measure
quality_estimation
Measure description

So-called standard uncertainties are estimated on the basis of the following statistics: (a) standard deviation, based on the so-called ‘kriging variance’ of the interpolated regional bias; (b) spatial standard deviation of hourly GHI / DNI Duett around each grid point (based on 25 adjacent grid points each); (c) spatial offset caused by differences in the observation or irradiation angles of the satellite or the sun (assuming a small-scale cloud with a top height of 5 km). The variables (b) and (c) are linked, as the spatial offset in satellite observation only has an effect if the data field around a station is heterogeneous. For this reason, a so-called geometry factor is calculated from (c), and afterwards (b) is multiplied by this factor. The uncertainties are provided as standard uncertainties under the descriptor "MEASUREMENT UNCERTAINTY EXPRESSION" in the BUFR files.

Conformance result

Explanation

The underlying grid data are regularly compared with direct measurements of sunshine duration and global radiation at independent stations. There are only minor systematic differences (approx. 1 min for the sunshine duration, approx. 10 W/m2 for the global radiation, each approx. 5%); the mean absolute deviations were in the range of approx. 6 min and 30 W/m2, respectively. For specific situations, the deviations can be significantly lower or higher than the average. From version 006, the data also contain information on the uncertainty of the surface irradiance and the sunshine duration. These are estimated on the basis of the statistics of the differences between the satellite and the surface measurement data, the surrounding data variability and the geometric uncertainty of the cloud observation.
Pass
Yes

Conceptual consistency

Name of measure
quality_level
Measure description

The QUALITAETS_NIVEAU (QN) describes the scope of the input data used for merging.

Conformance result

Explanation

QN = 500 : DUETT data without station and satellite data

QN = 501 : DUETT data based on station data only

QN = 502 : DUETT data based on satellite data only

QN = 503 : DUETT data based on (max 42) station and satellite data
Pass
Yes
Statement

The underlying grid data are based on satellite observations and surface measurements. The used satellite data are generated by DWD in near-realtime every 15-min as instantaneous data of the suface radiation in 5 km resolution based on data from the geostationary Meteosat satellite. The surface measurements (aggregated over 10 min) are collected at 42 locations from the DWD netowork (mainly pyranometer instruments). Both data sets are aggregated to synoptic hourly data ((HH-1):50 to HH:50). A geo-statistical algorithm is used to generate the gridded data of surface irradiance and sunshine duration from those two data sources.
File identifier
urn:wmo:md:de-dwd-cdc:75a88e13-0725-4664-bf8a-2ea448b19504 XML
Metadata language
Deutsch
Character set
UTF8
Parent identifier
Gridded hourly near-realtime data of surface irradiance and sunshine duration based on surface measurements and satellite observations - DUETT Project

urn:wmo:md:de-dwd-cdc:2586457f-ffd1-4998-960d-3064beea1e34
Hierarchy level
Dataset
Date stamp
2025-04-04T13:36:21
Metadata standard name

ISO 19115-2 Geographic information Metadata Part 2: Extensions for imagery and gridded data
Metadata standard version

ISO 19115-2:2009-02-15
Point of contact
  Deutscher Wetterdienst - CDC - Vertrieb Klima und Umwelt
Frankfurter Strasse 135 , Offenbach , Hessen , 63067 , Deutschland
+ 49 (0) 69 8062-4400
+ 49 (0) 69 8062-4499
https://dwd.de
Hours of service

09:00 - 16:00
Dataset URI

urn:wmo:md:de-dwd-cdc:75a88e13-0725-4664-bf8a-2ea448b19504
 
 

Overviews

overview overview

Spatial extent

N
S
E
W
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Keywords

GEMET - INSPIRE themes, version 1.0
Atmosphärische Bedingungen Meteorologisch-geografische Kennwerte

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