Qatar: Meteosat Solar Data

This is the second article in a series on Meteosat solar data from EUMETSAT.  The intent is to define the basic parameters of meteorological data coverage for the State of Qatar.  Specifically:

  • Simple trigonometry is defined to assess the resolution of the satellite coverage area; 
  • A land surface analysis is conducted to visualize the geographic coordinates of the satellite pixels across the State of Qatar; 

The geographic pixel coordinates of a Meteosat satellite are a series of standardized pixel locations across the Earth’s surface, created through data processing, which map to digital coordinates in the satellite data files.  Clear understanding of pixel locations, both geographic and digital, is essential to solar data extractions.  Each pixel contains high-frequency, long-term time-series data.  Data available by pixel includes land surface radiation, temperature, barometric pressure, wind speeds, water vapor, cloud mask, and basic aerosol information.  Data downloads can be secured from the Satellite Application Facility (SAF), EUMETSAT, Lisboa Portugal.

Spatial Resolution

Let:

Re = the Earth’s radius = 6378.14 km
d.lat(i, j) = change in lat for pixel i,j
d.lon(i,j) = change in lon for pixel i,j
lat = latitude in radians of pixel i,j

Spatial resolution in the North-South direction (ResNS) and the West-East direction (ResWE) are given by:

ResNS = Re * d.lat
ResWE = Re * d.lon * cos(lat)

Hence, Meteosat solar data resolution will vary based on the curvature of the Earth and given a specific longitude and latitude:

Land Surface Analysis The SAF web site has a section for registered users with static data and tools located here, and includes data in HDF5 format with the geographic coordinates of the satellite pixels.  The land surface image at the start of this article was generated in R using spatial data objects and the following code:

This entry was posted in Data, GDAL, GIS, Qatar RE, Resource Assessment, Solar, Spatial Analysis. Bookmark the permalink.

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