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Reflectivity PPI data

This dataset contains the radar reflectivity plan position indicator (PPI) data derived from the five weather radars used in this case study.

Description

The dataset is a time series of reflectivity grids for each radar. It is structured as follows:

\ppi
    \radar1_date1.zip // Compressed data for first day of this radar
        radar1_date1_time1.txt // Grid of reflectivity data for this radar and timeframe
        radar1_date1_time2.txt
        radar1_date1_time3.txt
        ...
    ...
    \radar1_date7.zip // Compressed data for last day of this radar
    \radar2_date1.zip
    ...
\position
    radar1_latitudes.txt // Grid of the latitudes around this radar
    radar1_longitudes.txt // Grid of the longitudes around this radar
    radar2_latitudes.txt
    radar2_longitudes.txt
    ...

The radar reflectivity plan position indicator (PPI) data has been derived from the radar reflectivity data from a single scan of each radar. It is represented as a 120x120km Cartesian grid centered on the radar, with a horizontal resolution of 1km. In the data (e.g. radar1_date1_time1.txt) it is formatted as 120 rows and 120 columns, with each field (i.e. grid node) containing the radar reflectivity factor, given in dBZ.

In addition, the geospatial positions of the 5 grids are given in position, as the latitude and longitude for each grid node.

Conversion

The conversion from the measured radar reflectivity factors on a polar grid to a Cartesian grid is carried out as follows:

  • Construct Cartesian grid with a size of 120x120 km, centered around the radar, with a 1km resolution
  • For each Cartesian grid node, determine the coordinates in the radar polar coordinate system
  • Determine which polar pixel is closest to the Cartesian grid node
  • Assign the reflectivity of that polar pixel to the Cartesian pixel

Radar settings

The radar scans used for these PPIs are:

  • 6260 (De Bilt, Netherlands): 0.8 degrees elevation angle; height increases from 44m at the radar to 1094m at 60km from the radar
  • 6234 (Den Helder, Netherlands): 0.8 degrees elevation angle; height increases from 51m at the radar to 1101m at 60km from the radar
  • 6410 (Jabbeke, Belgium): 1.2 degrees elevation angle; height increases from 52 m at the radar to 1520m at 60km from the radar
  • 6451 (Zaventem, Belgium): 1.0 degrees elevation angle; height increases from 73m at the radar to 1332m at 60km from the radar
  • 6477 (Wideumont, Belgium): 1.2 degrees elevation angle; height increases from 592m at the radar to 2060m at 60km from the radar

Data

  • Bulk download PPI data: ppi
  • Bulk download geospatial positions: position

License

Creative Commons Zero

Contact

Hidde Leijnse