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RadxBeamBlock

From Lrose Wiki

RadxBeamBlock estimates the amount of beam blockage due to terrain near a radar.

Overview

Overall, RadxBeamBlock takes elevation data, the radar location, and radar characteristics to estimate how much blockage occurs due to terrain.


Prerequesites

The following items are required:

  • Digital elevation model data
  • Radar antenna location
  • Radar characteristics
  • Parameter files for RadxBeamBlock.


Digital elevation model data

The supported digital elevation models include Shuttle Radar Topography Mission and ESRI grid data (spheroid). SRTM data can be found online here.


Radar location and characteristics

The radar location requires the latitude, longitude, and elevation of the antenna (ground level + radar height). In addition, characteristics including the wavelength, beamwidth, gate spacing, azimuths, and elevation angles are required.


Parameter files

RadxBeamBlock uses one parameter file. Compared to other Radx applications, the RadxBeamBlock parameter file requires just a few edits in order to run. Most of the parameters that need to be changed relate to the radar characteristics.

1) Main parameter file

Ensure file is up to date

To obtain the default parameter file, use the following command:

/path/to/lrose/install/bin/RadxBeamBlock -print_params > param_file_name

If you already have a parameter file and simply want to check for (and add) updated parameters while retaining current parameters, use the following command:

/path/to/lrose/install/bin/RadxBeamBlock -params orig_param_file_name -print_params > new_param_file_name

Important parameters

Input params

  • input_dem_parth: directory containing the elevation data
  • input_data_format: specifies the format of the elevation data (examples provided in the parameter file)

Radar parameters

  • radar_location: latitude, longitude, and elevation (ground elevation
    • radar height in km) of the radar antenna
  • radar_wavelength_cm: radar wavelength (cm)
  • horiz_beam_width_deg: horizontal beamwidth (degrees)
  • vert_beam_width_deg: horizontal beamwidth (degrees)
  • gates: starting distance, gate spacing (km), and number of gates
  • azimuths: starting azimuth, azimuth spacing (degrees), and number of azimuths
  • elevations: starting elevation angle, angle spacing (degrees), and number of elevation angles

Output directory and file name

  • output_dir: files will be written to this directory
  • output_format: select the preferred file type (usually CFRADIAL)


Running RadxBeamBlock

To check all command line options for RadxBeamBlock, including debugging options and file paths, type the following command into a terminal.

/path/to/lrose/install/bin/RadxBeamBlock -h

Once your parameter file is complete, use a command similar to the following to run the application:

/path/to/lrose/install/bin/RadxBeamBlock -params param_file_name