RadxEvad

Overview

RadxEvad reads in Doppler data from a polar radar file, computes volumetric VAD (VVP) winds and writes them out to NetCDF.

Prerequesites

The following items are required:

• Radar data (any Radx supported format, e.g., cfradial)

Parameter file

RadxEvad uses one parameter file that includes the basic parameters related to data location and field names, which is similar to the parameter files for the other Radx applications.

Ensure file is up to date

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

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

Important parameters

Data input

• input_dir: directory containing radar data (if not specified on the command line and if mode = REALTIME)
• mode: determines if the program waits for new files (REALTIME), moves through start and end times specified on the command line (ARCHIVE), or moves through list of files specified on the command line (FILELIST)

Input field information

• VEL_field_name: name of velocity field in input files

Input data censoring

• censor_using_thresholds: option to censor fields where gates meet certain criteria
• censor_field_name: name of field for thresholding
• censor_min_value: field must exceed this value for the gate to be accepted
• censor_max_value: field must be less than this value for the gate to be accepted

VAD computations

• min_elev: minimum elevation angle for data in VAD (deg)
• max_elev: maximum elevation angle for data in VAD (deg)
• min_range: minimum range for data in VAD (km)
• max_range: maximum range for data in VAD (km)

NetCDF output

• write_results_to_netcdf: option to write results to NetCDF files
• output_netcdf_dir: directory where NetCDF files will be written

SPDB output

• write_results_to_spdb: option to write results to SPDB files
• output_spdb_dir: directory where SPDB files will be written

Running RadxEvad

To check all command line options for RadxEvad, including debugging options and file paths, the typical '-h' flag can be invoked:

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

Likewise, to obtain the default parameter file, use the following command:

/path/to/lrose/install/bin/RadxEvad -print_params > RadxEvad.params

Use the following command to convert using the settings provided by the parameter file:

/path/to/lrose/install/bin/RadxEvad -f <path/to/data/file_name> -params $PWD/RadxEvad.params