Configuration

A number of configuration steps are required before running AOSPRE. These steps are outlined below. It may be helpful also to review the the "Preliminaries and Prerequisites" documentation page.

Collect weather model output files

It is up to the user to either produce their own model simulation output or obtain output from another source. Without it, the AOSPRE cannot run. It is recommended to use a model output grid spacing no larger than 1 km, as higher resolutions are better able to represent atmospheric features and variability at the scales needed for AOSPRE to produce realistic simulated radar scans.

Make sure the model output files are in a location accessible from the AOSPRE run directory (i.e., not on a remote server). The files will be found at runtime by AOSPRE using the "wrf_glob_pattern" namelist option. Check to to see that the "wrf_glob_pattern" option will find the desired model output files.

Design a flight plan

The flight path through the simulation is set by namelist options "flight_waypoints_x", "flight_waypoints_y", and "flight_waypoints_z". The x and y coordinates are specified in by model grid point index, and the z coordinate may be specified in pressure (hPa) or height MSL (m) depending on the "flight_level_coordinate" namelist option. The flight path is traversed by straight line paths between successive (x,y,z) coordinates.

Designing a flight plan can be one of the more difficult parts of using AOSPRE. Users may find the ncview utility useful for examining the NWP simulation files and finding gridpoint coordinates at appropriate times and locations. The "flight_planner" shell script (in the "scripts" directory) might also be useful.

Once a flight plan is designed, users may want to run AOSPRE in a mode to create a few surveillance PPI scans along the flight path, and use these scans to verify that the flight plan is suitable for sampling the regions of interest in the NWP simulation, before running more extensive and compute-intensive flights and scanning strategies.

Configure CR-SIM options

CR-SIM options are configured in the CR-SIM configuration file. The file name for the CR-SIM configuration file is referenced in the AOSPRE "CRSIM_Config" namelist option.

Only specific settings in the CR-SIM configuration file are used by AOSPRE.

Configure AOSPRE namelist

Configure scanning tables

AOSPRE scanning tables are organized in a two-column format text file and contain information about the primary axis of rotation, sweep mode, and the information contained in each column (i.e., rotation and tilt angles). The basic scan files use Z as the primary axis of rotation with beams pointing at 240° and 275° relative to the aircraft fuselage. Tilt angles for the RHI scan are between -53° and 53.5° at intervals of 1.5° for a total of 72 beams per rotation angle. The surveillance scan mode uses a tilt of 0° with a full azimuthal rotation at intervals of 1.5° for a total of 241 beams.

The user can create their own scan tables as desired.

Sample scanning tables include:

  • Scanning_Table_LHS_PPI_sector_Z (for surveillance mode)
  • Scanning_Table_LHS_Multiplexing_RHI_Zprime_ordered (for left panel RHI)
  • Scanning_Table_RHS_Multiplexing_RHI_Zprime_ordered (for right panel RHI)

The scanning table file name is referenced in the AOSPRE namelist.

Program execution

Usage

executable namelist [namelist [namelist]]

MPICH usage

mpirun -n executable namelist [namelist [namelist]]

Output

CfRadial-format NetCDF files

CfRadial format is described in CfRadial document.