WSF_ZONE_BASED_GRID

grid WSF_ZONE_BASED_GRID
grid <name> WSF_ZONE_BASED_GRID
   ... Common Grid Commands ...
   zone ...
   spacing ...
   latitude_spacing ...
   longitude_spacing ...
   origin ...
   altitude ...
   asset ...
end_grid

Overview

The WSF_ZONE_BASED_GRID is a coverage grid with a regular arrangement of points in latitude and longitude, but with a boundary given by a user-specifiable zone. The separation between points in the grid is specified by angles in latitude and longitude. The north-south and east-west directions can have their separations set independently. The altitude of the grid is fixed, and can be specified.

Common Grid Commands

grid_data_file <file-name>

Specify the name of an output file that will be created containing details of the points in this grid. The specified file is created at the end of the simulation.

central_body … end_central_body
central_body <central-body-type>
   polar_offset_angles
end_central_body

Specify the central body and related ellipsoid model to be used by simulation platforms. Options for <central body type> are the following:

  • earth_wgs72 (Earth World Geodetic System 1972): The central body ellipsoid is defined according to the WGS-72 standard.

  • earth_wgs84 (Earth World Geodetic System 1984): The central body ellipsoid is defined according to the WGS-84 standard.

  • earth_egm96 (Earth Gravity Model 1996): The central body ellipsoid is defined according to the EGM-96 standard.

  • moon: The central body ellipsoid is defined according to published lunar parameters.

  • sun: The central body ellipsoid is defined according to published solar parameters.

  • jupiter: The central body ellipsoid is defined according to published Jovian parameters.

Default earth_wgs84

polar_offset_angles <angle-value> <angle-value>

Specify the central_body’s polar offset angles (x_p and y_p, respectively) of the Celestial Intermediate Pole (CIP) with respect to the WCS (ITRS) coordinate system. Providing these values (of the order of tenths of arc-seconds) enables very highly accurate conversions between ECI and WCS coordinates.

Default 0.0 rad 0.0 rad

Note

WCS->LLA conversions are affected by central body choice, as well as sidereal motion transforms calculated in inertial (ECI) coordinate conversions.

suppress_grid_platforms <boolean-value>

This command allows for the suppression of grid asset platforms in DIS output and in distributed simulations. This suppression only applies for platforms created by a grid. This suppression is enabled by default.

Commands

zone <global-zone-name>

Specify that the boundary of the grid should match the boundary for the global zone with the name <global-zone-name>.

spacing <angle-value>

Set the spacing between grid points in both latitude and longitude, but only if those spacings have not been set in some other way (latitude_spacing, or longitude_spacing).

latitude_spacing <angle-value>

Set the spacing between adjacent latitudes for this grid. If both latitude_spacing and spacing are defined, the value provided with latitude_spacing will be used.

longitude_spacing <angle-value>

Set the spacing between adjacent longitudes for this grid. If both longitude_spacing and spacing are defined, the value provided with longitude_spacing will be used.

origin <latitude-value> <longitude-value>

Set the origin on the point in the grid. The origin is the point from which the other points are spaced in latitude and longitude. The origin must be within the latitude and longitude rectangle that bounds the zone specified for this grid. The default value of the grid’s origin point is the centroid of the zone.

altitude <length-value> <altitude-reference>

Set the altitude of the grid points. <altitude-reference> can be either ‘msl’, in which case the altitude refers to a height above the mean sea level, or ‘agl’, in which case the altitude refers to a height above the ground level set by any terrain in the scenario.

asset <platform-type> <device-name>

Specify the assets associated with this grid will be instances of <platform-type> and will use the device with the name <device-name>. The given <device-name> may also be ‘none’ if the grid points are passive targets for the coverage computation in question.