WSF_COMPOSITE_GRID

grid WSF_COMPOSITE_GRID
grid <name> WSF_COMPOSITE_GRID
   ... Common Grid Commands ...
   subgrid ... end_subgrid
end_grid

Overview

The WSF_COMPOSITE_GRID is a coverage grid defined by composing sub-grids. This is useful for computing coverage over geographically separated regions. These sub-grids can be of any available grid type (see Predefined Coverage Grid Types) that create their own platforms. Each sub-grid defined must have a unique name among the sub-grids of this grid. Sub-grids will inherit central_body and suppress_grid_platforms from this grid. grid_data_file will be ignored on the sub-grids of this grid.

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

subgrid <name> <grid-type> … end_subgrid

Add a sub-grid of the given <grid-type> with the given <name> to this grid. The subgrid is then configured according to the selected type, and will support any command that the selected grid type supports. The types of sub-grids supported are those that create their own platforms.