Coverage Grid

grid <name> <grid-type>
   central_body ...
   grid_data_file ...
   suppress_grid_platforms ...
end_grid

Coverage is computed at a fixed set of locations that form a coverage grid. Each coverage computation is required to specify the grid over which the computation is to occur, and multiple coverage computations can use the same grid.

Coverage Grid Commands

grid <name> <grid-type>

Specify a coverage grid. See Predefined Coverage Grid Types for a list of available coverage grid types.

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.

Predefined Coverage Grid Types