WSF_JACCHIA_ROBERTS_ATMOSPHERE

Script Type: WsfJacchiaRobertsAtmosphere.

atmosphere_model WSF_JACCHIA_ROBERTS_ATMOSPHERE
atmosphere_model <name> WSF_JACCHIA_ROBERTS_ATMOSPHERE
   ... Common Atmosphere Commands ...
   solar_flux ...
   average_solar_flux ...
   geomagnetic_index ...
end_atmosphere_model

Overview

The WSF_JACCHIA_ROBERTS_ATMOSPHERE provides an atmosphere model that models the exospheric temperature profile, with dependence on solar and geomagnetic activity. The density is then obtained for various altitude zones. For details, see Vallado’s Fundamentals of Astrodynamics and Application, Fourth Edition, Appendix B.

Common Atmosphere Commands

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.

Commands

solar_flux <real-value>

Set the 10.7 cm solar flux, in units of 10^{-22} \rm{W}/\rm{m}^2/\rm{Hz}, that will be used by this atmosphere model. Reasonable values for this are in the range [50, 400]. This value is the average of the flux on the day of interest.

Default: 150

average_solar_flux <real-value>

Set the average of the 10.7 cm solar flux, in units of 10^{-22} \rm{W}/\rm{m}^2/\rm{Hz}, that will be used by this atmosphere model. Reasonable value for this are in the range [50, 400]. This value is the 81 day running average flux centered on the day of interest.

Default: 150

geomagnetic_index <real-value>

Set the geomagnetic activity, K_p. The provided value must be in the range [0, 9].

Default: 0