:orphan:

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.. CUI
..
.. The Advanced Framework for Simulation, Integration, and Modeling (AFSIM)
..
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WsfEarthJ2Term
--------------

.. class:: WsfEarthJ2Term inherits WsfOrbitalDynamicsTerm

Overview
========

The :class:`WsfEarthJ2Term` represents the additional acceleration due to the
oblateness of the Earth. See also :ref:`Earth J2 Perturbation <orbital_dynamics_terms.earth_j2>`.

Static Methods
==============

.. method:: WsfEarthJ2Term Construct()

   Construct a :class:`WsfEarthJ2Term` using default values of the gravitational
   parameter (3.986004415e+14 m^3/s^2), the mean radius of the Earth (6371.0 km),
   and :math:`J_2` (0.0010826267).

.. method:: WsfEarthJ2Term Construct(double aGravitationalParameter, double aMeanRadius, double aJ2)

   Construct a :class:`WsfEarthJ2Term` using the given gravitational parameter
   in SI units, the given mean radius of the Earth in meters, and the given
   value for :math:`J_2`.

.. method:: double DefaultJ2()

   Return the default value for :math:`J_2` (0.0010826267).

Methods
=======

.. method:: double GravitationalParameter()

   Return the gravitational parameter in SI units used by this term.

.. method:: double MeanRadius()

   Return the mean radius in meters of the Earth used by this term.

.. method:: double J2()

   Return the value of :math:`J_2` used by this term.

.. method:: Vec3 ComputeAcceleration(double aMass, Calendar aTime, Vec3 aPosition, Vec3 aVelocity)

   For the :class:`WsfEarthJ2Term` this method will return the zero vector; the
   acceleration provided by this term can only be computed when the dynamics are
   fully initialized and are in use by a :class:`WsfIntegratingSpaceMover`.