:orphan:

.. ****************************************************************************
.. CUI
..
.. The Advanced Framework for Simulation, Integration, and Modeling (AFSIM)
..
.. The use, dissemination or disclosure of data in this file is subject to
.. limitation or restriction. See accompanying README and LICENSE for details.
.. ****************************************************************************

WsfDriftManeuver
----------------

.. class:: WsfDriftManeuver inherits WsfOrbitalManeuver

**Input type:** :doc:`drift<../drift>`

:class:`WsfDriftManeuver` is used to move a platform on a circular orbit to a similar circular orbit in which the platform would advance or recede from its initial orbit at a given angular rate. The initial and final orbits do not intersect, and so there is a third transfer orbit that the executing platform will perform while moving from one radius to the next. This transfer can be optimized for duration or for delta-V usage, or it can be given a fixed duration. When the transfer ends, the platform will have a state that will have already drifted the correct amount based on the time of transfer.

Methods
*******

.. method:: static WsfDriftManeuver Construct(WsfOrbitalEventCondition aCondition, int aOptimizeOption, double aMaximumDeltaTime, double aMaximumDeltaV, double aDriftRate)

   Create a :class:`WsfDriftManeuver` with the intent of finding an optimal transfer solution in delta-V or time, using the following:

   * **aCondition**: A specific :class:`WsfOrbitalEventCondition` that specifies when the transfer to the final drifting orbit should begin. The provided condition must be :method:`WsfOrbitalEventCondition.NONE`, :method:`WsfOrbitalEventCondition.AT_RELATIVE_TIME`, :method:`WsfOrbitalEventCondition.AT_ASCENDING_NODE`, :method:`WsfOrbitalEventCondition.AT_DESCENDING_NODE`, :method:`WsfOrbitalEventCondition.AT_ECLIPSE_ENTRY`, or :method:`WsfOrbitalEventCondition.AT_ECLIPSE_EXIT`.
   * **aOptimizeOption**: The return value from :method:`WsfDriftManeuver.EARLIEST_TIME` or :method:`WsfDriftManeuver.LEAST_DELTA_V`, specifying if the transfer should solve for the least time of transfer, or the least delta-V for the transfer.
   * **aMaximumDeltaTime**: The maximum time in seconds after the transfer begins to consider in computing a solution.
   * **aMaximumDeltaV**: The maximum delta-V in meters per second to consider when computing a solution.
   * **aDriftRate**: The rate in degrees per second the final orbit will drift relative to the initial orbit.

.. method:: static WsfDriftManeuver Construct(WsfOrbitalEventCondition aCondition, WsfOrbitalOptimizationCost aCost, double aMaximumDeltaTime, double aMaximumDeltaV, double aDriftRate)

   Create a :class:`WsfDriftManeuver` with the intent of finding a transfer solution minimizing a given cost, using the following:

   * **aCondition**: A specific :class:`WsfOrbitalEventCondition` that specifies when the transfer to the final drifting orbit should begin. The provided condition must be :method:`WsfOrbitalEventCondition.NONE`, :method:`WsfOrbitalEventCondition.AT_RELATIVE_TIME`, :method:`WsfOrbitalEventCondition.AT_ASCENDING_NODE`, :method:`WsfOrbitalEventCondition.AT_DESCENDING_NODE`, :method:`WsfOrbitalEventCondition.AT_ECLIPSE_ENTRY`, or :method:`WsfOrbitalEventCondition.AT_ECLIPSE_EXIT`.
   * **aCost**: A :class:`WsfOrbitalOptimizationCost` instance specifying the cost function to minimize.
   * **aMaximumDeltaTime**: The maximum time in seconds after the transfer begins to consider in computing a solution.
   * **aMaximumDeltaV**: The maximum delta-V in meters per second to consider when computing a solution.
   * **aDriftRate**: The rate in degrees per second the final orbit will drift relative to the initial orbit.

.. method:: static WsfDriftManeuver Construct(WsfOrbitalEventCondition aCondition, double aDeltaTime, double aDriftRate)

   Create a :class:`WsfDriftManeuver` without optimizing the transfer, taking a fixed time to complete the transfer:

   * **aCondition**: A specific :class:`WsfOrbitalEventCondition` that specifies when the transfer to the final drifting orbit should begin. The provided condition must be :method:`WsfOrbitalEventCondition.NONE`, :method:`WsfOrbitalEventCondition.AT_RELATIVE_TIME`, :method:`WsfOrbitalEventCondition.AT_ASCENDING_NODE`, :method:`WsfOrbitalEventCondition.AT_DESCENDING_NODE`, :method:`WsfOrbitalEventCondition.AT_ECLIPSE_ENTRY`, or :method:`WsfOrbitalEventCondition.AT_ECLIPSE_EXIT`.
   * **aDeltaTime**: The time in seconds to complete the transfer.
   * **aDriftRate**: The rate in degrees per second the final orbit will drift relative to the initial orbit.

.. method:: static int EARLIEST_TIME()

   Return the value to be used when constructing a :class:`WsfDriftManeuver` when optimizing the maneuver such that it will complete at the earliest possible time, up to delta-t and delta-V constraints provided during construction.

.. method:: static int LEAST_DELTA_V()

   Return the value to be used when constructing a :class:`WsfDriftManeuver` when optimizing the maneuver such that it will execute with the least possible delta-v, up to delta-t and delta-V constraints provided during construction.

.. method:: double DriftRate()

   Return the drift rate in degrees per second.

.. method:: void SetDriftRate(double aDriftRate)

   Set the drift rate in degrees per second to the given value.