: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.
.. ****************************************************************************

WSF_KALMAN_FILTER
-----------------

.. model:: filter WSF_KALMAN_FILTER

.. parsed-literal::

   filter <name> :model:`WSF_KALMAN_FILTER`
      ... Commands_ ...
   end_filter
 
Overview
========

Defines a Kalman filter for filtering tracks.  The filter accepts input locations (from range, bearing, elevation, or
location measurements).  It produces an estimate of the tracked target's location and velocity, as well as a state
covariance matrix.

.. block:: WSF_KALMAN_FILTER

Commands
========

.. command:: process_noise_sigmas_XYZ <X-value> <Y-value> <Z-value>
   
   Defines the filter's noise standard deviation for the three directions.  The values are accelerations in the
   :ref:`entity coordinate system (ECS) <coordinate_systems>` of the tracked platform.  They must be entered in meters per
   second squared.  See `Process Noise Recommended Values`_ below for example inputs.
   
   Default:  0 0 0 

.. command:: process_noise_model  [constant_velocity; constant_acceleration] 
   
   Selects the filter's process noise model, either one based on a constant velocity of the target or a constant
   acceleration of the target.
   
   Default:  constant_velocity 

.. command:: debug
   
   Writes debugging information to the standard output.

.. command:: range_measurement_sigma <length-value>
   
   Defines the standard deviation that is applied to the measurement's range prior to filtering.

   .. note::
   
      This input is usually not needed.  It is only used if there is no range error on the associated
      track.
   
   Default:  0 m 

.. command:: bearing_measurement_sigma <length-value>
   
   Defines the standard deviation that is applied to the measurement's bearing prior to filtering.

   .. note::
   
      his input is usually not needed.  It is only used if there is no bearing error on the associated
      track.
   
   Default:  0 deg 

.. command:: elevation_measurement_sigma <length-value>
   
   Defines the standard deviation that is applied to the measurement's elevation prior to filtering.

   .. note::
   
      This input is usually not needed.  It is only used if there is no elevation error on the associated
      track.
   
   Default:  0 deg 

Process Noise Recommended Values
================================

**Constant Acceleration Model**

   +-----------------------+---------+---------+---------+
   | Platform Category     | Sigma X | Sigma Y | Sigma Z |
   +=======================+=========+=========+=========+
   | High Agility Aircraft | 50.0    | 10.0    | 50.0    |
   +-----------------------+---------+---------+---------+
   | Truck / Car           | 2.0     | 2.0     | 0.2     |
   +-----------------------+---------+---------+---------+
   | Naval Ship            | 1.0     | 2.0     | 2.0     |
   +-----------------------+---------+---------+---------+

**Constant Velocity Model**

   +-----------------------+---------+---------+---------+
   | Platform Category     | Sigma X | Sigma Y | Sigma Z |
   +=======================+=========+=========+=========+
   | High Agility Aircraft | 2.0     | 2.0     | 2.0     |
   +-----------------------+---------+---------+---------+
   | Truck / Car           | 0.1     | 0.2     | 0.2     |
   +-----------------------+---------+---------+---------+
   | Naval Ship            | 0.4     | 0.4     | 2.0     |
   +-----------------------+---------+---------+---------+