Plugin Models: Atmospheric Density, Drag, and Solar Pressure Reflection

ODTK provides singular plugin points for the customization of the computation of the atmospheric density, air drag force, and solar pressure force used in the propagation of the satellite trajectory.

This is a fixed list. Each row contains data for one of the "N" Drag Model or Solar Pressure Reflection Plugin Model parameters.

These sub-attributes are hidden unless you set the Satellite().ForceModel.Drag.AtmDensityModel attribute to "DensityPlugin," the Satellite().ForceModel.DragModel attribute to "DragModelPlugin," or the Satellite().ForceModel.SolarPressure.SRPModel attribute to "ReflectionPlugin." There is an independent set of options for each plugin point.

Plugin Model Options
Option	Description
PluginID	Select the desired plugin from the dropdown list. The plugin must be registered to appear in the list. See the plugin registration section for instructions on registering the plugin.
PluginConfig	These are configuration parameters for the selected plugin, which are hidden until you select the PluginID.
PluginParameters	This is a list of settings for the parameters used in the model that may be estimated. The plugin supplies this list of parameters. See the list attributes in the table below. These parameters are not available for atmospheric density plugin models.

Estimated parameters associated with plugin atmospheric density models are exposed through the Global Atmospheric Density Estimation setting of the Simulator, Filter, and Smoother.

Plugin parameters

This is a fixed list. Each row contains data for one of the "N" Solar Pressure Reflection Plugin Model parameters. You have the option to designate a parameter as a state parameter, where ODTK models all estimated plugin parameters as a Gauss Markov parameter. Included are:

Plugin Parameters
Attribute	Description
Name	This is the name of the parameter used in reporting, as defined within the plugin itself. You can access the parameter in the scripting interface by referring to it as Drag.<Name> or SolarPressure.<Name>.
Nominal	This is the "nominal" value of the parameter .
EstimateParameter	Set this to True to have ODTK estimate the parameter.
InitialEstimate	This is the initial state estimate of the bias from the Nominal.
Halflife	This is the state estimate bias error half-life in time units.
Sigma	This is the uncertainty in the Nominal bias.
StateScaling	ODTK uses this for covariance normalization, i.e., to scale the values of a parameter's estimate and covariance so that the "nominal" variance kept in the covariance matrix when doing the matrix operations is "near" unity, to help in numerical precision.
TransitionPert	This is a numerical perturbation epsilon that ODTK uses in the numerical computation of the state transition partials. Use this control when setting the OrbitErrorTransitionMethod to Numerical.

See ODTK Plugins for further information.