RK89 Object

Description

The Runge Kutta 8(9) propagator uses 8th order Runge-Kutta propagation with 9th order error control to propagate the spacecraft orbit. See expanded description.

Inheritance Hierarchy: Object->Propagator->Integrator->RK89

Available In Editions:

Engineer

Mission

Timing Precision Mode

This page describes functionality in millisecond timing precision mode. Millisecond timing precision mode is deprecated and will be removed in a future release. We recommend that you migrate your Mission Plans to nanosecond timing precision mode.

Click here to see the documentation for this object in nanosecond timing precision mode.

Name	Description	Attributes
AllowErrorViolation	Determines whether the error tolerance may be violated once the minimum step size is reached. If this property is set to true, and the integrator step error does not meet the tolerance at 1 ms step size, the state is automatically advanced 1 ms ahead and a warning is generated.	Type: Variable Access: Read/Write
CalculateSTM	Flag indicating whether or not to calculate the state transition matrix at each integration step as part of the state integration. If the PropagateCovariance flag is set to true on the SpacecraftODProperties object or if the Spacecraft is in an estimation process, the STM is always calculated. If the Spacecraft.Propagator is not an Integrator type then this property is ignored.	Type: Variable Access: Read/Write
DeclaredName	The name of the object as declared.	Type: String Access: Read-Only
FixedStep	Flag denoting whether the propagator is being run in fixed-step mode (i.e. constant StepSize) or in variable-step mode (i.e. variable StepSize).	Type: Variable Access: Read/Write
ForceModel	A force model.	Type: ForceModel Access: Read-Only
LargeCurvature	Flag that signifies whether the integration has failed due to a large curvature in the force field. (1 = Integration Failed, 0 = Integration Nominal, -1 = No Integration has been performed).	Type: Variable Access: Read-Only
MaxTries	The maximum number of times to attempt to change the step size in the integration process in order to meet the specified error tolerance. If the specified error tolerance is not met after MaxTries attempts, an error is thrown.	Type: Variable Access: Read/Write
Name	The name displayed for this object in output windows such as views, plots, and reports.	Type: String Access: Read/Write
ObjectId	The unique identifier for the object.	Type: Variable Access: Read-Only
ObjectType	The type of the object.	Type: String Access: Read-Only
RelativeErrorThreshold	If the absolute error is less than this value, then the absolute error is compared against the tolerance. Otherwise the relative error is compared against the tolerance. Set a very large value (e.g. 1e100) to ensure the RK89.Tolerance is treated as an absolute error tolerance. Set a very small value (e.g. 1e-100) to ensure that the RK89.Tolerance is treated as a relative error tolerance.	Type: Variable Access: Read/Write
StepJustTaken	The size of the previous step taken by the integration process.	Type: Variable Access: Read-Only Units: s
StepsAttempted	This represents the sum of the successful and failed steps. This property will closely reflect the performance of the integrator since it is a measure of the total number of steps executed by the integrator.	Type: Variable Access: Read-Only
StepsFailed	This property is incremented once each time the integrator steps the spacecraft forward and the integrator tolerance is not met. A high ratio of the number of failed to successful steps may suggest that the integrator tolerance is too high.	Type: Variable Access: Read-Only
StepSize	The number of seconds the propagated object is advanced when the Step command is executed.	Type: Variable Access: Read/Write Units: s
StepsRequested	Represents the count of integration steps requested by the user. This property will be incremented once each time the FreeFlyer engine advances the spacecraft to a desired epoch. For the Step command, this property will be incremented once. For interval methods and Step-to commands, this property will be incremented each time bisection is performed unitl the condition is met. Abnormally high values on this property can indicate that the IntervalStopAccuracy may be too strict.	Type: Variable Access: Read-Only
StepsSuccessful	This property is incremented for every successful step of the integrator. Since it may take several steps to reach the desired epoch at the specified tolerance, the number of successful steps may be greater than the number of requested steps.	Type: Variable Access: Read-Only
StepToTake	The maximum possible size of the next step to take in the integration process based on the relative error tolerance. When the StepSize property is set, this property is initialized with the new StepSize value and is updated after the next step is taken.	Type: Variable Access: Read-Only Units: s
STM	Returns the State Transition Matrix. The matrix is always a square where the length of each side is determined by the total number of properties being estimated or considered.	Type: Matrix Access: Read-Only
STMCalculationMethod	A flag indicating the method to be used to calculate the state transition matrix. Note that even if the CalculateSTM property is set to false, this property still applies if the SpacecraftODProperties.PropagateCovariance flag is to true or if the Spacecraft is included in an estimation process.	Type: Variable Access: Read/Write
Tolerance	When the Step command is executed, intermediate integration steps are taken to ensure that the local error never exceeds this value.	Type: Variable Access: Read/Write
ToleranceMode	Determines how the relative error tolerance is calculated.	Type: Variable Access: Read/Write