agi.foundation.celestial

(agi.foundation.orbitpropagation-2024r3.jar)

Class SimpleSolarRadiationForce

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.celestial.ForceModel

agi.foundation.celestial.SimpleSolarRadiationForce

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable, IPartialDifferentiable

public class SimpleSolarRadiationForce
extends ForceModel
implements IPartialDifferentiable

Represents the acceleration from solar radiation pressure exerted on the given reflective area at the target position.

Constructor Summary

Constructors

Modifier	Constructor and Description
	SimpleSolarRadiationForce() Initializes a new instance.
	SimpleSolarRadiationForce(Point targetPoint, Scalar reflectivityCoefficient, Scalar referenceArea) Creates a instance based on the given target point and its coefficients.
	SimpleSolarRadiationForce(ScalarOccultation occultationFactor, Scalar reflectivityCoefficient, Scalar referenceArea) Creates a instance based on a given ScalarOccultation and the coefficients of reflectivity.
protected	SimpleSolarRadiationForce(SimpleSolarRadiationForce existingInstance, CopyContext context) Initializes a new instance as a copy of an existing instance.

Method Summary

Modifier and Type	Method and Description
void	buildForceEvaluator(ResultantForceBuilder builder, EvaluatorGroup group) Build lists of principal and perturbation forces based on this model in order to create an overall resultant force.
protected boolean	checkForSameDefinition(ForceModel other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(SimpleSolarRadiationForce other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
Object	clone(CopyContext context) Clones this object using the specified context.
protected int	computeCurrentDefinitionHashCode() Computes a hash code based on the current properties of this object.
void	enumerateDependencies(DependencyEnumerator enumerator) Enumerates the dependencies of this object by calling DependencyEnumerator#enumerate(T) for each object that this object directly depends upon.
Scalar	getCoefficientOfReflectivity() Gets the coefficient of reflectivity.
CoefficientOfReflectivityType	getCoefficientOfReflectivityType() Gets the CoefficientOfReflectivityType, which is set to CoefficientOfReflectivityType.RADIATION_PRESSURE by default.
Axes	getDefinedInAxes() Gets the axes in which this force is defined.
int	getDimension() Gets the dimension of the values produced by the object.
Scalar	getLuminosity() Gets the Scalar describing the solar luminosity.
ScalarOccultation	getOccultationFactor() Gets the scalar modeling the amount of occultation at the target position.
PartialDerivativesEvaluator	getPartialDerivativesEvaluator(List<IPartialDifferentiable> independentVariables, EvaluatorGroup group) Gets an evaluator that calculates the partial derivatives of the solar radiation force with respect to any of the independentVariables parameters that apply, generally the position.
Scalar	getReferenceArea() Gets the Scalar representing the normalized area of the surface.
Point	getTargetPoint() Gets the point at which the solar radiation is applied from the TargetPoint (get / set) of the OccultationFactor (get / set).
RadiationVectorType	getVectorType() Gets the RadiationVectorType from the VectorType (get / set) of the OccultationFactor (get / set).
void	setCoefficientOfReflectivity(Scalar value) Sets the coefficient of reflectivity.
void	setCoefficientOfReflectivityType(CoefficientOfReflectivityType value) Sets the CoefficientOfReflectivityType, which is set to CoefficientOfReflectivityType.RADIATION_PRESSURE by default.
void	setLuminosity(Scalar value) Sets the Scalar describing the solar luminosity.
void	setOccultationFactor(ScalarOccultation value) Sets the scalar modeling the amount of occultation at the target position.
void	setReferenceArea(Scalar value) Sets the Scalar representing the normalized area of the surface.

Methods inherited from class agi.foundation.celestial.ForceModel

checkForSameDefinition, freezeAggregatedObjects, getForceEvaluator, getForceEvaluator, getForceVector, getKind, getRole

Methods inherited from class agi.foundation.infrastructure.DefinitionalObject

areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, dictionaryItemsAreSameDefinition, freeze, getCollectionHashCode, getCollectionHashCode, getCollectionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDictionaryHashCode, getIsFrozen, isSameDefinition, throwIfFrozen

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface agi.foundation.infrastructure.IEquatableDefinition

getDefinitionHashCode, isSameDefinition

Constructor Detail

SimpleSolarRadiationForce

public SimpleSolarRadiationForce()

Initializes a new instance. The Luminosity (get / set) property is set to a ScalarFixed with a value of Constants.SolarLuminosity2015IauResolutionB3. CoefficientOfReflectivityType (get / set) is set to CoefficientOfReflectivityType.RadiationPressure.

The OccultationFactor (get / set), CoefficientOfReflectivity (get / set), and ReferenceArea (get / set) properties must be set before an Evaluator is created.

SimpleSolarRadiationForce

public SimpleSolarRadiationForce(Point targetPoint,
                                 Scalar reflectivityCoefficient,
                                 Scalar referenceArea)

Creates a instance based on the given target point and its coefficients.

Parameters:

targetPoint - The target point used to define the geometry required for the ScalarOccultation, including the SunCentralBody as the illuminating body and the EarthCentralBody and MoonCentralBody as occluding bodies.

reflectivityCoefficient - The reflectivity coefficient of the satellite.

referenceArea - The reference area of the satellite used to model radiation pressure.

SimpleSolarRadiationForce

public SimpleSolarRadiationForce(ScalarOccultation occultationFactor,
                                 Scalar reflectivityCoefficient,
                                 Scalar referenceArea)

Creates a instance based on a given ScalarOccultation and the coefficients of reflectivity.

Parameters:

occultationFactor - The ScalarOccultation that models the occultation of the sun.

reflectivityCoefficient - The reflectivity coefficient of the satellite.

referenceArea - The reference area of the satellite used to model radiation pressure.

SimpleSolarRadiationForce

protected SimpleSolarRadiationForce(@Nonnull
                                    SimpleSolarRadiationForce existingInstance,
                                    @Nonnull
                                    CopyContext context)

Initializes a new instance as a copy of an existing instance.

See ICloneWithContext.clone(CopyContext) for more information about how to implement this constructor in a derived class.

Parameters:

existingInstance - The existing instance to copy.

context - A CopyContext that controls the depth of the copy.

Throws:

ArgumentNullException - Thrown when existingInstance or context is null.

Method Detail

clone

public Object clone(CopyContext context)

Clones this object using the specified context.

This method should be implemented to call a copy constructor on the class of the object being cloned. The copy constructor should take the CopyContext as a parameter in addition to the existing instance to copy. The copy constructor should first call CopyContext.addObjectMapping(T, T) to identify the newly constructed instance as a copy of the existing instance. It should then copy all fields, using CopyContext.updateReference(T) to copy any reference fields.

A typical implementation of ICloneWithContext:

public static class MyClass implements ICloneWithContext {
    public MyClass(MyClass existingInstance, CopyContext context) {
        context.addObjectMapping(existingInstance, this);
        someReference = context.updateReference(existingInstance.someReference);
    }

    @Override
    public final Object clone(CopyContext context) {
        return new MyClass(this, context);
    }

    private Object someReference;
}

In general, all fields that are reference types should be copied with a call to CopyContext.updateReference(T). There are a couple of exceptions:

1. Fields that are aggregate parts of the object should always be copied. A referenced object is an aggregate if properties or methods on the object being copied can modify the externally-visible value of the referenced object.
2. If the semantics of the referenced object require that it have a single parent, owner, context, etc., and the object being copied is that parent, owner, or context, then the referenced object should always be copied.

If one of these exceptions applies, the CopyContext should be given an opportunity to update the reference before the reference is copied explicitly. Use CopyContext.updateReference(T) to update the reference. If CopyContext.updateReference(T) returns the original object, indicating that the context does not have a replacement registered, then copy the object manually by invoking a Clone method, a copy constructor, or by manually constructing a new instance and copying the values.

alwaysCopy = context.updateReference(existingInstance.alwaysCopy);
if (existingInstance.alwaysCopy != null && alwaysCopy == existingInstance.alwaysCopy) {
    alwaysCopy = (AlwaysCopy) existingInstance.alwaysCopy.clone(context);
}

If you are implementing an evaluator (a class that implements IEvaluator), the IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) method shares some responsibilities with the copy context constructor. Code duplication can be avoided by doing the following:

1. For references to other evaluators ONLY, simply assign the reference in the constructor instead of calling CopyContext.updateReference(T). You should still call CopyContext.updateReference(T) on any references to non-evaluators.
2. Call IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) as the last line in the constructor and pass it the same CopyContext passed to the constructor.
3. Implement IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) as normal. See the reference documentation for IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) for more information on implementing that method.

public MyClass(MyClass existingInstance, CopyContext context) {
    super(existingInstance, context);
    someReference = context.updateReference(existingInstance.someReference);
    evaluatorReference = existingInstance.evaluatorReference;
    updateEvaluatorReferences(context);
}

@Override
public void updateEvaluatorReferences(CopyContext context) {
    evaluatorReference = context.updateReference(evaluatorReference);
}

@Override
public Object clone(CopyContext context) {
    return new MyClass(this, context);
}

private Object someReference;
private IEvaluator evaluatorReference;

Specified by:

clone in interface ICloneWithContext

Specified by:

clone in class DefinitionalObject

Parameters:

context - The context to use to perform the copy.

Returns:

A new instance which is a copy of this object.

checkForSameDefinition

protected final boolean checkForSameDefinition(ForceModel other)

Checks to determine if another instance has the same definition as this instance and returns true if it does. Derived classes MUST override this method and check all new fields introduced by the derived class for definitional equivalence. It is NOT necessary to check base class fields because the base class will already have done that. When overriding this method, you should NOT call the base implementation because it will return false for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IEquatableDefinition.isSameDefinition(java.lang.Object).

Specified by:

checkForSameDefinition in class ForceModel

Parameters:

other - The other instance to compare to this one.

Returns:

true if the two objects are defined equivalently; otherwise false.

checkForSameDefinition

protected boolean checkForSameDefinition(SimpleSolarRadiationForce other)

Checks to determine if another instance has the same definition as this instance and returns true if it does. Derived classes MUST override this method and check all new fields introduced by the derived class for definitional equivalence. It is NOT necessary to check base class fields because the base class will already have done that. When overriding this method, you should NOT call the base implementation because it will return false for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IEquatableDefinition.isSameDefinition(java.lang.Object).

Parameters:

other - The other instance to compare to this one.

Returns:

true if the two objects are defined equivalently; otherwise false.

computeCurrentDefinitionHashCode

protected int computeCurrentDefinitionHashCode()

Computes a hash code based on the current properties of this object. Derived classes MUST override this method and compute a hash code that combines: a unique hash code seed, the base implementation result, and the hash codes of all new fields introduced by the derived class which are used in the SimpleSolarRadiationForce.checkForSameDefinition(agi.foundation.celestial.ForceModel) method.

Overrides:

computeCurrentDefinitionHashCode in class ForceModel

Returns:

The computed hash code.

enumerateDependencies

public void enumerateDependencies(DependencyEnumerator enumerator)

Enumerates the dependencies of this object by calling DependencyEnumerator#enumerate(T) for each object that this object directly depends upon. Derived classes which contain additional dependencies MUST override this method, call the base implementation, and enumerate dependencies introduced by the derived class.

Specified by:

enumerateDependencies in interface IEnumerateDependencies

Overrides:

enumerateDependencies in class ForceModel

Parameters:

enumerator - The enumerator that is informed of the dependencies of this object.

getDimension

public final int getDimension()

Gets the dimension of the values produced by the object. For example, Vectors would have a dimension of three, and Scalars of one. A PartialDerivativesEvaluator created by this type will have a RowDimension (get) equal to this property, and a ColumnDimension (get) equal to the summation of the dimensions of the independent variables that this object is dependent on.

Specified by:

getDimension in interface IPartialDifferentiable

getOccultationFactor

public final ScalarOccultation getOccultationFactor()

Gets the scalar modeling the amount of occultation at the target position. This scalar also holds the Point and other data.

setOccultationFactor

public final void setOccultationFactor(ScalarOccultation value)

Sets the scalar modeling the amount of occultation at the target position. This scalar also holds the Point and other data.

getTargetPoint

public final Point getTargetPoint()

Gets the point at which the solar radiation is applied from the TargetPoint (get / set) of the OccultationFactor (get / set). If the OccultationFactor (get / set) property is null, then this property will also return null.

getCoefficientOfReflectivity

public final Scalar getCoefficientOfReflectivity()

Gets the coefficient of reflectivity. To set the CoefficientOfReflectivityType see the CoefficientOfReflectivityType (get / set) property.

setCoefficientOfReflectivity

public final void setCoefficientOfReflectivity(Scalar value)

Sets the coefficient of reflectivity. To set the CoefficientOfReflectivityType see the CoefficientOfReflectivityType (get / set) property.

getDefinedInAxes

public final Axes getDefinedInAxes()

Gets the axes in which this force is defined. For solar radiation, the axes are taken from the inertial frame of the IlluminatingBody (get / set) on the OccultationFactor (get / set). If the OccultationFactor (get / set) property is null, then this property will also return null.

getCoefficientOfReflectivityType

@Nonnull
public final CoefficientOfReflectivityType getCoefficientOfReflectivityType()

Gets the CoefficientOfReflectivityType, which is set to CoefficientOfReflectivityType.RADIATION_PRESSURE by default. In order to set the value of the Coefficient of Reflectivity see CoefficientOfReflectivity (get / set).

setCoefficientOfReflectivityType

public final void setCoefficientOfReflectivityType(@Nonnull
                                                   CoefficientOfReflectivityType value)

Sets the CoefficientOfReflectivityType, which is set to CoefficientOfReflectivityType.RADIATION_PRESSURE by default. In order to set the value of the Coefficient of Reflectivity see CoefficientOfReflectivity (get / set).

getReferenceArea

public final Scalar getReferenceArea()

Gets the Scalar representing the normalized area of the surface.

setReferenceArea

public final void setReferenceArea(Scalar value)

Sets the Scalar representing the normalized area of the surface.

getVectorType

@Nonnull
public final RadiationVectorType getVectorType()

Gets the RadiationVectorType from the VectorType (get / set) of the OccultationFactor (get / set). If the OccultationFactor (get / set) property is null, then this property will return RadiationVectorType.CORRECT_FOR_LIGHT_TIME_DELAY_AND_ABERRATION.

getLuminosity

public final Scalar getLuminosity()

Gets the Scalar describing the solar luminosity. By default this is set to a ScalarFixed with the value of Constants.SolarLuminosity2015IauResolutionB3.

setLuminosity

public final void setLuminosity(Scalar value)

Sets the Scalar describing the solar luminosity. By default this is set to a ScalarFixed with the value of Constants.SolarLuminosity2015IauResolutionB3.

buildForceEvaluator

public void buildForceEvaluator(ResultantForceBuilder builder,
                                EvaluatorGroup group)

Build lists of principal and perturbation forces based on this model in order to create an overall resultant force.

Specified by:

buildForceEvaluator in class ForceModel

Parameters:

builder - The builder object containing the lists and additional information on the Axes in which the overall resultant is defined.

group - The evaluator group in which to create evaluators.

Throws:

PropertyInvalidException - Thrown when Luminosity (get / set), CoefficientOfReflectivity (get / set), OccultationFactor (get / set) or ReferenceArea (get / set) is null.

getPartialDerivativesEvaluator

public final PartialDerivativesEvaluator getPartialDerivativesEvaluator(List<IPartialDifferentiable> independentVariables,
                                                                        EvaluatorGroup group)

Gets an evaluator that calculates the partial derivatives of the solar radiation force with respect to any of the independentVariables parameters that apply, generally the position.

Specified by:

getPartialDerivativesEvaluator in interface IPartialDifferentiable

Parameters:

independentVariables - The list of IPartialDifferentiable representing the independent variables that the created partial derivative evaluator calculates partials with respect to.

group - The evaluator group to contain the evaluator.

Returns:

The PartialDerivativesEvaluator.