org.orekit.ssa.collision.shorttermencounter.probability.twod

Class Patera2005

java.lang.Object

org.orekit.ssa.collision.shorttermencounter.probability.twod.AbstractShortTermEncounter2DPOCMethod

org.orekit.ssa.collision.shorttermencounter.probability.twod.AbstractShortTermEncounter1DNumerical2DPOCMethod

org.orekit.ssa.collision.shorttermencounter.probability.twod.Patera2005

All Implemented Interfaces:

ShortTermEncounter2DPOCMethod

public class Patera2005
extends AbstractShortTermEncounter1DNumerical2DPOCMethod

Compute the probability of collision using the method described in :"PATERA, Russell P. Calculating collision probability for arbitrary space vehicle shapes via numerical quadrature. Journal of guidance, control, and dynamics, 2005, vol. 28, no 6, p. 1326-1328.".

It is one of the recommended methods to use.

It assumes :

• Short encounter leading to a linear relative motion.
• Spherical collision object (in this implementation only. The method could be used on non spherical object).
• Uncorrelated positional covariance.
• Gaussian distribution of the position uncertainties.
• Deterministic velocity i.e. no velocity uncertainties.

It has been rewritten to use Orekit specific inputs.

Since:

12.0

Author:

Vincent Cucchietti

Field Summary

Fields inherited from class org.orekit.ssa.collision.shorttermencounter.probability.twod.AbstractShortTermEncounter2DPOCMethod

DEFAULT_TCA_DIFFERENCE_TOLERANCE

Fields inherited from interface org.orekit.ssa.collision.shorttermencounter.probability.twod.ShortTermEncounter2DPOCMethod

DEFAULT_ZERO_THRESHOLD

Constructor Summary

Constructors

Constructor and Description
Patera2005() Default constructor built with the following trapezoid integrator: Minimal iteration count of 5 Maximum iteration count of 50000 .
Patera2005(org.hipparchus.analysis.integration.UnivariateIntegrator integrator, int maxNbOfEval) Customizable constructor.

Method Summary

Modifier and Type	Method and Description
ProbabilityOfCollision	compute(double xm, double ym, double sigmaX, double sigmaY, double radius, org.hipparchus.analysis.integration.UnivariateIntegrator integrator, int customMaxNbOfEval) Compute the probability of collision using arguments specific to the rotated encounter frame and custom numerical configuration.
<T extends org.hipparchus.CalculusFieldElement<T>> FieldProbabilityOfCollision<T>	compute(T xm, T ym, T sigmaX, T sigmaY, T radius, org.hipparchus.analysis.integration.FieldUnivariateIntegrator<T> customIntegrator, int customMaxNbOfEval) Compute the probability of collision using arguments specific to the rotated encounter frame and custom numerical configuration.
ShortTermEncounter2DPOCMethodType	getType() Get type of the method.

Methods inherited from class org.orekit.ssa.collision.shorttermencounter.probability.twod.AbstractShortTermEncounter1DNumerical2DPOCMethod

compute, compute, compute, compute, compute, compute, compute, compute

Methods inherited from class org.orekit.ssa.collision.shorttermencounter.probability.twod.AbstractShortTermEncounter2DPOCMethod

compute, compute, compute, compute, compute, compute, getName, getObjectOrbitFromCdm, getObjectStateCovarianceFromCdm, isAMaximumProbabilityOfCollisionMethod

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.orekit.ssa.collision.shorttermencounter.probability.twod.ShortTermEncounter2DPOCMethod

compute, compute, compute, compute, compute, compute, compute, compute, compute

Constructor Detail

Patera2005

public Patera2005()

Default constructor built with the following trapezoid integrator:

• Minimal iteration count of 5
• Maximum iteration count of 50000

.

Patera2005

public Patera2005(org.hipparchus.analysis.integration.UnivariateIntegrator integrator,
                  int maxNbOfEval)

Customizable constructor.

Parameters:

integrator - integrator

maxNbOfEval - max number of evaluation

Method Detail

compute

public ProbabilityOfCollision compute(double xm,
                                      double ym,
                                      double sigmaX,
                                      double sigmaY,
                                      double radius,
                                      org.hipparchus.analysis.integration.UnivariateIntegrator integrator,
                                      int customMaxNbOfEval)

Compute the probability of collision using arguments specific to the rotated encounter frame and custom numerical configuration.

The rotated encounter frame is define by the initial encounter frame (defined in ShortTermEncounter2DDefinition) rotated by the rotation matrix which is used to diagonalize the combined covariance matrix.

Specified by:

compute in class AbstractShortTermEncounter1DNumerical2DPOCMethod

Parameters:

xm - other collision object projected position onto the collision plane in the rotated encounter frame x-axis (m)

ym - other collision object projected position onto the collision plane in the rotated encounter frame y-axis (m)

sigmaX - square root of the x-axis eigen value of the diagonalized combined covariance matrix projected onto the collision plane (m)

sigmaY - square root of the y-axis eigen value of the diagonalized combined covariance matrix projected onto the collision plane (m)

radius - sum of primary and secondary collision object equivalent sphere radii (m)

integrator - custom integrator to use in place of the integrator from the constructor

customMaxNbOfEval - custom maximum number of evaluations to use in place of the custom maximum number from the constructor

Returns:

probability of collision

compute

public <T extends org.hipparchus.CalculusFieldElement<T>> FieldProbabilityOfCollision<T> compute(T xm,
                                                                                                 T ym,
                                                                                                 T sigmaX,
                                                                                                 T sigmaY,
                                                                                                 T radius,
                                                                                                 org.hipparchus.analysis.integration.FieldUnivariateIntegrator<T> customIntegrator,
                                                                                                 int customMaxNbOfEval)

Compute the probability of collision using arguments specific to the rotated encounter frame and custom numerical configuration.

The rotated encounter frame is define by the initial encounter frame (defined in ShortTermEncounter2DDefinition) rotated by the rotation matrix which is used to diagonalize the combined covariance matrix.

Specified by:

compute in class AbstractShortTermEncounter1DNumerical2DPOCMethod

Type Parameters:

T - type of the field element

Parameters:

xm - other collision object projected position onto the collision plane in the rotated encounter frame x-axis (m)

ym - other collision object projected position onto the collision plane in the rotated encounter frame y-axis (m)

sigmaX - square root of the x-axis eigen value of the diagonalized combined covariance matrix projected onto the collision plane (m)

sigmaY - square root of the y-axis eigen value of the diagonalized combined covariance matrix projected onto the collision plane (m)

radius - sum of primary and secondary collision object equivalent sphere radii (m)

customIntegrator - custom integrator to use in place of the integrator from the constructor

customMaxNbOfEval - custom maximum number of evaluations to use in place of the custom maximum number from the constructor

Returns:

probability of collision

getType

public ShortTermEncounter2DPOCMethodType getType()

Get type of the method.

Returns:

type of the method