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

Class Alfriend1999

java.lang.Object

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

org.orekit.ssa.collision.shorttermencounter.probability.twod.AbstractAlfriend1999

org.orekit.ssa.collision.shorttermencounter.probability.twod.Alfriend1999

All Implemented Interfaces:

ShortTermEncounter2DPOCMethod

public class Alfriend1999
extends AbstractAlfriend1999

Compute the probability of collision using the method described in : "Kyle Alfriend, Maruthi Akella, Joseph Frisbee, James Foster, Deok-Jin Lee, and Matthew Wilkins. Probability of ProbabilityOfCollision Error Analysis. Space Debris, 1(1):21–35, 1999.".

It assumes :

• Short encounter leading to a linear relative motion.
• Spherical collision object.
• Uncorrelated positional covariance.
• Gaussian distribution of the position uncertainties.
• Deterministic velocity i.e. no velocity uncertainties.
• Both objects are in circular orbits (eq 14).
• Probability density function is constant over the collision disk (eq 18).

By assuming a constant probability density function over the collision circle this method will, most of the time, give much higher probability of collision than other regular methods. That is why it is qualified as a maximum probability of collision computing method.

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	Description
Alfriend1999()	Empty constructor.

Method Summary

Modifier and Type	Method	Description
ShortTermEncounter2DPOCMethodType	getType()	Get type of the method.
boolean	isAMaximumProbabilityOfCollisionMethod()	Get flag that defines if the method is a maximum probability of collision computing method.

Methods inherited from class org.orekit.ssa.collision.shorttermencounter.probability.twod.AbstractAlfriend1999

compute, compute

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

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

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 Details

Alfriend1999

public Alfriend1999()

Empty constructor.

Method Details

isAMaximumProbabilityOfCollisionMethod

public boolean isAMaximumProbabilityOfCollisionMethod()

Get flag that defines if the method is a maximum probability of collision computing method.

Specified by:

isAMaximumProbabilityOfCollisionMethod in interface ShortTermEncounter2DPOCMethod

Overrides:

isAMaximumProbabilityOfCollisionMethod in class AbstractShortTermEncounter2DPOCMethod

Returns:

flag that defines if the method is a maximum probability of collision computing method

getType

public ShortTermEncounter2DPOCMethodType getType()

Get type of the method.

Returns:

type of the method