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

Class Alfriend1999Max

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.Alfriend1999Max
All Implemented Interfaces:
ShortTermEncounter2DPOCMethod
public class Alfriend1999Max extends AbstractAlfriend1999
Compute the probability of collision assuming the worst case 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 circle (eq 18).
  • Covariance multiplied by a coefficient KSquared = MahalanobisDistanceSquared / 2 (eq 19-20).

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
See Also:

  • Constructor Details

    • Alfriend1999Max

      public Alfriend1999Max()
      Empty constructor.

  • Method Details

    • computeValue

      public double computeValue(double radius, double squaredMahalanobisDistance, double covarianceMatrixDeterminant)
      Compute the value of the probability of collision.
      Parameters:
      radius - sum of primary and secondary collision object equivalent sphere radii (m)
      squaredMahalanobisDistance - squared Mahalanobis distance
      covarianceMatrixDeterminant - covariance matrix determinant
      Returns:
      value of the probability of collision

    • computeValue

      public <T extends CalculusFieldElement<T>> T computeValue(T radius, T squaredMahalanobisDistance, T covarianceMatrixDeterminant)
      Compute the value of the probability of collision.
      Type Parameters:
      T - type of the field elements
      Parameters:
      radius - sum of primary and secondary collision object equivalent sphere radii (m)
      squaredMahalanobisDistance - squared Mahalanobis distance
      covarianceMatrixDeterminant - covariance matrix determinant
      Returns:
      value of the probability of collision

    • 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