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

Class 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:
    Mahalanobis distance.

    • Constructor Detail

      • Alfriend1999Max

        public Alfriend1999Max()
        Empty constructor.

    • Method Detail

      • 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