Package 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

  • Constructor Details

    • Patera2005

      public Patera2005()
      Default constructor built with the following trapezoid integrator:
      • Minimal iteration count of 5
      • Maximum iteration count of 50000
      .

    • Patera2005

      public Patera2005(UnivariateIntegrator integrator, int maxNbOfEval)
      Customizable constructor.
      Parameters:
      integrator - integrator
      maxNbOfEval - max number of evaluation

  • Method Details

    • compute

      public ProbabilityOfCollision compute(double xm, double ym, double sigmaX, double sigmaY, double radius, 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 CalculusFieldElement<T>> FieldProbabilityOfCollision<T> compute(T xm, T ym, T sigmaX, T sigmaY, T radius, 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