org.orekit.propagation.semianalytical.dsst.utilities.hansen

Class FieldHansenThirdBodyLinear<T extends RealFieldElement<T>>

java.lang.Object

org.orekit.propagation.semianalytical.dsst.utilities.hansen.FieldHansenThirdBodyLinear<T>

public class FieldHansenThirdBodyLinear<T extends RealFieldElement<T>>
extends Object

Hansen coefficients K(t,n,s) for t=0 and n > 0.

Implements Collins 4-254 or Danielson 2.7.3-(7) for Hansen Coefficients and Danielson 3.2-(3) for derivatives. The recursions are transformed into composition of linear transformations to obtain the associated polynomials for coefficients and their derivatives - see Petre's paper

Author:

Petre Bazavan, Lucian Barbulescu, Bryan Cazabonne

Constructor Summary

Constructors

Constructor and Description
FieldHansenThirdBodyLinear(int nMax, int s, Field<T> field) Constructor.

Method Summary

Modifier and Type	Method and Description
void	computeInitValues(T chitm1, T chitm2, T chitm3) Compute the initial values (see Collins, 4-255, 4-256 and 4.259)
T	getDerivative(int n, T chitm1) Compute the value of the Hansen coefficient dK₀n, s / dΧ.
T	getValue(int n, T chitm1) Compute the value of the Hansen coefficient K₀n, s.

Methods inherited from class java.lang.Object

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

Constructor Detail

FieldHansenThirdBodyLinear

public FieldHansenThirdBodyLinear(int nMax,
                                  int s,
                                  Field<T> field)

Constructor.

Parameters:

nMax - the maximum value of n

s - the value of s

field - field used by default

Method Detail

computeInitValues

public void computeInitValues(T chitm1,
                              T chitm2,
                              T chitm3)

Compute the initial values (see Collins, 4-255, 4-256 and 4.259)

K₀^{s, s} = (-1)^s * ( (2*s+1)!! / (s+1)! )

K₀^{s+1, s} = (-1)^s * ( (2*s+1)!! / (s+2)! ) * (2*s+3 - χ^-2)

dK₀^{s+1, s} / dχ = = (-1)^s * 2 * ( (2*s+1)!! / (s+2)! ) * χ^-3

Parameters:

chitm1 - sqrt(1 - e²)

chitm2 - sqrt(1 - e²)²

chitm3 - sqrt(1 - e²)³

getValue

public T getValue(int n,
                  T chitm1)

Compute the value of the Hansen coefficient K₀^{n, s}.

Parameters:

n - n value

chitm1 - χ^-1

Returns:

the coefficient K₀^{n, s}

getDerivative

public T getDerivative(int n,
                       T chitm1)

Compute the value of the Hansen coefficient dK₀^{n, s} / dΧ.

Parameters:

n - n value

chitm1 - χ^-1

Returns:

the coefficient dK₀^{n, s} / dΧ