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

Class HansenThirdBodyLinear

java.lang.Object

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

public class HansenThirdBodyLinear
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

Constructor Summary

Constructors

Constructor and Description
HansenThirdBodyLinear(int nMax, int s) Constructor.

Method Summary

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

HansenThirdBodyLinear

public HansenThirdBodyLinear(int nMax,
                             int s)

Constructor.

Parameters:

nMax - the maximum value of n

s - the value of s

Method Detail

computeInitValues

public void computeInitValues(double chitm1,
                              double chitm2,
                              double 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 double getValue(int n,
                       double 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 double getDerivative(int n,
                            double 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