AbstractGaussianContributionContext.java
/* Copyright 2002-2022 CS GROUP
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* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* CS licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
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package org.orekit.propagation.semianalytical.dsst.forces;
import org.hipparchus.util.FastMath;
import org.orekit.propagation.semianalytical.dsst.utilities.AuxiliaryElements;
/**
* This class is a container for the common parameters used in {@link AbstractGaussianContribution}.
* <p>
* It performs parameters initialization at each integration step for the Gaussian contributions
* </p>
* @author Bryan Cazabonne
* @since 10.0
*/
public class AbstractGaussianContributionContext extends ForceModelContext {
// CHECKSTYLE: stop VisibilityModifier check
/** 2 / (n² * a) . */
protected double ton2a;
/** 1 / A . */
protected double ooA;
/** 1 / (A * B) . */
protected double ooAB;
/** C / (2 * A * B) . */
protected double co2AB;
/** 1 / (1 + B) . */
protected double ooBpo;
/** 1 / μ . */
protected double ooMu;
/** A = sqrt(μ * a). */
private final double A;
/** Keplerian mean motion. */
private final double n;
/** Central attraction coefficient. */
private double mu;
// CHECKSTYLE: resume VisibilityModifier check
/**
* Simple constructor.
*
* @param auxiliaryElements auxiliary elements related to the current orbit
* @param parameters parameters values of the force model parameters
*/
AbstractGaussianContributionContext(final AuxiliaryElements auxiliaryElements, final double[] parameters) {
super(auxiliaryElements);
// mu driver corresponds to the last term of parameters driver array
mu = parameters[parameters.length - 1];
// Keplerian Mean Motion
final double absA = FastMath.abs(auxiliaryElements.getSma());
n = FastMath.sqrt(mu / absA) / absA;
// sqrt(μ * a)
A = FastMath.sqrt(mu * auxiliaryElements.getSma());
// 1 / A
ooA = 1. / A;
// 1 / AB
ooAB = ooA / auxiliaryElements.getB();
// C / 2AB
co2AB = auxiliaryElements.getC() * ooAB / 2.;
// 1 / (1 + B)
ooBpo = 1. / (1. + auxiliaryElements.getB());
// 2 / (n² * a)
ton2a = 2. / (n * n * auxiliaryElements.getSma());
// 1 / mu
ooMu = 1. / mu;
}
/** Get central attraction coefficient.
* @return mu
*/
public double getMu() {
return mu;
}
/** Get ooA = 1 / A.
* @return ooA
*/
public double getOOA() {
return ooA;
}
/** Get ooAB = 1 / (A * B).
* @return ooAB
*/
public double getOOAB() {
return ooAB;
}
/** Get co2AB = C / 2AB.
* @return co2AB
*/
public double getCo2AB() {
return co2AB;
}
/** Get ooBpo = 1 / (B + 1).
* @return ooBpo
*/
public double getOoBpo() {
return ooBpo;
}
/** Get ton2a = 2 / (n² * a).
* @return ton2a
*/
public double getTon2a() {
return ton2a;
}
/** Get ooMu = 1 / mu.
* @return ooMu
*/
public double getOoMU() {
return ooMu;
}
/** Get the Keplerian mean motion.
* <p>The Keplerian mean motion is computed directly from semi major axis
* and central acceleration constant.</p>
* @return Keplerian mean motion in radians per second
*/
public double getMeanMotion() {
return n;
}
}