AbstractRelativisticClockModifier.java
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package org.orekit.estimation.measurements.modifiers;
import org.hipparchus.geometry.euclidean.threed.Vector3D;
import org.orekit.estimation.measurements.EstimatedMeasurement;
import org.orekit.utils.Constants;
import org.orekit.utils.TimeStampedPVCoordinates;
/** Class modifying theoretical measurements with relativistic clock correction.
* <p>
* Relativistic clock correction is caused by the motion of the satellite as well as
* the change in the gravitational potential
* </p>
* @author Bryan Cazabonne
* @since 10.3
*
* @see "Teunissen, Peter, and Oliver Montenbruck, eds. Springer handbook of global navigation
* satellite systems. Chapter 19.2. Springer, 2017."
*/
public class AbstractRelativisticClockModifier {
/** Relativistic effect scale factor. */
private final double s;
/** Simple constructor. */
public AbstractRelativisticClockModifier() {
this.s = -2.0 / (Constants.SPEED_OF_LIGHT * Constants.SPEED_OF_LIGHT);
}
/** Computes the relativistic clock correction.
* @param estimated estimated measurement
* @return the relativistic clock correction in seconds
*/
protected double relativisticCorrection(final EstimatedMeasurement<?> estimated) {
// Participants
final TimeStampedPVCoordinates[] pv = estimated.getParticipants();
// Relativistic clock correction taking into account two-ways measurements
return pv.length < 3 ?
s * (dotProduct(pv[0]) - dotProduct(pv[1])) :
s * (dotProduct(pv[1]) - dotProduct(pv[2]));
}
/** Get the scale factor used to compute relativistic effect.
* @return the scale factor
*/
protected double getScaleFactor() {
return s;
}
/** Compute the dot-product of position and velocity vectors.
* @param pv satellite coordinates
* @return the dot-product of position and velocity vectors
*/
private static double dotProduct(final TimeStampedPVCoordinates pv) {
return Vector3D.dotProduct(pv.getPosition(), pv.getVelocity());
}
}