org.orekit.orbits
Class CartesianOrbit

java.lang.Object
  org.orekit.orbits.Orbit
      org.orekit.orbits.CartesianOrbit

All Implemented Interfaces:

java.io.Serializable, TimeStamped

public class CartesianOrbit
extends Orbit

This class holds cartesian orbital parameters.

The parameters used internally are the cartesian coordinates:

• x
• y
• z
• xDot
• yDot
• zDot

contained in PVCoordinates.

Note that the implementation of this class delegates all non-cartesian related computations (getA(), getEquinoctialEx(), ...) to an underlying instance of the EquinoctialOrbit class. This implies that using this class only for analytical computations which are always based on non-cartesian parameters is perfectly possible but somewhat sub-optimal.

The instance CartesianOrbit is guaranteed to be immutable.

Version:

$Revision:1665 $ $Date:2008-06-11 12:12:59 +0200 (mer., 11 juin 2008) $

Author:

Luc Maisonobe, Guylaine Prat, Fabien Maussion, Véronique Pommier-Maurussane

See Also:

Orbit, KeplerianOrbit, CircularOrbit, EquinoctialOrbit, Serialized Form

Constructor Summary

CartesianOrbit(Orbit op)
Constructor from any kind of orbital parameters.

CartesianOrbit(PVCoordinates pvCoordinates, Frame frame, AbsoluteDate date, double mu)
Constructor from cartesian parameters.

Method Summary

double	getA() Get the semi-major axis.
double	getE() Get the eccentricity.
double	getEquinoctialEx() Get the first component of the eccentricity vector.
double	getEquinoctialEy() Get the second component of the eccentricity vector.
double	getHx() Get the first component of the inclination vector.
double	getHy() Get the second component of the inclination vector.
double	getI() Get the inclination.
double	getLE() Get the eccentric latitude argument.
double	getLM() Get the mean latitude argument.
double	getLv() Get the true latitude argument.
CartesianOrbit	shiftedBy(double dt) Get a time-shifted orbit.
java.lang.String	toString() Returns a string representation of this Orbit object.

Methods inherited from class org.orekit.orbits.Orbit

getDate, getFrame, getKeplerianMeanMotion, getKeplerianPeriod, getMu, getPVCoordinates, getPVCoordinates

Methods inherited from class java.lang.Object

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

Constructor Detail

CartesianOrbit

public CartesianOrbit(PVCoordinates pvCoordinates,
                      Frame frame,
                      AbsoluteDate date,
                      double mu)
               throws java.lang.IllegalArgumentException

Constructor from cartesian parameters.

Parameters:

pvCoordinates - the position and velocity of the satellite.

frame - the frame in which the PVCoordinates are defined (must be a quasi-inertial frame)

date - date of the orbital parameters

mu - central attraction coefficient (m³/s²)

Throws:

java.lang.IllegalArgumentException - if frame is not a quasi-inertial frame

CartesianOrbit

public CartesianOrbit(Orbit op)

Constructor from any kind of orbital parameters.

Parameters:

op - orbital parameters to copy

Method Detail

getA

public double getA()

Get the semi-major axis.

Specified by:

getA in class Orbit

Returns:

semi-major axis (m)

getE

public double getE()

Get the eccentricity.

Specified by:

getE in class Orbit

Returns:

eccentricity

getI

public double getI()

Get the inclination.

Specified by:

getI in class Orbit

Returns:

inclination (rad)

getEquinoctialEx

public double getEquinoctialEx()

Get the first component of the eccentricity vector.

Specified by:

getEquinoctialEx in class Orbit

Returns:

first component of the eccentricity vector

getEquinoctialEy

public double getEquinoctialEy()

Get the second component of the eccentricity vector.

Specified by:

getEquinoctialEy in class Orbit

Returns:

second component of the eccentricity vector

getHx

public double getHx()

Get the first component of the inclination vector.

Specified by:

getHx in class Orbit

Returns:

first component of the inclination vector.

getHy

public double getHy()

Get the second component of the inclination vector.

Specified by:

getHy in class Orbit

Returns:

second component of the inclination vector.

getLv

public double getLv()

Get the true latitude argument.

Specified by:

getLv in class Orbit

Returns:

true latitude argument (rad)

getLE

public double getLE()

Get the eccentric latitude argument.

Specified by:

getLE in class Orbit

Returns:

eccentric latitude argument.(rad)

getLM

public double getLM()

Get the mean latitude argument.

Specified by:

getLM in class Orbit

Returns:

mean latitude argument.(rad)

shiftedBy

public CartesianOrbit shiftedBy(double dt)

Get a time-shifted orbit.

The orbit can be slightly shifted to close dates. This shift is based on a simple keplerian model. It is not intended as a replacement for proper orbit and attitude propagation but should be sufficient for small time shifts or coarse accuracy.

Specified by:

shiftedBy in class Orbit

Parameters:

dt - time shift in seconds

Returns:

a new orbit, shifted with respect to the instance (which is immutable)

See Also:

AbsoluteDate.shiftedBy(double), PVCoordinates.shiftedBy(double), Attitude.shiftedBy(double), SpacecraftState.shiftedBy(double)

toString

public java.lang.String toString()

Returns a string representation of this Orbit object.

Overrides:

toString in class java.lang.Object

Returns:

a string representation of this object