org.jeospace.physics.orbit
Class SxP4EllipticMotion

java.lang.Object
  org.jeospace.physics.orbit.SxP4EllipticMotion

All Implemented Interfaces:

EllipticMotion

public class SxP4EllipticMotion

extends java.lang.Object

implements EllipticMotion

Implements the SGP4/SDP4 models for elliptic motion of satellites in Earth orbit. The SGP4 model is designed to predict the motion of satellites in low Earth orbit and to compensate for environmental effects such as atmospheric drag. The SDP4 model is designed to predict the motion of high Earth orbit satellites and to additionally compensate for the gravitational effects of the Moon and the Sun.

The orbital elements of satellites which function properly with these algorithms are obtained from "NORAD Two-Line Element Sets". TLE's and much more can be found at: http://www.celestrak.com/.

The original algorithms (in Fortran) are found in Spacetrack Report No. 3, Models for Propogation of NORAD Element sets. A copy can be found at: http://www.celestrak.com/NORAD/documentation/spacetrk.pdf.

Version:

$Revision: 1.1.1.1 $

Author:

Rex Melton

See Also:

OrbitalElements, Cartesian, Spherical

Nested Class Summary

protected class

SxP4EllipticMotion.SDP4

Constructor Summary

SxP4EllipticMotion(OrbitalElements oe)
Construct an instance

Method Summary

void	getValue(double julianDay, Cartesian position) Return the position of the satellite for the given Julian day in the passed Cartesian object.
void	getValue(double julianDay, Spherical spherical) Return the position of the satellite for the given Julian Day in the passed Spherical object.
void	set(OrbitalElements oe) Set the value of the orbital elements and element dependant variables used in the calculation of the satellite's elliptic motion

Methods inherited from class java.lang.Object

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

Constructor Detail

SxP4EllipticMotion

public SxP4EllipticMotion(OrbitalElements oe)

Construct an instance

Parameters:

oe - the OrbitalElements of the satellite

Method Detail

set

public void set(OrbitalElements oe)

Set the value of the orbital elements and element dependant variables used in the calculation of the satellite's elliptic motion

Specified by:

set in interface EllipticMotion

Parameters:

oe - the OrbitalElements of the satellite

getValue

public void getValue(double julianDay,
                     Spherical spherical)

Return the position of the satellite for the given Julian Day in the passed Spherical object.

Specified by:

getValue in interface EllipticMotion

Parameters:

julianDay - the Julian day

spherical - the Spherical object to initialize with the satellite's position

getValue

public void getValue(double julianDay,
                     Cartesian position)

Return the position of the satellite for the given Julian day in the passed Cartesian object.

Specified by:

getValue in interface EllipticMotion

Parameters:

julianDay - the Julian day

position - the Cartesian object to initialize with the satellite's position