StationDisplacement
public class TidalDisplacement extends Object implements StationDisplacement
This class implements displacement of reference point (i.e.
ground stations
)
due to tidal effects, as per IERS conventions.
Displacement can be computed with respect to either conventional tide free or mean tide coordinates. The difference between the two systems is about -12cm at poles and +6cm at equator. Selecting one system or the other depends on how the station coordinates have been computed (i.e. it depends whether the coordinates already include the permanent deformation or not).
Instances of this class are guaranteed to be immutable
GroundStation
Constructor | Description |
---|---|
TidalDisplacement(double rEarth,
double sunEarthSystemMassRatio,
double earthMoonMassRatio,
PVCoordinatesProvider sun,
PVCoordinatesProvider moon,
IERSConventions conventions,
boolean removePermanentDeformation) |
Simple constructor.
|
Modifier and Type | Method | Description |
---|---|---|
Vector3D |
displacement(BodiesElements elements,
Frame earthFrame,
Vector3D referencePoint) |
Compute displacement of a ground reference point.
|
public TidalDisplacement(double rEarth, double sunEarthSystemMassRatio, double earthMoonMassRatio, PVCoordinatesProvider sun, PVCoordinatesProvider moon, IERSConventions conventions, boolean removePermanentDeformation) throws OrekitException
rEarth
- Earth equatorial radius (from gravity field model)sunEarthSystemMassRatio
- Sun/(Earth + Moon) mass ratio
(typically Constants.JPL_SSD_SUN_EARTH_PLUS_MOON_MASS_RATIO
)earthMoonMassRatio
- Earth/Moon mass ratio
(typically Constants.JPL_SSD_EARTH_MOON_MASS_RATIO
)sun
- Sun modelmoon
- Moon modelconventions
- IERS conventions to useremovePermanentDeformation
- if true, the station coordinates are
considered mean tide and already include the permanent deformation, hence
it should be removed from the displacement to avoid considering it twice;
if false, the station coordinates are considered conventional tide free
so the permanent deformation must be included in the displacementOrekitException
- if fundamental nutation arguments cannot be loadedFramesFactory.getITRF(IERSConventions, boolean)
,
FramesFactory.getEOPHistory(IERSConventions, boolean)
,
Constants.JPL_SSD_SUN_EARTH_PLUS_MOON_MASS_RATIO
,
Constants.JPL_SSD_EARTH_MOON_MASS_RATIO
public Vector3D displacement(BodiesElements elements, Frame earthFrame, Vector3D referencePoint) throws OrekitException
displacement
in interface StationDisplacement
elements
- elements affecting Earth orientationearthFrame
- Earth frame in which reference point is definedreferencePoint
- reference point position in earthFrame
referencePoint
OrekitException
- if displacement cannot be computedCopyright © 2002-2018 CS Systèmes d'information. All rights reserved.