Package org.orekit.models.earth.ionosphere

Class SsrVtecIonosphericModel

java.lang.Object

org.orekit.models.earth.ionosphere.AbstractIonosphericModel

org.orekit.models.earth.ionosphere.SsrVtecIonosphericModel

All Implemented Interfaces:

IonosphericModel, ParameterDriversProvider

public class SsrVtecIonosphericModel
extends AbstractIonosphericModel

Ionospheric model based on SSR IM201 message.

Within this message, the ionospheric VTEC is provided using spherical harmonic expansions. For a given ionospheric layer, the slant TEC value is calculated using the satellite elevation and the height of the corresponding layer. The total slant TEC is computed by the sum of the individual slant TEC for each layer.

Since:

11.0

Author:

Bryan Cazabonne

See Also:

"IGS State Space Representation (SSR) Format, Version 1.00, October 2020."

Nested Class Summary

Nested classes/interfaces inherited from interface org.orekit.models.earth.ionosphere.IonosphericModel

IonosphericModel.DelayCalculator, IonosphericModel.FieldDelayCalculator<T extends CalculusFieldElement<T>>

Constructor Summary

Constructors

Constructor	Description
SsrVtecIonosphericModel(OneAxisEllipsoid earth, SsrIm201 vtecMessage)	Constructor.

Method Summary

Modifier and Type	Method	Description
List<ParameterDriver>	getParametersDrivers()	Get the drivers for parameters.
<T extends CalculusFieldElement<T>> T	pathDelay(FieldVector3D<T> localP1, FieldVector3D<T> localP2, TopocentricFrame baseFrame, FieldAbsoluteDate<T> receptionDate, double frequency, T[] parameters)	Calculates the ionospheric path delay for the signal path from a ground station to an observing object (ground station or satellite).
double	pathDelay(Vector3D localP1, Vector3D localP2, TopocentricFrame baseFrame, AbsoluteDate receptionDate, double frequency, double[] parameters)	Calculates the ionospheric path delay for the signal path from a ground station to an observing object (ground station or satellite).

Methods inherited from class org.orekit.models.earth.ionosphere.AbstractIonosphericModel

checkIfPathIsValid, checkIfPathIsValid, getEarth

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.orekit.models.earth.ionosphere.IonosphericModel

pathDelay, pathDelay

Methods inherited from interface org.orekit.utils.ParameterDriversProvider

getNbParametersDriversValue, getParameterDriver, getParameters, getParameters, getParameters, getParameters, getParametersAllValues, getParametersAllValues, isSupported

Constructor Detail

SsrVtecIonosphericModel

public SsrVtecIonosphericModel(OneAxisEllipsoid earth,
                               SsrIm201 vtecMessage)

Constructor.

Parameters:

earth - earth body shape

vtecMessage - SSR Ionosphere VTEC Spherical Harmonics Message.

Since:

14.0

Method Detail

pathDelay

public double pathDelay(Vector3D localP1,
                        Vector3D localP2,
                        TopocentricFrame baseFrame,
                        AbsoluteDate receptionDate,
                        double frequency,
                        double[] parameters)

Calculates the ionospheric path delay for the signal path from a ground station to an observing object (ground station or satellite).

This method is intended to be used for orbit determination issues. In that respect, if the elevation is below 0° the path delay will be equal to zero.

For individual use of the ionospheric model (i.e. not for orbit determination), another method signature can be implemented to compute the path delay for any elevation angle.

Parameters:

localP1 - position of path start point in baseFrame

localP2 - position of path end point in baseFrame

baseFrame - topocentric frame of point with lowest altitude between p1 and p2

receptionDate - date at signal reception

frequency - frequency of the signal in Hz

parameters - ionospheric model parameters at state date

Returns:

the path delay due to the ionosphere in m

pathDelay

public <T extends CalculusFieldElement<T>> T pathDelay(FieldVector3D<T> localP1,
                                                       FieldVector3D<T> localP2,
                                                       TopocentricFrame baseFrame,
                                                       FieldAbsoluteDate<T> receptionDate,
                                                       double frequency,
                                                       T[] parameters)

Calculates the ionospheric path delay for the signal path from a ground station to an observing object (ground station or satellite).

This method is intended to be used for orbit determination issues. In that respect, if the elevation is below 0° the path delay will be equal to zero.

For individual use of the ionospheric model (i.e. not for orbit determination), another method signature can be implemented to compute the path delay for any elevation angle.

Type Parameters:

T - type of the elements

Parameters:

localP1 - position of path start point in baseFrame

localP2 - position of path end point in baseFrame

baseFrame - topocentric frame of point with lowest altitude between p1 and p2

receptionDate - date at signal reception

frequency - frequency of the signal in Hz

parameters - ionospheric model parameters at state date

Returns:

the path delay due to the ionosphere in m

getParametersDrivers

public List<ParameterDriver> getParametersDrivers()

Get the drivers for parameters.

Returns:

drivers for parameters