Package org.orekit.models.earth.ionosphere

Class EstimatedIonosphericModel

java.lang.Object

org.orekit.models.earth.ionosphere.AbstractIonosphericModel

org.orekit.models.earth.ionosphere.EstimatedIonosphericModel

All Implemented Interfaces:

IonosphericModel, ParameterDriversProvider

public class EstimatedIonosphericModel
extends AbstractIonosphericModel

An estimated ionospheric model. The ionospheric delay is computed according to the formula:

40.3 δ = -------- * STEC with, STEC = VTEC * F(elevation) f²

With:

• f: The frequency of the signal in Hz.
• STEC: The Slant Total Electron Content in TECUnits.
• VTEC: The Vertical Total Electron Content in TECUnits.
• F(elevation): A mapping function which depends on satellite elevation.

The VTEC is estimated as a ParameterDriver

Since:

10.2

Author:

Bryan Cazabonne

Nested Class Summary

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

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

Field Summary

Fields

Modifier and Type	Field	Description
static String	VERTICAL_TOTAL_ELECTRON_CONTENT	Name of the parameter of this model: the Vertical Total Electron Content.

Constructor Summary

Constructors

Constructor	Description
EstimatedIonosphericModel(OneAxisEllipsoid earth, IonosphericMappingFunction model, double vtecValue)	Build a new instance.

Method Summary

Modifier and Type	Method	Description
List<ParameterDriver>	getParametersDrivers()	Get the drivers for parameters.
double	pathDelay(double elevation, double frequency, double[] parameters)	Calculates the ionospheric path delay for the signal path from a ground station to a satellite.
<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).
<T extends CalculusFieldElement<T>> T	pathDelay(T elevation, double frequency, T[] parameters)	Calculates the ionospheric path delay for the signal path from a ground station to a 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

Field Detail

VERTICAL_TOTAL_ELECTRON_CONTENT

public static final String VERTICAL_TOTAL_ELECTRON_CONTENT

Name of the parameter of this model: the Vertical Total Electron Content.

See Also:

Constant Field Values

Constructor Detail

EstimatedIonosphericModel

public EstimatedIonosphericModel(OneAxisEllipsoid earth,
                                 IonosphericMappingFunction model,
                                 double vtecValue)

Build a new instance.

Parameters:

earth - earth body shape

model - ionospheric mapping function

vtecValue - value of the Vertical Total Electron Content in TECUnits

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 double pathDelay(double elevation,
                        double frequency,
                        double[] parameters)

Calculates the ionospheric path delay for the signal path from a ground station to a satellite.

The path delay is computed for any elevation angle.

Parameters:

elevation - elevation of the satellite in radians

frequency - frequency of the signal in Hz

parameters - ionospheric model parameters

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

pathDelay

public <T extends CalculusFieldElement<T>> T pathDelay(T elevation,
                                                       double frequency,
                                                       T[] parameters)

Calculates the ionospheric path delay for the signal path from a ground station to a satellite.

The path delay is computed for any elevation angle.

Type Parameters:

T - type of the elements

Parameters:

elevation - elevation of the satellite in radians

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()

Description copied from interface: ParameterDriversProvider

Get the drivers for parameters.

Returns:

drivers for parameters