Package org.orekit.models.earth.ionosphere.nequick

Class NeQuickModel

java.lang.Object

org.orekit.models.earth.ionosphere.nequick.NeQuickModel

All Implemented Interfaces:

IonosphericModel, ParameterDriversProvider

Direct Known Subclasses:

NeQuickGalileo, NeQuickItu

public abstract class NeQuickModel
extends Object
implements IonosphericModel

NeQuick ionospheric delay model.

Since:

10.1

Author:

Bryan Cazabonne

See Also:

"European Union (2016). European GNSS (Galileo) Open Service-Ionospheric Correction Algorithm for Galileo Single Frequency Users. 1.2.", ITU-R P.531

Field Summary

Fields

Modifier and Type	Field	Description
static double	RE	Mean Earth radius in m (Ref Table 2.5.2).

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	NeQuickModel(TimeScale utc)	Simple constructor.

Method Summary

Modifier and Type	Method	Description
protected double	clipExp(double power)	A clipped exponential function.
protected <T extends CalculusFieldElement<T>> T	clipExp(T power)	A clipped exponential function.
protected abstract double	computeMODIP(double latitude, double longitude)	Compute modip for a location.
protected abstract <T extends CalculusFieldElement<T>> T	computeMODIP(T latitude, T longitude)	Compute modip for a location.
double	electronDensity(DateTimeComponents dateTime, double az, double latitude, double longitude, double h)	Computes the electron density at a given height.
<T extends CalculusFieldElement<T>> T	electronDensity(DateTimeComponents dateTime, T az, T latitude, T longitude, T h)	Computes the electron density at a given height.
List<ParameterDriver>	getParametersDrivers()	Get the drivers for parameters.
TimeScale	getUtc()	Get UTC time scale.
<T extends CalculusFieldElement<T>> T	pathDelay(FieldSpacecraftState<T> state, TopocentricFrame baseFrame, double frequency, T[] parameters)	Calculates the ionospheric path delay for the signal path from a ground station to a satellite.
double	pathDelay(SpacecraftState state, TopocentricFrame baseFrame, double frequency, double[] parameters)	Calculates the ionospheric path delay for the signal path from a ground station to a satellite.
double	stec(AbsoluteDate date, GeodeticPoint recP, GeodeticPoint satP)	This method allows the computation of the Slant Total Electron Content (STEC).
<T extends CalculusFieldElement<T>> T	stec(FieldAbsoluteDate<T> date, FieldGeodeticPoint<T> recP, FieldGeodeticPoint<T> satP)	This method allows the computation of the Slant Total Electron Content (STEC).

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.orekit.utils.ParameterDriversProvider

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

Field Detail

RE

public static final double RE

Mean Earth radius in m (Ref Table 2.5.2).

See Also:

Constant Field Values

Constructor Detail

NeQuickModel

protected NeQuickModel(TimeScale utc)

Simple constructor.

Parameters:

utc - UTC time scale

Since:

13.0

Method Detail

getUtc

public TimeScale getUtc()

Get UTC time scale.

Returns:

UTC time scale

Since:

13.0

pathDelay

public double pathDelay(SpacecraftState state,
                        TopocentricFrame baseFrame,
                        double frequency,
                        double[] parameters)

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

Specified by:

pathDelay in interface IonosphericModel

Parameters:

state - spacecraft state

baseFrame - base frame associated with the station

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(FieldSpacecraftState<T> state,
                                                       TopocentricFrame baseFrame,
                                                       double frequency,
                                                       T[] parameters)

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

Specified by:

pathDelay in interface IonosphericModel

Type Parameters:

T - type of the elements

Parameters:

state - spacecraft state

baseFrame - base frame associated with the station

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.

Specified by:

getParametersDrivers in interface ParameterDriversProvider

Returns:

drivers for parameters

stec

public double stec(AbsoluteDate date,
                   GeodeticPoint recP,
                   GeodeticPoint satP)

This method allows the computation of the Slant Total Electron Content (STEC).

Parameters:

date - current date

recP - receiver position

satP - satellite position

Returns:

the STEC in TECUnits

stec

public <T extends CalculusFieldElement<T>> T stec(FieldAbsoluteDate<T> date,
                                                  FieldGeodeticPoint<T> recP,
                                                  FieldGeodeticPoint<T> satP)

This method allows the computation of the Slant Total Electron Content (STEC).

Type Parameters:

T - type of the elements

Parameters:

date - current date

recP - receiver position

satP - satellite position

Returns:

the STEC in TECUnits

computeMODIP

protected abstract double computeMODIP(double latitude,
                                       double longitude)

Compute modip for a location.

Parameters:

latitude - latitude

longitude - longitude

Returns:

modip at specified location

Since:

13.0

computeMODIP

protected abstract <T extends CalculusFieldElement<T>> T computeMODIP(T latitude,
                                                                      T longitude)

Compute modip for a location.

Type Parameters:

T - type of the field elements

Parameters:

latitude - latitude

longitude - longitude

Returns:

modip at specified location

Since:

13.0

electronDensity

public double electronDensity(DateTimeComponents dateTime,
                              double az,
                              double latitude,
                              double longitude,
                              double h)

Computes the electron density at a given height.

Parameters:

dateTime - date

az - effective ionization level

latitude - latitude along the integration path

longitude - longitude along the integration path

h - height along the integration path in m

Returns:

electron density [m⁻³]

Since:

13.0

electronDensity

public <T extends CalculusFieldElement<T>> T electronDensity(DateTimeComponents dateTime,
                                                             T az,
                                                             T latitude,
                                                             T longitude,
                                                             T h)

Computes the electron density at a given height.

Type Parameters:

T - type of the elements

Parameters:

dateTime - date

az - effective ionization level

latitude - latitude along the integration path

longitude - longitude along the integration path

h - height along the integration path in m

Returns:

electron density [m⁻³]

Since:

13.0

clipExp

protected double clipExp(double power)

A clipped exponential function.

This function, describe in section F.2.12.2 of the reference document, is recommended for the computation of exponential values.

Parameters:

power - power for exponential function

Returns:

clipped exponential value

clipExp

protected <T extends CalculusFieldElement<T>> T clipExp(T power)

A clipped exponential function.

This function, describe in section F.2.12.2 of the reference document, is recommended for the computation of exponential values.

Type Parameters:

T - type of the elements

Parameters:

power - power for exponential function

Returns:

clipped exponential value