org.orekit.models.earth.troposphere

Class EstimatedTroposphericModel

java.lang.Object

org.orekit.models.earth.troposphere.EstimatedTroposphericModel

All Implemented Interfaces:

DiscreteTroposphericModel

public class EstimatedTroposphericModel
extends Object
implements DiscreteTroposphericModel

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

δ = δ_h * m_h + (δ_t - δ_h) * m_w

With:

• δ_h: Tropospheric zenith hydro-static delay.
• δ_t: Tropospheric total zenith delay.
• m_h: Hydro-static mapping function.
• m_w: Wet mapping function.

The mapping functions m_h(e) and m_w(e) are computed thanks to a model initialized by the user. The user has the possibility to use several mapping function models for the computations: the Global Mapping Function, or the Niell Mapping Function

The tropospheric zenith delay δ_h is computed empirically with a SaastamoinenModel while the tropospheric total zenith delay δ_t is estimated as a ParameterDriver

Field Summary

Fields

Modifier and Type	Field and Description
static String	TOTAL_ZENITH_DELAY Name of the parameter of this model: the total zenith delay.

Constructor Summary

Constructors

Constructor and Description
EstimatedTroposphericModel(double t0, double p0, MappingFunction model, double totalDelay) Build a new instance using the given environmental conditions.
EstimatedTroposphericModel(MappingFunction model, double totalDelay) Build a new instance using a standard atmosphere model.

Method Summary

Modifier and Type	Method and Description
List<ParameterDriver>	getParametersDrivers() Get the drivers for tropospheric model parameters.
double	pathDelay(double elevation, GeodeticPoint point, double[] parameters, AbsoluteDate date) Calculates the tropospheric path delay for the signal path from a ground station to a satellite.
<T extends CalculusFieldElement<T>> T	pathDelay(T elevation, FieldGeodeticPoint<T> point, T[] parameters, FieldAbsoluteDate<T> date) Calculates the tropospheric path delay for the signal path from a ground station to a satellite.

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.troposphere.DiscreteTroposphericModel

getParameters, getParameters

Field Detail

TOTAL_ZENITH_DELAY

public static final String TOTAL_ZENITH_DELAY

Name of the parameter of this model: the total zenith delay.

See Also:

Constant Field Values

Constructor Detail

EstimatedTroposphericModel

public EstimatedTroposphericModel(double t0,
                                  double p0,
                                  MappingFunction model,
                                  double totalDelay)

Build a new instance using the given environmental conditions.

Parameters:

t0 - the temperature at the station [K]

p0 - the atmospheric pressure at the station [mbar]

model - mapping function model (NMF or GMF).

totalDelay - initial value for the tropospheric zenith total delay [m]

EstimatedTroposphericModel

public EstimatedTroposphericModel(MappingFunction model,
                                  double totalDelay)

Build a new instance using a standard atmosphere model.

• temperature: 18 degree Celsius
• pressure: 1013.25 mbar

Parameters:

model - mapping function model (NMF or GMF).

totalDelay - initial value for the tropospheric zenith total delay [m]

Method Detail

getParametersDrivers

public List<ParameterDriver> getParametersDrivers()

Get the drivers for tropospheric model parameters.

Specified by:

getParametersDrivers in interface DiscreteTroposphericModel

Returns:

drivers for tropospheric model parameters

pathDelay

public double pathDelay(double elevation,
                        GeodeticPoint point,
                        double[] parameters,
                        AbsoluteDate date)

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

Specified by:

pathDelay in interface DiscreteTroposphericModel

Parameters:

elevation - the elevation of the satellite, in radians

point - station location

parameters - tropospheric model parameters

date - current date

Returns:

the path delay due to the troposphere in m

pathDelay

public <T extends CalculusFieldElement<T>> T pathDelay(T elevation,
                                                       FieldGeodeticPoint<T> point,
                                                       T[] parameters,
                                                       FieldAbsoluteDate<T> date)

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

Specified by:

pathDelay in interface DiscreteTroposphericModel

Type Parameters:

T - type of the elements

Parameters:

elevation - the elevation of the satellite, in radians

point - station location

parameters - tropospheric model parameters

date - current date

Returns:

the path delay due to the troposphere in m