fr.cnes.sirius.patrius.signalpropagation.troposphere

Class SaastamoinenModel

java.lang.Object

fr.cnes.sirius.patrius.signalpropagation.troposphere.SaastamoinenModel

All Implemented Interfaces:

TroposphericCorrection, Serializable

public class SaastamoinenModel
extends Object
implements TroposphericCorrection

The modified Saastamoinen model. Estimates the path delay imposed to electro-magnetic signals by the troposphere according to the formula:

 δ = 2.277e-3 / cos z * (P + (1255 / T + 0.05) * e - B * tan2
 z) + δR
 

with the following input data provided to the model:

• z: zenith angle
• P: atmospheric pressure
• T: temperature
• e: partial pressure of water vapour
• B, δR: correction terms

The model supports custom δR correction terms to be read from a configuration file (saastamoinen-correction.txt) via the DataProvidersManager.

Constants used in model are defined as such in the Saastamoinen model article.

Author:

Thomas Neidhart

See Also:

"Guochang Xu, GPS - Theory, Algorithms and Applications, Springer, 2007", Serialized Form

Field Summary

Fields inherited from interface fr.cnes.sirius.patrius.signalpropagation.troposphere.TroposphericCorrection

ABSOLUTE_ZERO, H0, P0, RH0, T0

Constructor Summary

Constructors

Constructor and Description
SaastamoinenModel(double tStation, double pStation, double rHStation, double altitude) Create a new Saastamoinen model for the troposphere using the given environmental conditions [T, P, RH] and station altitude.

Method Summary

Modifier and Type	Method and Description
double	calculatePathDelay(double elevation) Calculates the tropospheric path delay for the signal path from a ground station to a satellite.
double	computeSignalDelay(double elevation) Calculates the tropospheric signal delay for the signal path from a ground station to a satellite.
static SaastamoinenModel	getStandardModel(double altitude) Create a new Saastamoinen model using a standard atmosphere model.

Methods inherited from class java.lang.Object

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

Methods inherited from interface fr.cnes.sirius.patrius.signalpropagation.troposphere.TroposphericCorrection

computeStandardValues, computeStandardValues

Constructor Detail

SaastamoinenModel

public SaastamoinenModel(double tStation,
                         double pStation,
                         double rHStation,
                         double altitude)

Create a new Saastamoinen model for the troposphere using the given environmental conditions [T, P, RH] and station altitude.

Parameters:

tStation - the temperature at the station [K]

pStation - the atmospheric pressure at the station [Pa]

rHStation - the relative humidity at the station [percent] (50% -> 0.5)

altitude - the altitude above sea level of the station [m]

Method Detail

getStandardModel

public static SaastamoinenModel getStandardModel(double altitude)

Create a new Saastamoinen model using a standard atmosphere model. The standard atmosphere model uses the following reference values at mean sea level:

• reference temperature: 18 degree Celsius
• reference pressure: 101325 Pa
• reference humidity: 50%

Parameters:

altitude - the altitude above the mean sea level of the station [m]

Returns:

a Saastamoinen model with standard environmental values

calculatePathDelay

public double calculatePathDelay(double elevation)

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

Parameters:

elevation - the elevation of the satellite in radians

Returns:

the path delay due to the troposphere in m

computeSignalDelay

public double computeSignalDelay(double elevation)

Calculates the tropospheric signal delay for the signal path from a ground station to a satellite. This method exists only for convenience reasons and returns the same as

   calculatePathDelay(double)/
   Constants.SPEED_OF_LIGHT
 

Specified by:

computeSignalDelay in interface TroposphericCorrection

Parameters:

elevation - the elevation of the satellite in radians

Returns:

the signal delay due to the troposphere in s