org.orekit.models.earth

Class EarthStandardAtmosphereRefraction

java.lang.Object

org.orekit.models.earth.EarthStandardAtmosphereRefraction

All Implemented Interfaces:

Serializable, AtmosphericRefractionModel

public class EarthStandardAtmosphereRefraction
extends Object
implements AtmosphericRefractionModel

Implementation of refraction model for Earth standard atmosphere.

Refraction angle is 0 at zenith, about 1 arcminute at 45°, and 34 arcminutes at the horizon for optical wavelengths.

Refraction angle is computed according to Saemundssen formula quoted by Meeus. For reference, see Astronomical Algorithms (1998), 2nd ed, (ISBN 0-943396-61-1), chap. 15.

This formula is about 30 arcseconds of accuracy very close to the horizon, as variable atmospheric effects become very important.

Local pressure and temperature can be set to correct refraction at the viewpoint.

Since:

6.1

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static double	DEFAULT_CORRECTION_FACTOR Default correction factor value.
static double	DEFAULT_PRESSURE Default local pressure at viewpoint (Pa).
static double	DEFAULT_TEMPERATURE Default local temperature at viewpoint (K).
static double	STANDARD_ATM_PRESSURE NIST standard atmospheric pressure (Pa).
static double	STANDARD_ATM_TEMPERATURE NIST standard atmospheric temperature (K).

Constructor Summary

Constructors

Constructor and Description
EarthStandardAtmosphereRefraction() Creates a new default instance.
EarthStandardAtmosphereRefraction(double pressure, double temperature) Creates an instance given a specific pressure and temperature.

Method Summary

Methods

Modifier and Type	Method and Description
double	getPressure() Get the local pressure at the evaluation location.
double	getRefraction(double trueElevation) Compute the refraction angle from the true (geometrical) elevation.
double	getTemperature() Get the local temperature at the evaluation location.
void	setPressure(double pressure) Set the local pressure at the evaluation location
void	setTemperature(double temperature) Set the local temperature at the evaluation location

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_CORRECTION_FACTOR

public static final double DEFAULT_CORRECTION_FACTOR

Default correction factor value.

See Also:

Constant Field Values

DEFAULT_PRESSURE

public static final double DEFAULT_PRESSURE

Default local pressure at viewpoint (Pa).

See Also:

Constant Field Values

DEFAULT_TEMPERATURE

public static final double DEFAULT_TEMPERATURE

Default local temperature at viewpoint (K).

See Also:

Constant Field Values

STANDARD_ATM_PRESSURE

public static final double STANDARD_ATM_PRESSURE

NIST standard atmospheric pressure (Pa).

See Also:

Constant Field Values

STANDARD_ATM_TEMPERATURE

public static final double STANDARD_ATM_TEMPERATURE

NIST standard atmospheric temperature (K).

See Also:

Constant Field Values

Constructor Detail

EarthStandardAtmosphereRefraction

public EarthStandardAtmosphereRefraction()

Creates a new default instance.

EarthStandardAtmosphereRefraction

public EarthStandardAtmosphereRefraction(double pressure,
                                 double temperature)

Creates an instance given a specific pressure and temperature.

Parameters:

pressure - in Pascals (Pa)

temperature - in Kelvin (K)

Method Detail

getPressure

public double getPressure()

Get the local pressure at the evaluation location.

Returns:

the pressure (Pa)

setPressure

public void setPressure(double pressure)

Set the local pressure at the evaluation location

Otherwise the default value for the local pressure is set to DEFAULT_PRESSURE.

Parameters:

pressure - the pressure to set (Pa)

getTemperature

public double getTemperature()

Get the local temperature at the evaluation location.

Returns:

the temperature (K)

setTemperature

public void setTemperature(double temperature)

Set the local temperature at the evaluation location

Otherwise the default value for the local temperature is set to DEFAULT_TEMPERATURE.

Parameters:

temperature - the temperature to set (K)

getRefraction

public double getRefraction(double trueElevation)

Description copied from interface: AtmosphericRefractionModel

Compute the refraction angle from the true (geometrical) elevation.

Specified by:

getRefraction in interface AtmosphericRefractionModel

Parameters:

trueElevation - true elevation (rad)

Returns:

refraction angle (rad)