Package org.orekit.models.earth.atmosphere

Class JB2008

java.lang.Object

org.orekit.models.earth.atmosphere.AbstractSunInfluencedAtmosphere

org.orekit.models.earth.atmosphere.AbstractJacchiaBowmanModel

org.orekit.models.earth.atmosphere.JB2008

All Implemented Interfaces:

Atmosphere

public class JB2008
extends AbstractJacchiaBowmanModel

This is the realization of the Jacchia-Bowman 2008 atmospheric model.

It is described in the paper:
A New Empirical Thermospheric Density Model JB2008 Using New Solar Indices
Bruce R. Bowman & al.
AIAA 2008-6438

Two computation methods are proposed to the user:

• one OREKIT independent and compliant with initial FORTRAN routine entry values: getDensity(double, double, double, double, double, double, double, double, double, double, double, double, double, double, double).
• one compliant with OREKIT Atmosphere interface, necessary to the drag force model computation.

This model provides dense output for all altitudes and positions. Output data are :

• Exospheric Temperature above Input Position (deg K)
• Temperature at Input Position (deg K)
• Total Mass-Density at Input Position (kg/m³)

The model needs geographical and time information to compute general values, but also needs space weather data : mean and daily solar flux, retrieved through different indices, and planetary geomagnetic indices.
More information on these indices can be found on the official JB2008 website.

Author:

Bruce R Bowman (HQ AFSPC, Space Analysis Division), 2008: FORTRAN routine, Pascal Parraud (java translation)

Constructor Summary

Constructors

Constructor	Description
JB2008(JB2008InputParameters parameters, ExtendedPositionProvider sun, BodyShape earth)	Constructor with space environment information for internal computation.
JB2008(JB2008InputParameters parameters, ExtendedPositionProvider sun, BodyShape earth, TimeScale utc)	Constructor with space environment information for internal computation.

Method Summary

Modifier and Type	Method	Description
protected double	computeTc(AbsoluteDate date)	Computes the temperature equation.
protected double	computeTInf(AbsoluteDate date, double tsubl, double dtclst)	Computes the local exospheric temperature.
protected <T extends CalculusFieldElement<T>> T	computeTInf(AbsoluteDate date, T tsubl, T dtclst)	Computes the local exospheric temperature.
double	getDensity(double dateMJD, double sunRA, double sunDecli, double satLon, double satLat, double satAlt, double f10, double f10B, double s10, double s10B, double xm10, double xm10B, double y10, double y10B, double dstdtc)	Get the local density with initial entries.
<T extends CalculusFieldElement<T>> T	getDensity(T dateMJD, T sunRA, T sunDecli, T satLon, T satLat, T satAlt, double f10, double f10B, double s10, double s10B, double xm10, double xm10B, double y10, double y10B, double dstdtc)	Get the local density with initial entries.
protected double	getF10(AbsoluteDate date)	Get the 10.7-cm Solar flux (1e-22*Watt/(m²*Hertz)) (Tabular time 1.0 day earlier).
protected double	getF10B(AbsoluteDate date)	Get the 10.7-cm Solar Flux, averaged 81-day centered on the input time (Tabular time 1.0 day earlier).
protected double	semian(AbsoluteDate date, double day, double altKm)	Computes the semi-annual variation (delta log(rho)).
protected <T extends CalculusFieldElement<T>> T	semian(AbsoluteDate date, T day, T altKm)	Computes the semi-annual variation (delta log(rho)).

Methods inherited from class org.orekit.models.earth.atmosphere.AbstractJacchiaBowmanModel

computeDensity, computeDensity, getDensity, getDensity, getEarth, getFrame, getUtc

Methods inherited from class org.orekit.models.earth.atmosphere.AbstractSunInfluencedAtmosphere

getSun, getSunPosition, getSunPosition

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.atmosphere.Atmosphere

getVelocity, getVelocity

Constructor Detail

JB2008

@DefaultDataContext
public JB2008(JB2008InputParameters parameters,
              ExtendedPositionProvider sun,
              BodyShape earth)

Constructor with space environment information for internal computation.

This method uses the default data context.

Parameters:

parameters - the solar and magnetic activity data

sun - the sun position

earth - the earth body shape

See Also:

JB2008(JB2008InputParameters, ExtendedPositionProvider, BodyShape, TimeScale)

JB2008

public JB2008(JB2008InputParameters parameters,
              ExtendedPositionProvider sun,
              BodyShape earth,
              TimeScale utc)

Constructor with space environment information for internal computation.

Parameters:

parameters - the solar and magnetic activity data

sun - the sun position

earth - the earth body shape

utc - UTC time scale. Used to computed the day fraction.

Since:

10.1

Method Detail

getDensity

public double getDensity(double dateMJD,
                         double sunRA,
                         double sunDecli,
                         double satLon,
                         double satLat,
                         double satAlt,
                         double f10,
                         double f10B,
                         double s10,
                         double s10B,
                         double xm10,
                         double xm10B,
                         double y10,
                         double y10B,
                         double dstdtc)

Get the local density with initial entries.

The method creates a new instance of JB2008 model and set the input solar activity data equal to the provided one. These data are then available form AbsoluteDate.PAST_INFINITY to AbsoluteDate.FUTURE_INFINITY.

Parameters:

dateMJD - date and time, in modified julian days and fraction

sunRA - Right Ascension of Sun (radians).

sunDecli - Declination of Sun (radians).

satLon - Right Ascension of position (radians)

satLat - Geocentric latitude of position (radians)

satAlt - Height of position (m)

f10 - 10.7-cm Solar flux (1e^-22*Watt/(m²*Hertz))
(Tabular time 1.0 day earlier)

f10B - 10.7-cm Solar Flux, averaged 81-day centered on the input time
(Tabular time 1.0 day earlier)

s10 - EUV index (26-34 nm) scaled to F10
(Tabular time 1 day earlier)

s10B - UV 81-day averaged centered index (Tabular time 1 day earlier)

xm10 - MG2 index scaled to F10
(Tabular time 2.0 days earlier)

xm10B - MG2 81-day ave. centered index
(Tabular time 2.0 days earlier)

y10 - Solar X-Ray & Lya index scaled to F10
(Tabular time 5.0 days earlier)

y10B - Solar X-Ray & Lya 81-day ave. centered index
(Tabular time 5.0 days earlier)

dstdtc - Temperature change computed from Dst index

Returns:

total mass-Density at input position (kg/m³)

getDensity

public <T extends CalculusFieldElement<T>> T getDensity(T dateMJD,
                                                        T sunRA,
                                                        T sunDecli,
                                                        T satLon,
                                                        T satLat,
                                                        T satAlt,
                                                        double f10,
                                                        double f10B,
                                                        double s10,
                                                        double s10B,
                                                        double xm10,
                                                        double xm10B,
                                                        double y10,
                                                        double y10B,
                                                        double dstdtc)

Get the local density with initial entries.

The method creates a new instance of JB2008 model and set the input solar activity data equal to the provided one. These data are then available form AbsoluteDate.PAST_INFINITY to AbsoluteDate.FUTURE_INFINITY.

Type Parameters:

T - type of the elements

Parameters:

dateMJD - date and time, in modified julian days and fraction

sunRA - Right Ascension of Sun (radians).

sunDecli - Declination of Sun (radians).

satLon - Right Ascension of position (radians)

satLat - Geocentric latitude of position (radians)

satAlt - Height of position (m)

f10 - 10.7-cm Solar flux (1e^-22*Watt/(m²*Hertz))
(Tabular time 1.0 day earlier)

f10B - 10.7-cm Solar Flux, averaged 81-day centered on the input time
(Tabular time 1.0 day earlier)

s10 - EUV index (26-34 nm) scaled to F10
(Tabular time 1 day earlier)

s10B - UV 81-day averaged centered index (Tabular time 1 day earlier)

xm10 - MG2 index scaled to F10
(Tabular time 2.0 days earlier)

xm10B - MG2 81-day ave. centered index
(Tabular time 2.0 days earlier)

y10 - Solar X-Ray & Lya index scaled to F10
(Tabular time 5.0 days earlier)

y10B - Solar X-Ray & Lya 81-day ave. centered index
(Tabular time 5.0 days earlier)

dstdtc - Temperature change computed from Dst index

Returns:

total mass-Density at input position (kg/m³)

computeTInf

protected double computeTInf(AbsoluteDate date,
                             double tsubl,
                             double dtclst)

Computes the local exospheric temperature.

Specified by:

computeTInf in class AbstractJacchiaBowmanModel

Parameters:

date - computation epoch

tsubl - exospheric temperature ("tsubl" term), given by Equation (17)

dtclst - correction to dTc for local solar time and lat correction

Returns:

the local exospheric temperature

computeTc

protected double computeTc(AbsoluteDate date)

Computes the temperature equation.

Specified by:

computeTc in class AbstractJacchiaBowmanModel

Parameters:

date - computation epoch

Returns:

the temperature equation

getF10

protected double getF10(AbsoluteDate date)

Get the 10.7-cm Solar flux (1e^-22*Watt/(m²*Hertz))
(Tabular time 1.0 day earlier).

Specified by:

getF10 in class AbstractJacchiaBowmanModel

Parameters:

date - computation epoch

Returns:

the 10.7-cm Solar flux from model input parameters

getF10B

protected double getF10B(AbsoluteDate date)

Get the 10.7-cm Solar Flux, averaged 81-day centered on the input time
(Tabular time 1.0 day earlier).

Specified by:

getF10B in class AbstractJacchiaBowmanModel

Parameters:

date - computation epoch

Returns:

the 10.7-cm Solar Flux, averaged 81-day centered on the input time

computeTInf

protected <T extends CalculusFieldElement<T>> T computeTInf(AbsoluteDate date,
                                                            T tsubl,
                                                            T dtclst)

Computes the local exospheric temperature.

Specified by:

computeTInf in class AbstractJacchiaBowmanModel

Type Parameters:

T - type of the elements

Parameters:

date - computation epoch

tsubl - exospheric temperature ("tsubl" term), given by Equation (17)

dtclst - correction to dTc for local solar time and lat correction

Returns:

the local exospheric temperature

semian

protected double semian(AbsoluteDate date,
                        double day,
                        double altKm)

Computes the semi-annual variation (delta log(rho)).

Specified by:

semian in class AbstractJacchiaBowmanModel

Parameters:

date - computation epoch

day - day of year

altKm - height (km)

Returns:

semi-annual variation

semian

protected <T extends CalculusFieldElement<T>> T semian(AbsoluteDate date,
                                                       T day,
                                                       T altKm)

Computes the semi-annual variation (delta log(rho)).

Specified by:

semian in class AbstractJacchiaBowmanModel

Type Parameters:

T - type of the elements

Parameters:

date - computation epoch

day - day of year

altKm - height (km)

Returns:

semi-annual variation