Package org.orekit.forces.drag.atmosphere

Class JB2008

java.lang.Object

org.orekit.forces.drag.atmosphere.JB2008

All Implemented Interfaces:

Serializable, Atmosphere

public class JB2008
extends Object
implements Atmosphere

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)

See Also:

Serialized Form

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
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.
double	getDensity(AbsoluteDate date, Vector3D position, Frame frame)	Get the local density.
<T extends RealFieldElement<T>> T	getDensity(FieldAbsoluteDate<T> date, FieldVector3D<T> position, Frame frame)	Get the local density.
<T extends RealFieldElement<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.
Frame	getFrame()	Get the frame of the central body.

Methods inherited from interface org.orekit.forces.drag.atmosphere.Atmosphere

getVelocity, getVelocity

Methods inherited from class java.lang.Object

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

Constructor Detail

JB2008

public JB2008(JB2008InputParameters parameters,
              PVCoordinatesProvider sun,
              BodyShape earth)

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

Method Detail

getFrame

public Frame getFrame()

Get the frame of the central body.

Specified by:

getFrame in interface Atmosphere

Returns:

frame of the central body.

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)
                  throws OrekitException

Get the local density with initial entries.

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)

Throws:

OrekitException - if altitude is below 90 km

getDensity

public <T extends RealFieldElement<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)
                                             throws OrekitException

Get the local density with initial entries.

Type Parameters:

T - type fo the field 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)

Throws:

OrekitException - if altitude is below 90 km

getDensity

public double getDensity(AbsoluteDate date,
                         Vector3D position,
                         Frame frame)
                  throws OrekitException

Get the local density.

Specified by:

getDensity in interface Atmosphere

Parameters:

date - current date

position - current position in frame

frame - the frame in which is defined the position

Returns:

local density (kg/m³)

Throws:

OrekitException - if date is out of range of solar activity

getDensity

public <T extends RealFieldElement<T>> T getDensity(FieldAbsoluteDate<T> date,
                                                    FieldVector3D<T> position,
                                                    Frame frame)
                                             throws OrekitException

Get the local density.

Specified by:

getDensity in interface Atmosphere

Type Parameters:

T - instance of RealFieldElement

Parameters:

date - current date

position - current position in frame

frame - the frame in which is defined the position

Returns:

local density (kg/m³)

Throws:

OrekitException - if date is out of range of solar activity model or if some frame conversion cannot be performed