Package org.orekit.forces.drag.atmosphere

Class DTM2000

java.lang.Object

org.orekit.forces.drag.atmosphere.DTM2000

All Implemented Interfaces:

Serializable, Atmosphere

public class DTM2000
extends Object
implements Atmosphere

This atmosphere model is the realization of the DTM-2000 model.

It is described in the paper:
The DTM-2000 empirical thermosphere model with new data assimilation and constraints at lower boundary: accuracy and properties
S. Bruinsma, G. Thuillier and F. Barlier
Journal of Atmospheric and Solar-Terrestrial Physics 65 (2003) 1053–1070

This model provides dense output for altitudes beyond 120 km.

The model needs geographical and time information to compute general values, but also needs space weather data : mean and instantaneous solar flux and geomagnetic indices.

Mean solar flux is (for the moment) represented by the F10.7 indices. Instantaneous flux can be set to the mean value if the data is not available. Geomagnetic activity is represented by the Kp indice, which goes from 1 (very low activity) to 9 (high activity).

All these data can be found on the NOAA (National Oceanic and Atmospheric Administration) website.

Author:

R. Biancale, S. Bruinsma: original fortran routine, Fabien Maussion (java translation)

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static int	ATOMIC_NITROGEN	Identifier for atomic nitrogen.
static int	ATOMIC_OXYGEN	Identifier for atomic oxygen.
static int	HELIUM	Identifier for helium.
static int	HYDROGEN	Identifier for hydrogen.
static int	MOLECULAR_NITROGEN	Identifier for molecular nitrogen.
static int	MOLECULAR_OXYGEN	Identifier for molecular oxygen.

Constructor Summary

Constructors

Constructor	Description
DTM2000(DTM2000InputParameters parameters, PVCoordinatesProvider sun, BodyShape earth)	Simple constructor for independent computation.

Method Summary

Modifier and Type	Method	Description
double	getDensity(int day, double alti, double lon, double lat, double hl, double f, double fbar, double akp3, double akp24)	Get the local density with initial entries.
<T extends RealFieldElement<T>> T	getDensity(int day, T alti, T lon, T lat, T hl, double f, double fbar, double akp3, double akp24)	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.
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

Field Detail

HYDROGEN

public static final int HYDROGEN

Identifier for hydrogen.

See Also:

Constant Field Values

HELIUM

public static final int HELIUM

Identifier for helium.

See Also:

Constant Field Values

ATOMIC_OXYGEN

public static final int ATOMIC_OXYGEN

Identifier for atomic oxygen.

See Also:

Constant Field Values

MOLECULAR_NITROGEN

public static final int MOLECULAR_NITROGEN

Identifier for molecular nitrogen.

See Also:

Constant Field Values

MOLECULAR_OXYGEN

public static final int MOLECULAR_OXYGEN

Identifier for molecular oxygen.

See Also:

Constant Field Values

ATOMIC_NITROGEN

public static final int ATOMIC_NITROGEN

Identifier for atomic nitrogen.

See Also:

Constant Field Values

Constructor Detail

DTM2000

public DTM2000(DTM2000InputParameters parameters,
               PVCoordinatesProvider sun,
               BodyShape earth)
        throws OrekitException

Simple constructor for independent computation.

Parameters:

parameters - the solar and magnetic activity data

sun - the sun position

earth - the earth body shape

Throws:

OrekitException - if some resource file reading error occurs

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(int day,
                         double alti,
                         double lon,
                         double lat,
                         double hl,
                         double f,
                         double fbar,
                         double akp3,
                         double akp24)
                  throws OrekitException

Get the local density with initial entries.

Parameters:

day - day of year

alti - altitude in meters

lon - local longitude (rad)

lat - local latitude (rad)

hl - local solar time in rad (O hr = 0 rad)

f - instantaneous solar flux (F10.7)

fbar - mean solar flux (F10.7)

akp3 - 3 hrs geomagnetic activity index (1-9)

akp24 - Mean of last 24 hrs geomagnetic activity index (1-9)

Returns:

the local density (kg/m³)

Throws:

OrekitException - if altitude is outside of supported range

getDensity

public <T extends RealFieldElement<T>> T getDensity(int day,
                                                    T alti,
                                                    T lon,
                                                    T lat,
                                                    T hl,
                                                    double f,
                                                    double fbar,
                                                    double akp3,
                                                    double akp24)
                                             throws OrekitException

Get the local density with initial entries.

Type Parameters:

T - type of the field elements

Parameters:

day - day of year

alti - altitude in meters

lon - local longitude (rad)

lat - local latitude (rad)

hl - local solar time in rad (O hr = 0 rad)

f - instantaneous solar flux (F10.7)

fbar - mean solar flux (F10.7)

akp3 - 3 hrs geomagnetic activity index (1-9)

akp24 - Mean of last 24 hrs geomagnetic activity index (1-9)

Returns:

the local density (kg/m³)

Throws:

OrekitException - if altitude is outside of supported range

Since:

9.0

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 model or if some frame conversion cannot be performed

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