AGI.Foundation.Celestial Namespace 
Class  Description  

AtmosphericDragForce 
A simple model of atmospheric drag on a body according to its coefficient of drag and reference crosssectional area.
This model does not account for aerodynamic lift and is generally used for orbiting bodies which are perturbed by the atmosphere.
The details of the model are specified by choosing which density model
to use for the atmosphere.
 
AtmosphericRefractionModel 
Defines a refraction model.
 
CentralBodiesFacet 
A CalculationContextFacet that holds and provides information about
central bodies such as planets, moons, the sun, etc.
 
CentralBody 
A central body, such as a planet, star, asteroid, libration point, etc.
 
CentralBodyInertialAxes 
This class provides the Axes based on the STK definition of a CentralBody's Inertial Axes.
The Inertial Z axis aligns with the IauOrientationAxes Z axis of the CentralBody,
and the Inertial X axis aligns with the vector that is the cross product of the InternationalCelestialReferenceFrame
Z axis and the IAU Z axis, evaluated at the J2000 epoch.
 
ClassicalEquationOfEquinoxes  Represents the classical equation of the equinox as defined in the Explanatory Supplement to the Astronomical Almanac. This equation has been in use for many decades. For the updated equation of equinoxes defined by the IERS in 1996, see IersTechnicalNote21. To apply this equation of equinoxes, replace the existing EquationOfEquinoxes with an instance of this class. This class uses the existing NutationModel and PrecessionModel.  
ConstantForce 
Represents a constant force.
 
ConstantSolarGeophysicalData 
Represents the solar radiation and geomagnetic flux indices as constant values.
 
ConstantWindModel 
Represents a constant wind speed and direction.
 
ContinuousThrustForceModel 
Represents a force generated by continuous thrust.
 
CssiSolarGeophysicalData 
Represents the solar radiation and geomagnetic flux indices as they vary over time.
For more details, or to obtain updated data files, see:
CSSI Space Weather Data.
 
EarthCentralBody 
The planet Earth. You should generally obtain an instance of this class from the CentralBodiesFacet
instance in the calculation context instead of creating one directly.
 
EarthGravitationalModel1996 
Provides the semimajor axis, gravitational parameter, and 2nd, 3rd, 4th, and 5th zonal harmonic coefficients
for the Earth Gravitational Model of 1996 (EGM96) according to NASA Technical Publication 1998206861.
 
EarthGravitationalModel2008 
Provides the semimajor axis, gravitational parameter, and 2nd, 3rd, 4th, and 5th zonal harmonic coefficients
for the Earth Gravitational Model of 2008 (EGM2008) according to the Journal of Geophysical Research, Vol 117, Issue B4, April 2012.
 
EarthOrientationParameters 
Specifies Earth polar motion coordinates and the difference between UT1 and UTC.
 
EarthOrientationParametersData 
Specifies Earth Orientation Parameters at a specific instant.
 
EarthOrientationParametersFile 
Contains static methods to read EOP data in the Celestrak EOP data file format which is documented at
https://celestrak.com/SpaceData/EOPformat.asp.
 
EarthOrientationParametersReadOptions 
Specifies options for reading an EarthOrientationParametersFile.
 
EffectiveRadiusAtmosphericRefractionModel 
The effective radius model approximates the effects of refraction by assuming that the refractive index decreases linearly with altitude. This is only valid for objects at low altitude, typically less than 810 km.
This approximation leads to a very simple formula for the refracted elevation angle that is akin to computing the elevation angle relative to a scaled Earth surface. The Earth's radius is scaled by the effective radius factor,
typically a value between 0.3 and 2  the most common value is 4/3. Note that the model does not provide a manner for computing the effect of refraction on the signal path length.
 
EquationOfEquinoxes  Represents the equation of the equinox (also called the "nutation in right ascension" according to the Explanatory Supplement to the Astronomical Almanac) which defines the right ascension of the mean equinox with respect to the true equator and equinox. The two primary theories of the equation of the equinoxes are the ClassicalEquationOfEquinoxes and the UpdatedEquationOfEquinoxes. To apply a particular theory to calculations involving the Earth, obtain an instance of the EarthCentralBody from the CentralBodiesFacet and replace the existing EquationOfEquinoxes with a new instance.  
ForceEvaluator 
Base class for evaluators created by a ForceModel to compute the force.
 
ForceModel 
Represents a Newtonian force which can be used to specify the equations
of motion for a mass body located by an PropagationNewtonianPoint.
 
Iau1976Precession 
Provides Earth precession information according to the IAU 1976 model
 
Iau1980Nutation 
Provides Earth Nutation information according to the IAU 1980 model
 
Iau2000Orientation 
This is a collection of the orientation information available for central bodies.
The data comes from the Report of the IAU/IAG Working Group on Cartographic
Coordinates and Rotational Elements: 2000.
 
Iau2006Orientation 
This is a collection of the orientation information available for central bodies.
The data comes from the Report of the IAU/IAG Working Group on Cartographic
Coordinates and Rotational Elements: 2006.
 
Iau2006XysData 
A table of IAU2006 XYS data that is used to evaluate the transformation between the International Celestial
Reference Frame (ICRF) and the International Terrestrial Reference Frame (ITRF). It is usually preferable to use
the ReferenceFrame instances on EarthCentralBody rather than using this table directly.
 
Iau2009Orientation 
This is a collection of the orientation information available for central bodies.
The data comes from the Report of the IAU/IAG Working Group on Cartographic
Coordinates and Rotational Elements: 2009.
 
IauOrientationAxes 
The Axes representing the orientation of a CentralBody as represented by the data
from the IAU/IAG Working Group reports on rotational elements expressed in the
InertialAxes of the SolarSystemBarycenter.
See Iau2009Orientation for more details.
 
IauOrientationParameters 
A structure containing the orientation data computed at a particular time. The data
represent the direction of the pole of rotation and the rotation about that pole.
 
IersTechnicalNote21 
Provides Earth orientation parameters according to the IERS Technical Note 21.
 
IersTechnicalNote36RelativisticCorrectionForce 
A NewtonianSpecificForce that models the first order correction to the acceleration of a space object about a CentralBody.
The mathematical details for this model may be found in chapter 10 of "IERS Conventions (2010)".
The model was primarily designed for artificial satellites about Earth, but may be used with any space object and any CentralBody in the solar system.
The force always returns the primary contributor to the correction, the Schwarzchild field of the central body.
By default, corrections for framedragging and precession of the geodesic are also included, but may be turned off if so desired.
 
ItuRP834Version4AtmosphericRefractionModel 
ITUR P.8344 is the ITU recommendation concerning "Effects of tropospheric refraction on radio wave propagation."
The recommendation provides an analytical formula for the refracted elevation at the ground. The higher platform is assumed to be a satellite.
More information is available at ITU Radiocommunication Sector. Note that the model does not provide a manner for computing the effect of refraction on the signal path length.
 
JplDE 
The common base for classes for loading and accessing JPL DE files.
 
JplDE200 
Represents JPL DE200 ephemeris data.
 
JplDE403 
Represents JPL DE403 ephemeris data.
 
JplDE405 
Represents JPL DE405 ephemeris data.
 
JplDE421 
Represents JPL DE421 ephemeris data.
 
JplDE430 
Represents JPL DE430 ephemeris data.
 
JplDEFile 
Provides raw access to a JPL DE file.
 
JplDEFileEvaluator 
The class returned by GetEvaluator(JplDEDataIndex, EvaluatorGroup) to allow calculation of
timevarying information in the JPL DE file.
 
LibrationModel 
A model of the libration of a central body.
 
LinkRefracted 
A link between a Transmitter and Receiver that travels a refracted path. The refracted link relies on an underlying ExtensibleObject
link instance as well as a AtmosphericRefractionModel refraction model as the basis for computing the refracted link. In this way,
a refracted link which also accounts for light travel time can be achieved by configuring the refracted link with a LinkSpeedOfLight
instance as the underlying link. Or if light travel time is not important to the analysis, the LinkInstantaneous can be used as the basis for refraction.
 
MoonCentralBody 
The moon of the Earth. You should generally obtain an instance of this class from
the CentralBodiesFacet instance in the calculation context instead of creating one directly.
 
Nutation 
Holds nutation angles in longitude and in obliquity.
 
NutationModel 
A model of the nutation of a central body.
 
Precession 
Holds precession angles.
 
PrecessionModel 
A model of the precession of a central body.
 
ResultantForceBuilder 
A tool used by ForceModel objects to add their Principal and
Perturbation forces to a list of forces in a resultant force.
 
ScalarAtmosphericDensity 
Abstract base class for all atmospheric models used to calculate density.
 
ScalarDensityJacchia1970 
Calculates atmospheric density according to the Jacchia 1970 model.
The Jacchia models depend on the VectorToSun
to determine the shape of the atmosphere based on incident solar radiation.
 
ScalarDensityJacchiaRoberts 
Calculates atmospheric density according to the JacchiaRoberts model.
The Jacchia models depend on the VectorToSun
to determine the shape of the atmosphere based on incident solar radiation.
 
ScalarDensityMsis2000  Calculates atmospheric density according to the NRLMSISE 2000 model. MSIS 2000 is applicable from 0 km to 1000 km in altitude, and is meant for applications that reach across several atmospheric boundaries. It is not recommended for specialized tropospheric work, and if you are interested only in the thermosphere (120 km+) MSIS86 is recommended instead. MSIS 2000 was developed by the US Naval Research Laboratory. More information and documentation is available at http://modelweb.gsfc.nasa.gov/atmos/ Unlike other density models, this type does not make use of the VectorToSun and instead determines the shape of the atmosphere purely based on the time of day. If available, the MSIS models will make use of the time varying daily averages for the geomagnetic flux defined by the SolarGeophysicalData instance.  
ScalarDensityMsis86  Calculates atmospheric density according to the MSIS 1986 model. The MassSpectrometerIncoherentScatter1986 (MSIS86) neutral atmosphere model describes the neutral temperature and the densities of He, O, N2, O2, Ar, H, and N. The MSIS model is based on the extensive data compilation and analysis work of A. E. Hedin and his collaborators [A. E. Hedin et al., J. Geophys. Res. 82, 21392156, 1977; A. E. Hedin, J. Geophys. Res. 88, 10170 10188, 1983; A. E. Hedin, J. Geophys. Res. 92, 4649, 1987]. MSIS86 constitutes the upper part of the COSPAR International Reference Atmosphere (CIRA86). Unlike other density models, this type does not make use of the VectorToSun and instead determines the shape of the atmosphere purely based on the time of day. If available, the MSIS models will make use of the time varying daily averages for the geomagnetic flux defined by the SolarGeophysicalData instance.  
ScalarDensityMsis90  Calculates atmospheric density according to the MSIS 1990 model. This method is built off of the Fortran code written by Hedin et al. It is valid over the entire atmosphere. Above 72.5 km it is basically an updated MSIS 1986 density model, below 72.5 km it is based on the MAP Handbook (Labitzke et al., 1985), supplemented by other data. Unlike other density models, this type does not make use of the VectorToSun and instead determines the shape of the atmosphere purely based on the time of day. If available, the MSIS models will make use of the time varying daily averages for the geomagnetic flux defined by the SolarGeophysicalData instance.  
ScalarOccultation  A class that provides evaluators for percentage of occultation/eclipse at a position, as well as EclipseType. The percentage runs from 0.0 (completely lit) to 1.0 (total eclipse).  
ScalarOccultationCylindrical  Provides evaluators for percentage of occultation/eclipse at a position, as well as EclipseType using the cylindrical shadow model. The percentage runs from 0.0 (completely lit) to 1.0 (total eclipse). This occultation model is not nearly as accurate as ScalarOccultationDualCone, which should generally be used instead. However this cylindrical model was included for completeness.  
ScalarOccultationDualCone  Provides evaluators for percentage of occultation/eclipse at a position, as well as EclipseType using the dual cone shadow model. The percentage runs from 0.0 (completely lit) to 1.0 (total eclipse). This occultation model is much more accurate than ScalarOccultationCylindrical and is the one which should be used in most cases.  
ScalarOccultationNoShadow  This is a ScalarOccultation for use with SimpleSolarRadiationForce. This type models a lack of any shadow conditions, and is primarily intended for interplanetary missions. The same effect can be attained by using another ScalarOccultation without any bodies added to the OccludingBodies property, however this type has also been added for convenience.  
ScalarOccultationRegulatedDualCone  Provides evaluators for percentage of occultation/eclipse at a position, as well as EclipseType using the dual cone shadow model. The percentage runs from 0.0 (completely lit) to 1.0 (total eclipse). This shadow model should only be used in a SimpleSolarRadiationForce in conjunction with SolarRadiationBoundaryMitigation. It performs differently than the normal ScalarOccultationDualCone in that it treats the penumbra shadow condition as umbra, and does not allow the occultation factor to change during a propagation step. This functionality is required for correct results from the boundary mitigator, but in all other circumstances the normal dual cone occultation model should be used.  
Simon1994PlanetaryPositions 
Provides Point instances representing the positions of the planets computed using the
equations described in
Simon J.L., Bretagnon P., Chapront J., ChaprontTouze M., Francou G., Laskar J.,
1994, A&A 282, 663683.
 
SimpleSolarRadiationForce 
Represents the acceleration from pressure exerted on the given reflective area at the target position.
 
SolarGeophysicalData 
This class holds information on the F10.7 solar flux and the kp and ap geomagnetic flux.
 
SolarRadiationBoundaryMitigation 
Corrects for eclipse crossings during satellite propagation.
 
SolarSystemBarycenter 
The barycenter of a solar system.
 
SpaceControlFacilityAtmosphericRefractionModel 
The Satellite Control Facility (SCF) refraction model is based upon the paper "Refraction Correction, 'RC, Refraction Addition, 'RA, Milestone 4, Model 15.3A" by A. M. Smith, Aug 1978.
The 'RC model (pronounced tickRC) provides analytical formulas for computing the refraction angle and the refracted range (i.e., the effect of refraction on the signal path) of an observer
on the ground to a satellite target. The formulas depend on the surface refractivity at the ground site.
 
SphericalHarmonicGravity 
Represents the acceleration (force for a given unit mass) at a particular point
from the gravitational effects of the distribution of the Earth's mass.
 
SphericalHarmonicGravityField 
The immutable class that describes the chosen subset and configuration
of spherical harmonic gravitational model.
 
SphericalHarmonicGravityModel 
Contains the coefficient data for a gravity model, either specified upon construction or
read in from a file. This type is passed to a SphericalHarmonicGravityField
which down selects to the desired subset of this full model, and sets other configuration options.
The field is then used by SphericalHarmonicGravity in order to calculate the
gravitational force.
 
SunCentralBody 
The star at the center of our solar system. You should generally obtain an instance of this class from
the CentralBodiesFacet instance in the calculation context instead of creating one directly.
 
ThirdBodyGravity 
Represents the gravitational acceleration created by bodies other than the central body around
which a target object is orbiting.
 
ThirdBodyGravityThirdBodyInfo 
A combination of the position and gravitational parameter for a perturbing gravitational body.
 
TwoBodyGravity 
Represents the acceleration from a simple two body gravity model.
 
USStandardAtmosphere1976 
Provides scalars that calculate values using the U.S. Standard Atmosphere model, 1976 version.
This model is defined with respect to mean sea level, so you must configure the
MeanSeaLevel property on EarthCentralBody
before using this model.
 
USStandardAtmosphere1976Result 
The result of the calculation.
 
VectorRefractedDisplacement 
A vector representing the refracted displacement from an initial point to a final point as
both points move over time. The refracted displacement vector relies on an underlying VectorDisplacement
instance as well as an AtmosphericRefractionModel as the basis for computing the refracted displacement vector. In this way,
a refracted displacement vector which also accounts for light travel time can be achieved by configuring the refracted displacement vector with a VectorApparentDisplacement
instance as the underlying unrefracted displacement vector. If light travel time is not important to the analysis, the VectorTrueDisplacement can be used as the basis for refraction.
 
WindModel 
Defines a wind model for an atmosphere.
 
WorldGeodeticSystem1984 
Provides the set of four World Geodetic System of 1984, WGS84 (G873), defining constants according
to Table 3.1 on page 35 of the National Imagery and Mapping Agency Technical Report TR8350.2,
Third Edition, Amendment 1, 3 January 2000.

Interface  Description  

IJplDEWithMoonLibrationModel 
A JplDE which can return a libration model for the Moon.

Delegate  Description  

CentralBodyInertialAxesComputeOrientationParameters 
The definition of a function which computes a set of orientation parameters.
 
ComputeIauOrientationParameters 
The definition of a function which computes a set of orientation parameters.

Enumeration  Description  

CoefficientOfReflectivityType 
Defines the type of Reflectivity Coefficient used in initializing SimpleSolarRadiationForce.
 
EclipseType 
Enumerates the different types of shadowing that can occur during an eclipse.
 
JplDECentralBody 
The central bodies referenced in a JPL DE file.
 
JplDEDataIndex 
Indices of the data available in a JPL DE file.
 
KindOfForce 
Indicates the properties of a given force to be used when
distinguishing the behavior of forces when defining equations of motion.
 
RadiationVectorType 
Defines the type of vector to use between the target and the illuminating body in context of scalar occultation.
 
RoleOfForce 
An indication of how important a given force is in the overall composite force
acting on a given object. Certain integrators will use this information to
optimize the efficiency of evaluating the equations of motion during propagation of forces.
 
SphericalHarmonicsTideType 
This type defines types of tidal effects used to model SphericalHarmonicGravity.
