User Manual 4.0 Semi-analytical propagation - Historique des versions

Admin : /* Third Body */

2020-09-22T08:31:06Z

Third Body

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	=== Third Body ===		=== Third Body ===

	Third body perturbation can be computed using <code>StelaThirdBodyAttraction</code>. It includes Sun and Moon perturbation (although any celestial body perturbation can be taken into account since java interfaces are used). The theory is developped in Legendre polynomials hence the model can be customised through the degree of the polynomial used. Any Third body ephemerids can be used (implementing <code>CelestialBody</code> interface). Original STELA model is Meeus model. Short periodic terms and partial derivatives are available.		Third body perturbation can be computed using <code>StelaThirdBodyAttraction</code>. It includes Sun and Moon perturbation (although any celestial body perturbation can be taken into account since java interfaces are used). The theory is developped in Legendre polynomials hence the model can be customised through the degree of the polynomial used (up to order 8). Any Third body ephemerids can be used (implementing <code>CelestialBody</code> interface). Original STELA model is Meeus model. Short periodic terms (up to order 2) and partial derivatives (up to order 4) are available.

	=== Solar radiation pressure (SRP) ===		=== Solar radiation pressure (SRP) ===

Admin le 21 février 2018 à 14:25

2018-02-21T14:25:04Z

← Version précédente		Version du 21 février 2018 à 14:25
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	== Introduction ==		== Introduction ==
	=== Scope ===		=== Scope ===
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	===Propagator===		===Propagator===

	The propagator is defined using a numerical integrator. Any fixed-stepsize integrator can be used. Adaptative stepsize integrator should not be used. The two last parameters in StelaGTOPropagator constructor define the behaviour of the propagator in case of re-entry problems (see [{{~~PathCurrentJavaDoc~~}}/fr/cnes/sirius/patrius/stela/propagation/StelaGTOPropagator.html StelaGTOPropagator Javadoc] for more information). To sum-up, re-entry fails because of integration step which is too large (usually a day). As a result the reentry strategy is to reduce the integration step (division by 2) until some physical result is obtained. The first parameter "maxShiftIn" indicates the maximum number of integration steps STELA will try to correct (default is 5). The second parameter "minStepSizeIn" indicates the smallest step size allowed by the user (default is 1 second). If STELA could not find a suitable solution using the smallest allowed stepsize and in number of corrected integration step, an exception will be thrown. In the example bellow, the maximum number of integration step is 5 and the smallest allowed stepsize is 1s.		The propagator is defined using a numerical integrator. Any fixed-stepsize integrator can be used. Adaptative stepsize integrator should not be used. The two last parameters in StelaGTOPropagator constructor define the behaviour of the propagator in case of re-entry problems (see [{{JavaDoc4.0}}/fr/cnes/sirius/patrius/stela/propagation/StelaGTOPropagator.html StelaGTOPropagator Javadoc] for more information). To sum-up, re-entry fails because of integration step which is too large (usually a day). As a result the reentry strategy is to reduce the integration step (division by 2) until some physical result is obtained. The first parameter "maxShiftIn" indicates the maximum number of integration steps STELA will try to correct (default is 5). The second parameter "minStepSizeIn" indicates the smallest step size allowed by the user (default is 1 second). If STELA could not find a suitable solution using the smallest allowed stepsize and in number of corrected integration step, an exception will be thrown. In the example bellow, the maximum number of integration step is 5 and the smallest allowed stepsize is 1s.

	<syntaxhighlight lang="java">		<syntaxhighlight lang="java">

Admin : /* Contents */

2018-02-21T12:56:34Z

Contents

Voir les modifications

Admin : /* Javadoc */

2018-02-21T10:53:21Z

Javadoc

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	The packages associated to Stela propagator are :		The packages associated to Stela propagator are :

	\|=~~(% colspan~~="3" %)Library~~\|=(% colspan~~="6" %)Javadoc		{\| class="wikitable"
	\|~~(% colspan="3" %)~~Patrius\|~~(% colspan="6" %)~~[{{~~PathCurrentJavaDoc~~}}/fr/cnes/sirius/patrius/stela/package-summary.html Package fr.cnes.sirius.patrius.stela]		\|-
	\|~~(% colspan="3" %)~~Patrius\|~~(% colspan="6" %)~~[{{~~PathCurrentJavaDoc~~}}/fr/cnes/sirius/patrius/stela/bodies/package-summary.html Package fr.cnes.sirius.patrius.stela.bodies]		! scope="col"\| Library
	\|~~(% colspan="3" %)~~Patrius\|~~(% colspan="6" %)~~[{{~~PathCurrentJavaDoc~~}}/fr/cnes/sirius/patrius/stela/forces/package-summary.html Package fr.cnes.sirius.patrius.stela.forces]		! scope="col"\| Javadoc
	\|~~(% colspan="3" %)~~Patrius\|~~(% colspan="6" %)~~[{{~~PathCurrentJavaDoc~~}}/fr/cnes/sirius/patrius/stela/forces/atmospheres/package-summary.html Package fr.cnes.sirius.patrius.stela.forces.atmospheres]		\|-
	\|~~(% colspan="3" %)~~Patrius\|~~(% colspan="6" %)~~[{{~~PathCurrentJavaDoc~~}}/fr/cnes/sirius/patrius/stela/forces/drag/package-summary.html Package fr.cnes.sirius.patrius.stela.forces.drag]		\|Patrius
	\|~~(% colspan="3" %)~~Patrius\|~~(% colspan="6" %)~~[{{~~PathCurrentJavaDoc~~}}/fr/cnes/sirius/patrius/stela/forces/gravity/package-summary.html Package fr.cnes.sirius.patrius.stela.forces.gravity]		\|[{{JavaDoc4.0}}/fr/cnes/sirius/patrius/stela/package-summary.html Package fr.cnes.sirius.patrius.stela]
	\|~~(% colspan="3" %)~~Patrius\|~~(% colspan="6" %)~~[{{~~PathCurrentJavaDoc~~}}/fr/cnes/sirius/patrius/stela/forces/radiation/package-summary.html Package fr.cnes.sirius.patrius.stela.forces.radiation]		\|-
	\|~~(% colspan="3" %)~~Patrius\|~~(% colspan="6" %)~~[{{~~PathCurrentJavaDoc~~}}/fr/cnes/sirius/patrius/stela/forces/noninertial/package-summary.html Package fr.cnes.sirius.patrius.stela.forces.noninertial]		\|Patrius
	\|~~(% colspan="3" %)~~Patrius\|~~(% colspan="6" %)~~[{{~~PathCurrentJavaDoc~~}}/fr/cnes/sirius/patrius/stela/orbits/package-summary.html Package fr.cnes.sirius.patrius.stela.orbits]		\|[{{JavaDoc4.0}}/fr/cnes/sirius/patrius/stela/bodies/package-summary.html Package fr.cnes.sirius.patrius.stela.bodies]
	\|~~(% colspan="3" %)~~Patrius\|~~(% colspan="6" %)~~[{{~~PathCurrentJavaDoc~~}}/fr/cnes/sirius/patrius/stela/propagation/package-summary.html Package fr.cnes.sirius.patrius.stela.propagation]		\|-
			\|Patrius
			\|[{{JavaDoc4.0}}/fr/cnes/sirius/patrius/stela/forces/package-summary.html Package fr.cnes.sirius.patrius.stela.forces]
			\|-
			\|Patrius
			\|[{{JavaDoc4.0}}/fr/cnes/sirius/patrius/stela/forces/atmospheres/package-summary.html Package fr.cnes.sirius.patrius.stela.forces.atmospheres]
			\|-
			\|Patrius
			\|[{{JavaDoc4.0}}/fr/cnes/sirius/patrius/stela/forces/drag/package-summary.html Package fr.cnes.sirius.patrius.stela.forces.drag]
			\|-
			\|Patrius
			\|[{{JavaDoc4.0}}/fr/cnes/sirius/patrius/stela/forces/gravity/package-summary.html Package fr.cnes.sirius.patrius.stela.forces.gravity]
			\|-
			\|Patrius
			\|[{{JavaDoc4.0}}/fr/cnes/sirius/patrius/stela/forces/radiation/package-summary.html Package fr.cnes.sirius.patrius.stela.forces.radiation]
			\|-
			\|Patrius
			\|[{{JavaDoc4.0}}/fr/cnes/sirius/patrius/stela/forces/noninertial/package-summary.html Package fr.cnes.sirius.patrius.stela.forces.noninertial]
			\|-
			\|Patrius
			\|[{{JavaDoc4.0}}/fr/cnes/sirius/patrius/stela/orbits/package-summary.html Package fr.cnes.sirius.patrius.stela.orbits]
			\|-
			\|Patrius
			\|[{{JavaDoc4.0}}/fr/cnes/sirius/patrius/stela/propagation/package-summary.html Package fr.cnes.sirius.patrius.stela.propagation]
			\|}

	=== Links ===		=== Links ===

Admin le 19 février 2018 à 16:21

2018-02-19T16:21:49Z

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	=== Tutorial 1: Building a Keplerian Simulation ===		=== Tutorial 1: Building a Keplerian Simulation ===
	{{specialInclusion prefix=$theme_sub section="Tuto1"/}}		{{specialInclusion prefix=$theme_sub section="Tuto1"/}}

			[[Category:User_Manual_4.0_Orbit_Propagation]]

Admin : /* Configuration: Frames and Time scales */

2018-02-19T16:18:41Z

Configuration: Frames and Time scales

← Version précédente		Version du 19 février 2018 à 16:18
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	===Configuration: Frames and Time scales===		===Configuration: Frames and Time scales===

	Frames configuration		'''Frames configuration'''

	A specific frames configuration is provided to match STELA frames configuration. This configuration is used calling: <code>FramesFactory.setConfiguration(FramesConfigurationFactory.getStelaConfiguration());</code>		A specific frames configuration is provided to match STELA frames configuration. This configuration is used calling: <code>FramesFactory.setConfiguration(FramesConfigurationFactory.getStelaConfiguration());</code>

	Time scales		'''Time scales'''

	STELA uses a constant UTC-TAI shift. This can be set using the following code:		STELA uses a constant UTC-TAI shift. This can be set using the following code:

Admin : /* Orbits */

2018-02-19T16:17:53Z

Orbits

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	=== Orbits===		=== Orbits===
	Conversions Mean <-> Osculating		'''Conversions Mean <-> Osculating'''

	Conversion is performed by taking into account provided forces short periodic terms. Integration of the équations of motion is performed in mean elements. Osculating elements are only used for user input/output and for computing atmospheric drag.		Conversion is performed by taking into account provided forces short periodic terms. Integration of the équations of motion is performed in mean elements. Osculating elements are only used for user input/output and for computing atmospheric drag.

	Stela Equinoctial Elements		'''Stela Equinoctial Elements'''

	Stela equinoctial elements slightly differ from Patrius equinoctial elements. They are defined as follow:		Stela equinoctial elements slightly differ from Patrius equinoctial elements. They are defined as follow:

			{\| class="wikitable"
	\|~~=(% colspan~~="3" %)Parameter~~\|=(% colspan~~="6" %)Definition		\|-
	\|~~(% colspan="3" %)~~'''a'''\|~~(% colspan="6" %)~~Semi-major axis		! scope="col"\| Parameter
	\|~~(% colspan="3" %)~~'''<math>\xi</math>'''\|~~(% colspan="6" %)~~<math>\xi =\omega +\Omega+M</math>		! scope="col"\| Definition
	\|~~(% colspan="3" %)~~'''ex'''\|~~(% colspan="6" %)~~<math>e_x = e \cos( \Omega + \omega )</math>		\|-
	\|~~(% colspan="3" %)~~'''ey'''\|~~(% colspan="6" %)~~<math>e_y = e \sin( \Omega + \omega )</math>		\| '''a'''
	\|~~(% colspan="3" %)~~'''ix'''\|~~(% colspan="6" %)~~<math>i_x = \sin(i / 2) \cos( \Omega )</math>		\| Semi-major axis
	\|~~(% colspan="3" %)~~'''iy'''\|~~(% colspan="6" %)~~<math>i_y = \sin(i / 2) \sin( \Omega )</math>		\|-
			\| '''<math>\xi</math>'''
			\| <math>\xi =\omega +\Omega+M</math>
			\|-
			\| '''ex'''
			\| <math>e_x = e \cos( \Omega + \omega )</math>
			\|-
			\| '''ey'''
			\| <math>e_y = e \sin( \Omega + \omega )</math>
			\|-
			\| '''ix'''
			\| <math>i_x = \sin(i / 2) \cos( \Omega )</math>
			\|-
			\| '''iy'''
			\| <math>i_y = \sin(i / 2) \sin( \Omega )</math>
			\|}

	== Getting Started ==		== Getting Started ==

Admin : /* Solar radiation pressure (SRP) */

2018-02-19T16:12:22Z

Solar radiation pressure (SRP)

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	'''SRPPotential'''		'''SRPPotential'''

	This class compute the SRP force without eclipses. This can be used for a faster computation. Short periods are not implemented for this class.		This class compute the SRP force without eclipses. This can be used for a faster computation. Short periods are not implemented for this class.

	'''SRPSquaring'''		'''SRPSquaring'''

	The SRP is computed using Simpson Squaring (see [ORB_GTO_Home#HUsefulDocuments useful documents] for detailed algorithm). Sun eclipses are taken into account. Partial derivatives and short periods are not implemented for this class.		The SRP is computed using Simpson Squaring (see [ORB_GTO_Home#HUsefulDocuments useful documents] for detailed algorithm). Sun eclipses are taken into account. Partial derivatives and short periods are not implemented for this class.

	'''StelaSRPSquaring'''		'''StelaSRPSquaring'''

	This class implements the original Stela SRP force model: perturbation is computed using SRPSquaring class whereas partial derivatives are computed using SRPPotential class.		This class implements the original Stela SRP force model: perturbation is computed using SRPSquaring class whereas partial derivatives are computed using SRPPotential class.

	==== Atmospheric Drag ====		=== Atmospheric Drag ===

	Atmospheric Drag is computed using a Simpson squaring method using <code>StelaAtmosphericDrag</code> class. Any atmospheric model can be used (implementing <code>Atmosphere</code> interface). Original STELA model is MSIS-00. For partial derivatives computation, two mecanisms are available (computation of variation of atmospheric density with respect either to altitude or to x, y, z position).		Atmospheric Drag is computed using a Simpson squaring method using <code>StelaAtmosphericDrag</code> class. Any atmospheric model can be used (implementing <code>Atmosphere</code> interface). Original STELA model is MSIS-00. For partial derivatives computation, two mecanisms are available (computation of variation of atmospheric density with respect either to altitude or to x, y, z position).
	The drag coefficient used to compute the atmospheric drag can be constant or a function of spacecraft altitude.		The drag coefficient used to compute the atmospheric drag can be constant or a function of spacecraft altitude.

	==== Non-inertial contribution ====		=== Non-inertial contribution ===

	Stela equations of motion are integrated in CIRF frame. The integration frame being non-inertial, acceleration accounting for non-inertial contribution can be added to the equations of motion. This is simply done by adding a <code>NonInertialContribution</code> instance to Stela force models. The user can choose the reference frame considered as inertial (between CIRF, GCRF and MOD). This contribution is computed thanks to Simpson squaring method. Partial derivatives are not computed.		Stela equations of motion are integrated in CIRF frame. The integration frame being non-inertial, acceleration accounting for non-inertial contribution can be added to the equations of motion. This is simply done by adding a <code>NonInertialContribution</code> instance to Stela force models. The user can choose the reference frame considered as inertial (between CIRF, GCRF and MOD). This contribution is computed thanks to Simpson squaring method. Partial derivatives are not computed.

Admin : /* Solar radiation pressure (SRP) */

2018-02-19T16:11:44Z

Solar radiation pressure (SRP)

← Version précédente		Version du 19 février 2018 à 16:11
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	Third body perturbation can be computed using <code>StelaThirdBodyAttraction</code>. It includes Sun and Moon perturbation (although any celestial body perturbation can be taken into account since java interfaces are used). The theory is developped in Legendre polynomials hence the model can be customised through the degree of the polynomial used. Any Third body ephemerids can be used (implementing <code>CelestialBody</code> interface). Original STELA model is Meeus model. Short periodic terms and partial derivatives are available.		Third body perturbation can be computed using <code>StelaThirdBodyAttraction</code>. It includes Sun and Moon perturbation (although any celestial body perturbation can be taken into account since java interfaces are used). The theory is developped in Legendre polynomials hence the model can be customised through the degree of the polynomial used. Any Third body ephemerids can be used (implementing <code>CelestialBody</code> interface). Original STELA model is Meeus model. Short periodic terms and partial derivatives are available.

	==== Solar radiation pressure (SRP) ====		=== Solar radiation pressure (SRP) ===

	Sun position is computed using provided Sun ephemerids model. Original STELA model is Meeus model.		Sun position is computed using provided Sun ephemerids model. Original STELA model is Meeus model.<br>
	Two different SRP models are available. A third one has been added to gather STELA features in one single model (perturbation taking into account eclipse, partial dérivatives not taking eclipses into account).		Two different SRP models are available. A third one has been added to gather STELA features in one single model (perturbation taking into account eclipse, partial dérivatives not taking eclipses into account).

	SRPPotential		'''SRPPotential'''
	This class compute the SRP force without eclipses. This can be used for a faster computation. Short periods are not implemented for this class.		This class compute the SRP force without eclipses. This can be used for a faster computation. Short periods are not implemented for this class.

	SRPSquaring		'''SRPSquaring'''
	The SRP is computed using Simpson Squaring (see [ORB_GTO_Home#HUsefulDocuments useful documents] for detailed algorithm). Sun eclipses are taken into account. Partial derivatives and short periods are not implemented for this class.		The SRP is computed using Simpson Squaring (see [ORB_GTO_Home#HUsefulDocuments useful documents] for detailed algorithm). Sun eclipses are taken into account. Partial derivatives and short periods are not implemented for this class.

	StelaSRPSquaring		'''StelaSRPSquaring'''
	This class implements the original Stela SRP force model: perturbation is computed using SRPSquaring class whereas partial derivatives are computed using SRPPotential class.		This class implements the original Stela SRP force model: perturbation is computed using SRPSquaring class whereas partial derivatives are computed using SRPPotential class.

Admin : /* Third Body */

2018-02-19T16:11:03Z

Third Body

← Version précédente		Version du 19 février 2018 à 16:11
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	Solid tides from both Sun and Moon can be computed using <code>SolidTidesAcc</code>. Any Third body ephemerids can be used (implementing <code>CelestialBody</code> interface). Original STELA model is Meeus model. Short Periodic terms and Partial derivatives are not available.		Solid tides from both Sun and Moon can be computed using <code>SolidTidesAcc</code>. Any Third body ephemerids can be used (implementing <code>CelestialBody</code> interface). Original STELA model is Meeus model. Short Periodic terms and Partial derivatives are not available.

	==== Third Body ====		=== Third Body ===

	Third body perturbation can be computed using <code>StelaThirdBodyAttraction</code>. It includes Sun and Moon perturbation (although any celestial body perturbation can be taken into account since java interfaces are used). The theory is developped in Legendre polynomials hence the model can be customised through the degree of the polynomial used. Any Third body ephemerids can be used (implementing <code>CelestialBody</code> interface). Original STELA model is Meeus model. Short periodic terms and partial derivatives are available.		Third body perturbation can be computed using <code>StelaThirdBodyAttraction</code>. It includes Sun and Moon perturbation (although any celestial body perturbation can be taken into account since java interfaces are used). The theory is developped in Legendre polynomials hence the model can be customised through the degree of the polynomial used. Any Third body ephemerids can be used (implementing <code>CelestialBody</code> interface). Original STELA model is Meeus model. Short periodic terms and partial derivatives are available.

User Manual 4.0 Semi-analytical propagation - Historique des versions

Admin : /* Third Body */

Admin le 21 février 2018 à 14:25

Admin : /* Contents */

Admin : /* Javadoc */

Admin le 19 février 2018 à 16:21

Admin : /* Configuration: Frames and Time scales */

Admin : /* Orbits */

Admin : /* Solar radiation pressure (SRP) */

Admin : /* Solar radiation pressure (SRP) */

Admin : /* Third Body */

Admin : /* Third Body */

Admin : /* Contents */

Admin : /* Javadoc */

Admin : /* Configuration: Frames and Time scales */

Admin : /* Orbits */

Admin : /* Solar radiation pressure (SRP) */

Admin : /* Solar radiation pressure (SRP) */

Admin : /* Third Body */