GravityEngine2.CR3BP Class Reference

Circular Restricted Three Body Problem. More...

Classes
class	CR3BPSystemData

Public Types
enum	ReferencePoint {   NONE , PRIMARY , SECONDARY , L1 ,   L2 , L3 , L4 , L5 }
enum	TB_System {   EARTH_MOON , SUN_EARTH , SUN_MARS , MARS_PHOBIS ,   JUPITER_EUROPA , SATURN_ENCELADUS , SATURN_TITAN , CUSTOM }

Static Public Member Functions
static double3 double3 v	FrameInertialToRotating (double3 r, double3 v, double t)
static double3 double3 v	FrameRotatingToInertial (double3 r, double3 v, double t)
static void	GSBodiesSetup (TB_System cr3bp, GSBody primary, GSBody secondary)
	Configure the parameters for the GSBodies for a CR3BP system based on the default units of the GSController.
static void	InertialToRotatingVec3 (ref UnityEngine.Vector3[] r, double t)
static void	NormToSIkm (ref GEBodyState bodyState, CR3BPSystemData sysData)
	Convert normalized CR3BP state value to SI_km.
static double	RK4Step (ref GEPhysicsCore.GEPhysicsJob geJob)
static void	SIkmToNorm (ref GEBodyState bodyState, CR3BPSystemData sysData)
	Convert SIkm to normalized CR3BP dimensionless units.
static CR3BPSystemData	SystemData (TB_System cr3bpType)

Static Public Attributes
static double3	r
	Transform rotating NORMALIZED R, V to inertial R, V.

Detailed Description

Circular Restricted Three Body Problem.

Utility functions to assist in converting from the inertial coordinates into the co-rotating coordinates.

The CR3BP integrator follows the usual convention of normalizing the separation between the bodies to 1 and the total mass to one, with a mass fraction of the secondary body being mu. (Hence the primary is 1-mu).

In the corotating coordinates the CM of the system is at zero and the position of the primary is (-mu, 0, 0) and the secondary is (1-mu, 0, 0).

Unit of mass: m1 + m2 Unit of Length: d(m1, m2) Unit of Time: 2 Pi for one orbit of the secondary This results in G=1.

A good reference is 2.2 of Koon, Lo, Marsden & Ross (KLMR). Available as a free PDF at https://ross.aoe.vt.edu/books/Ross_3BodyProblem_Book_2022.pdf

Member Function Documentation

GSBodiesSetup()

static void GravityEngine2.CR3BP.GSBodiesSetup ( TB_System cr3bp, GSBody primary, GSBody secondary )

static

Configure the parameters for the GSBodies for a CR3BP system based on the default units of the GSController.

Parameters

cr3bp
primary
secondary

NormToSIkm()

static void GravityEngine2.CR3BP.NormToSIkm ( ref GEBodyState bodyState, CR3BPSystemData sysData )

static

Convert normalized CR3BP state value to SI_km.

Parameters

bodyState
fromUnits
sysData

SIkmToNorm()

static void GravityEngine2.CR3BP.SIkmToNorm ( ref GEBodyState bodyState, CR3BPSystemData sysData )

static

Convert SIkm to normalized CR3BP dimensionless units.

Parameters

bodyState
toUnits
sysData

Member Data Documentation

r

static double3 GravityEngine2.CR3BP.r

static

Transform rotating NORMALIZED R, V to inertial R, V.

See KLMR

This assumes CR3BP scaling in which the period of orbit for the secondary is 2 Pi

Parameters

r
v
t

Returns

See KLMR and then do the inversion.

This assumes CR3BP scaling in which the period of orbit for the secondary is 2 Pi

A(t)^-1 R = r

Parameters

r
v
t

Returns

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The documentation for this class was generated from the following file:

• ge2/GE2/Assets/GravityEngine2/Runtime/Core/Integrators/CR3BP.cs