GravityEngine2.KeplerPropagator Class Reference

Code to propagate Kepler orbits (ellipse, parabola, hyperbola). More...

Classes
struct	PropInfo
struct	RVT

Static Public Member Functions
static void	EvolveKeplerMassive (double t_to, ref GEPhysicsCore.GEBodies bodies, ref NativeArray< PropInfo > kpi, ref NativeArray< int > indices, int lenIndices)
	Evolves all the massive Kepler bodies to their new absolute position.
static bool	EvolveMasslessProgagators (double t_to, ref GEPhysicsCore.GEBodies bodies, ref NativeArray< PropInfo > kpi, ref NativeArray< GEPhysicsCore.PatchInfo > patchInfo, ref NativeArray< int > indices, int lenIndices, ref NativeList< GEPhysicsCore.PhysEvent > eventList, bool coRoFrame)
static void	EvolveRelative (double t, int propId, ref NativeArray< PropInfo > kpi, ref GEBodyState state)
	Version to allow direct use of a propagator in GE.
static void	FindC2C3 (double znew, out double c2new, out double c3new)
static void	ManeuverPropagator (int bodyIndex, double time, ref GEPhysicsCore.GEBodies bodies, ref NativeArray< PropInfo > kpi)
	Update the KeplerPropagator for the body at bodyIndex with the new position, velocity and time based on applying a maneuver in the Run() loop.
static int double3	RVforTime (RVT rvt, double physicsTime)

Static Public Attributes
static int	double3
static string[]	errorText = new string[] { "OK", "Time < time0", "Did not converge" }
const int	MAX_KEPLER_DEPTH = 3
const int	NOT_CONVERGED = 2
const int	PROP_OK = 0
	Evolve the orbit to the time indicated. The algorithm used requires some internal iteration but in general converges very quiclky. (All solutions to Kepler's equation use some iteration, since the equation is not closed form).
static int	status
const int	T_TOO_EARLY = 1

Detailed Description

Code to propagate Kepler orbits (ellipse, parabola, hyperbola).

This code will be called from Job in the job system so it cannot make reference to any classes, hence the implementation as a data struct and static methods.

The propagator is based on the universal variable Kepler method from Vallado. This is chosen since it has smooth hand off between ellipse, parabola and hyperbola.

RVT has two contructors, one that preserves the initial COE (which can then be retreived by e.g. orbit display code that does not care about the exact phase of the orbit (since it will be drawing the entire shape).

Member Function Documentation

EvolveKeplerMassive()

static void GravityEngine2.KeplerPropagator.EvolveKeplerMassive ( double t_to, ref GEPhysicsCore::GEBodies bodies, ref NativeArray< PropInfo > kpi, ref NativeArray< int > indices, int lenIndices )

static

Evolves all the massive Kepler bodies to their new absolute position.

This is done heirarchically, so MASSIVE1, 2, 3.

Parameters

bodies
rvtEntries
parms

EvolveRelative()

static void GravityEngine2.KeplerPropagator.EvolveRelative ( double t, int propId, ref NativeArray< PropInfo > kpi, ref GEBodyState state )

static

Version to allow direct use of a propagator in GE.

Parameters

t
propId
kpi
state

ManeuverPropagator()

static void GravityEngine2.KeplerPropagator.ManeuverPropagator ( int bodyIndex, double time, ref GEPhysicsCore::GEBodies bodies, ref NativeArray< PropInfo > kpi )

static

Update the KeplerPropagator for the body at bodyIndex with the new position, velocity and time based on applying a maneuver in the Run() loop.

Parameters

bodyIndex
time
bodies
kpi

Member Data Documentation

PROP_OK

const int GravityEngine2.KeplerPropagator.PROP_OK = 0

static

Evolve the orbit to the time indicated. The algorithm used requires some internal iteration but in general converges very quiclky. (All solutions to Kepler's equation use some iteration, since the equation is not closed form).

Universal Kepler evolution using KEPLER (algorithm 8) from Vallado, p93 Code taken from book companion site and adapted to C#/Unity.

Parameters

physicsTime
r_new	Position at the specified time (returned by ref)

---

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

• ge2/GE2/Assets/GravityEngine2/Runtime/Core/Propagators/KeplerPropagator.cs