Public Types
enum	EncounterSolutionLevel { EncounterSolutionLevel.NONE = 0, EncounterSolutionLevel.ESCAPE = 1, EncounterSolutionLevel.ORBIT_INTERSECT = 2, EncounterSolutionLevel.SOI_INTERSECT_2 = 3, EncounterSolutionLevel.SOI_INTERSECT_1 = 4 }

enum	ObjectType { ObjectType.VESSEL = 0, ObjectType.SPACE_DEBRIS = 1, ObjectType.CELESTIAL_BODIES = 2, ObjectType.UNKNOWN_MISC = 3, ObjectType.KERBAL = 4 }

enum	PatchTransitionType { PatchTransitionType.INITIAL = 0, PatchTransitionType.FINAL = 1, PatchTransitionType.ENCOUNTER = 2, PatchTransitionType.ESCAPE = 3, PatchTransitionType.MANEUVER = 4 }

Public Member Functions
	Orbit ()

	Orbit (double inc, double e, double sma, double lan, double w, double mEp, double t, CelestialBody body)

void	DrawOrbit ()

Vector3d	GetANVector ()

double	GetDTforTrueAnomaly (double tA, double wrapAfterSeconds)

double	GetEccentricAnomaly (double tA)

Vector3d	GetEccVector ()

Vector3d	GetFrameVel ()
	The velocity of the orbiting object, {AliceWorld, Sun}. More...

Vector3d	GetFrameVelAtUT (double UT)

double	GetMeanAnomaly (double E, double tA)

double	getObTAtMeanAnomaly (double M)

double	getObtAtUT (double UT)

double	getOrbitalSpeedAt (double time)

double	getOrbitalSpeedAtDistance (double d)

double	getOrbitalSpeedAtPos (Vector3d pos)

double	getOrbitalSpeedAtRelativePos (Vector3d relPos)

Vector3d	getOrbitalVelocityAtObT (double ObT)

Vector3d	getOrbitalVelocityAtUT (double UT)

Vector3d	GetOrbitNormal ()
	A unit vector normal to the plane of the orbit. NOTE: All Vector3d's returned by Orbit class functions have their y and z axes flipped. You have to flip these back to get the vectors in world coordinates. More...

Trajectory	GetPatchTrajectory (int sampleCount)

Vector3d	getPositionAtT (double T)

Vector3d	getPositionAtUT (double UT)

Vector3d	getPositionFromEccAnomaly (double E)

Vector3d	getPositionFromMeanAnomaly (double M)

Vector3d	getPositionFromTrueAnomaly (double tA)

Vector3d	getRelativePositionAtT (double T)
	Gets the predicted displacement of the orbiting object from the center of the main body at a given time since perigee passage. NOTE: All Vector3d's returned by Orbit class functions have their y and z axes flipped. You have to flip these back to get the vectors in world coordinates. More...

Vector3d	getRelativePositionAtUT (double UT)
	Gets the predicted displacement of the orbiting object from the center of the main body at a given universal time. NOTE: All Vector3d's returned by Orbit class functions have their y and z axes flipped. You have to flip these back to get the vectors in world coordinates. More...

Vector3d	getRelativePositionFromEccAnomaly (double E)

Vector3d	getRelativePositionFromMeanAnomaly (double M)

Vector3d	getRelativePositionFromTrueAnomaly (double tA)

Vector3d	GetRelativeVel ()
	The velocity of the orbiting object, {World, Primary}. More...

Vector3d	GetRotFrameVel (CelestialBody refBody)
	The velocity of a hypothetical object, located where the orbiting object is, and at rest in the ConditionallyRotating[refBody] frame, {AliceWorld, BodyCentre[refBody]}. In other words, velocity of the ConditionallyRotating[refBody] frame in the BodyCentre[refBody] frame at the position of the orbiting object (AliceWorld axes). Note: this only depends on the orbital position, not on the orbital velocity. More...

double	getTrueAnomaly (double E)

double	GetTrueAnomalyOfZupVector (Vector3d vector)

Vector3d	getTruePositionAtUT (double UT)

double	GetUTforTrueAnomaly (double tA, double wrapAfterSeconds)

Vector3d	GetVel ()
	The velocity of the orbiting object, {World, ActiveVesselPrimary}. More...

Vector3d	GetWorldSpaceVel ()
	The velocity of the orbiting object, {World, ActiveVesselPrimaryConditionallyRotating}. More...

void	Init ()

double	RadiusAtTrueAnomaly (double tA)
	The distance the orbiting object will be from the center of the main body when it reaches the given true anomaly. More...

double	solveEccentricAnomaly (double M, double ecc, double maxError, int maxIterations)

double	TrueAnomalyAtRadius (double R)
	The true anomaly at which the orbiting object will achieve the given distance from the center of the main body. More...

double	TrueAnomalyAtT (double T)

double	TrueAnomalyAtUT (double UT)

void	UpdateFromOrbitAtUT (Orbit orbit, double UT, CelestialBody toBody)

void	UpdateFromStateVectors (Vector3d pos, Vector3d vel, CelestialBody refBody, double UT)
	Updates this orbit to reflect the orbit that will be taken around the given body by an object with the given position and velocity at the given universal time. More...

void	UpdateFromUT (double UT)

Static Public Member Functions
static void	FindClosestPoints (Orbit p, Orbit s, ref double CD, ref double CCD, ref double FFp, ref double FFs, ref double SFp, ref double SFs, double epsilon, int maxIterations, ref int iterationCount)

static bool	PeApIntersects (Orbit primary, Orbit secondary, double threshold)

static double	SolveClosestApproach (Orbit p, Orbit s, ref double UT, double dT, double threshold, double MinUT, double MaxUT, double epsilon, int maxIterations, ref int iterationCount)

static bool	SolveSOI_BSP (Orbit p, Orbit s, ref double UT, double dT, double Rsoi, double MinUT, double MaxUT, double epsilon, int maxIterations, ref int iterationCount)

Public Attributes
bool	activePatch
	Whether this patch actually represents a real orbit patch in the projected flight path. Often Orbit.nextPatch for the last real will not be null, but will be some sort of bogus Orbit object. You can recognize these because activePatch will be false. More...

double	altitude

Vector3d	an

double	argumentOfPeriapsis
	The angle between the ascending node and the periapsis, in degrees. More...

double	ClAppr

double	ClEctr1

double	ClEctr2

CelestialBody	closestEncounterBody

Orbit.EncounterSolutionLevel	closestEncounterLevel

Orbit	closestEncounterPatch

double	closestTgtApprUT

double	CrAppr

bool	debug_returnFullEllipseTrajectory

Vector3	debugAN

Vector3	debugEccVec

Vector3	debugH

Vector3	debugPos

Vector3	debugVel

double	E

double	eccentricAnomaly
	A quantity used in the math describing Keplerian orbits; Google it. More...

double	eccentricity
	The eccentricity of the orbit. More...

Vector3d	eccVec
	A vector that points toward periapsis, with mangitude equal to the eccentricity. NOTE: All Vector3d's returned by Orbit class functions have their y and z axes flipped. You have to flip these back to get the vectors in world coordinates. More...

double	EndUT
	The universal time at which this patch ends. More...

double	epoch
	A special UT at which the parameters of the Orbit are defined. See meanAnomalyAtEpoch. More...

double	FEVp

double	FEVs

double	fromE

double	fromV

Vector3d	h
	The specific orbital angular momentum More...

double	inclination
	The inclination of this orbit with respect to the equator of the central body in degrees More...

double	LAN
	The longitude of the ascending node of the orbit, in degrees. The LAN is the angle between the ascending node and Planetarium.right, as viewed along Planetarium.up. More...

double	mag

double	meanAnomaly
	Mean anomaly is the fraction of the orbit that has been completed, measured starting from the periapsis, multiplied by 2π. Look it up. More...

double	meanAnomalyAtEpoch
	The mean anomaly of the orbit at the special UT given by Orbit.epoch. More...

double	nearestTT

Orbit	nextPatch

double	nextTT

Orbit.ObjectType	objectType

double	ObT
	Time since periapsis, in seconds. More...

double	ObTAtEpoch
	The value of ObT at the universal time given by epoch. More...

double	orbitalEnergy

double	orbitalSpeed

double	orbitPercent
	Equal to More...

Orbit.PatchTransitionType	patchEndTransition
	How the next patch follows onto this one, or FINAL if there is no patch after this one. More...

Orbit.PatchTransitionType	patchStartTransition

double	period
	The period of the orbit, in seconds. More...

Vector3d	pos
	The position of the orbiting object, {AliceWorld, Primary}. More...

Orbit	previousPatch

double	radius

CelestialBody	referenceBody
	The body orbited. More...

double	sampleInterval

Vector3d	secondaryPosAtTransition1

Vector3d	secondaryPosAtTransition2

double	semiMajorAxis
	The semi-major axis of the orbit, in meters. Equal to (PeR + ApR)/2 More...

double	SEVp

double	SEVs

double	StartUT

double	timeToAp
	The time until the object will reach apoapsis, in seconds. More...

double	timeToPe
	The time unti lthe object will reach periapsis, in seconds. More...

double	timeToTransition1

double	timeToTransition2

double	toE

double	toV

double	trueAnomaly

double	UTappr

double	UTsoi

double	V

Vector3d	vel
	The velocity of the orbiting object, {AliceWorld, Primary}. More...

Properties
double	ApA `[get]`
	The apoapsis of the orbit in meters, measured from sea level. More...

double	ApR `[get]`
	The apoapsis of the orbit in meters, measured from the center of the main body. More...

double	PeA `[get]`
	The periapsis of the orbit in meters, measured from sea level. More...

double	PeR `[get]`
	The periapsis of the orbit in meters, measured from the center of the main body. More...

double	semiLatusRectum `[get]`
	A property of ellipses, parabolas and hyperbolas; Google it. More...

double	semiMinorAxis `[get]`
	A property of ellipses; Google it. More...

Detailed Description

An Orbit class represents a Keplerian orbit. Each Vessel and each CelestialBody has an Orbit. CelestialBodies and on-rails Vessels follow their Orbits exactly. Off-rails vessels (the active vessel and any nearby vessels) do not follow their orbits exactly; instead their motion is computed frame-by-frame from the forces acting on them.

A patched consics trajectory consists of a series of Orbits, called patches.

This class uses multiple axes and reference frames to describe positions and velocities.

We call the choices of axes

World: world coordinates. Left-handed.
AliceWorld: world coordinates with the y and z axes flipped. Right-handed.

We call the reference frames used

BodyCentre[foo]: position and velocity relative to the centre of the CelestialBody |foo|.
BodyRotating[foo]: position relative to the centre of the CelestialBody |foo|, velocity relative to its rotating surface.
ConditionallyRotating[foo]: If |foo.inverseRotation|, BodyRotating[foo], otherwise BodyCentre[foo].
Sun: BodyCentre[Planetarium.fetch.Sun].
Primary: BodyCentre[this.referenceBody].
ActiveVesselPrimary: If the active vessel is not null, BodyCentre[FlightGlobals.ActiveVessel.orbit.referenceBody], otherwise Sun.
ActiveVesselPrimaryConditionallyRotating: If the active vessel is not null, ConditionallyRotating[FlightGlobals.ActiveVessel.orbit.referenceBody], otherwise Sun.>

We use the concise notation {Axes, Frame} for describing the reference frame and axes used.

Member Enumeration Documentation

enum Orbit.EncounterSolutionLevel

Enumerator
NONE
ESCAPE
ORBIT_INTERSECT
SOI_INTERSECT_2
SOI_INTERSECT_1

enum Orbit.ObjectType

Enumerator
VESSEL
SPACE_DEBRIS
CELESTIAL_BODIES
UNKNOWN_MISC
KERBAL

enum Orbit.PatchTransitionType

Enumerator
INITIAL
FINAL
ENCOUNTER
ESCAPE
MANEUVER

Constructor & Destructor Documentation

Orbit.Orbit ( )

Orbit.Orbit	(	double	inc,
		double	e,
		double	sma,
		double	lan,
		double	w,
		double	mEp,
		double	t,
		CelestialBody	body
	)

Member Function Documentation

void Orbit.DrawOrbit ( )

static void Orbit.FindClosestPoints	(	Orbit	p,
		Orbit	s,
		ref double	CD,
		ref double	CCD,
		ref double	FFp,
		ref double	FFs,
		ref double	SFp,
		ref double	SFs,
		double	epsilon,
		int	maxIterations,
		ref int	iterationCount
	)

static

Vector3d Orbit.GetANVector ( )

double Orbit.GetDTforTrueAnomaly	(	double	tA,
		double	wrapAfterSeconds
	)

double Orbit.GetEccentricAnomaly ( double tA )

Vector3d Orbit.GetEccVector ( )

Vector3d Orbit.GetFrameVel ( )

The velocity of the orbiting object, {AliceWorld, Sun}.

Vector3d Orbit.GetFrameVelAtUT ( double UT )

double Orbit.GetMeanAnomaly	(	double	E,
		double	tA
	)

double Orbit.getObTAtMeanAnomaly ( double M )

double Orbit.getObtAtUT ( double UT )

double Orbit.getOrbitalSpeedAt ( double time )

double Orbit.getOrbitalSpeedAtDistance ( double d )

double Orbit.getOrbitalSpeedAtPos ( Vector3d pos )

double Orbit.getOrbitalSpeedAtRelativePos ( Vector3d relPos )

Vector3d Orbit.getOrbitalVelocityAtObT ( double ObT )

Vector3d Orbit.getOrbitalVelocityAtUT ( double UT )

Vector3d Orbit.GetOrbitNormal ( )

A unit vector normal to the plane of the orbit. NOTE: All Vector3d's returned by Orbit class functions have their y and z axes flipped. You have to flip these back to get the vectors in world coordinates.

Returns: A unit normal vector.

Trajectory Orbit.GetPatchTrajectory ( int sampleCount )

Vector3d Orbit.getPositionAtT ( double T )

Vector3d Orbit.getPositionAtUT ( double UT )

Vector3d Orbit.getPositionFromEccAnomaly ( double E )

Vector3d Orbit.getPositionFromMeanAnomaly ( double M )

Vector3d Orbit.getPositionFromTrueAnomaly ( double tA )

Vector3d Orbit.getRelativePositionAtT ( double T )

Gets the predicted displacement of the orbiting object from the center of the main body at a given time since perigee passage. NOTE: All Vector3d's returned by Orbit class functions have their y and z axes flipped. You have to flip these back to get the vectors in world coordinates.

Parameters

T	Time since perigee passage (seconds)

Returns: Position relative to the main body (YZ flipped)

Vector3d Orbit.getRelativePositionAtUT ( double UT )

Gets the predicted displacement of the orbiting object from the center of the main body at a given universal time. NOTE: All Vector3d's returned by Orbit class functions have their y and z axes flipped. You have to flip these back to get the vectors in world coordinates.

Parameters

UT	A univeral time.

Returns: Position relative to the main body (YZ flipped)

Vector3d Orbit.getRelativePositionFromEccAnomaly ( double E )

Vector3d Orbit.getRelativePositionFromMeanAnomaly ( double M )

Vector3d Orbit.getRelativePositionFromTrueAnomaly ( double tA )

Vector3d Orbit.GetRelativeVel ( )

The velocity of the orbiting object, {World, Primary}.

Vector3d Orbit.GetRotFrameVel ( CelestialBody refBody )

The velocity of a hypothetical object, located where the orbiting object is, and at rest in the ConditionallyRotating[refBody] frame, {AliceWorld, BodyCentre[refBody]}. In other words, velocity of the ConditionallyRotating[refBody] frame in the BodyCentre[refBody] frame at the position of the orbiting object (AliceWorld axes). Note: this only depends on the orbital position, not on the orbital velocity.

double Orbit.getTrueAnomaly ( double E )

double Orbit.GetTrueAnomalyOfZupVector ( Vector3d vector )

Vector3d Orbit.getTruePositionAtUT ( double UT )

double Orbit.GetUTforTrueAnomaly	(	double	tA,
		double	wrapAfterSeconds
	)

Vector3d Orbit.GetVel ( )

The velocity of the orbiting object, {World, ActiveVesselPrimary}.

Vector3d Orbit.GetWorldSpaceVel ( )

The velocity of the orbiting object, {World, ActiveVesselPrimaryConditionallyRotating}.

void Orbit.Init ( )

static bool Orbit.PeApIntersects	(	Orbit	primary,
		Orbit	secondary,
		double	threshold
	)

static

double Orbit.RadiusAtTrueAnomaly ( double tA )

The distance the orbiting object will be from the center of the main body when it reaches the given true anomaly.

Parameters

tA	True anomaly (in degrees)

Returns: Distance from the main body's center, in meters

static double Orbit.SolveClosestApproach	(	Orbit	p,
		Orbit	s,
		ref double	UT,
		double	dT,
		double	threshold,
		double	MinUT,
		double	MaxUT,
		double	epsilon,
		int	maxIterations,
		ref int	iterationCount
	)

static

double Orbit.solveEccentricAnomaly	(	double	M,
		double	ecc,
		double	maxError,
		int	maxIterations
	)

static bool Orbit.SolveSOI_BSP	(	Orbit	p,
		Orbit	s,
		ref double	UT,
		double	dT,
		double	Rsoi,
		double	MinUT,
		double	MaxUT,
		double	epsilon,
		int	maxIterations,
		ref int	iterationCount
	)

static

double Orbit.TrueAnomalyAtRadius ( double R )

The true anomaly at which the orbiting object will achieve the given distance from the center of the main body.

Parameters

R	Distance from the center of the main body, in meters.

Returns: True anomaly, in radians.

double Orbit.TrueAnomalyAtT ( double T )

double Orbit.TrueAnomalyAtUT ( double UT )

void Orbit.UpdateFromOrbitAtUT	(	Orbit	orbit,
		double	UT,
		CelestialBody	toBody
	)

void Orbit.UpdateFromStateVectors	(	Vector3d	pos,
		Vector3d	vel,
		CelestialBody	refBody,
		double	UT
	)

Updates this orbit to reflect the orbit that will be taken around the given body by an object with the given position and velocity at the given universal time.

Parameters

pos	The initial position of the object RELATIVE TO refBody at UT (YZ flipped)
vel	The initial velocity of the object (YZ flipped)
refBody	The main body
UT	The universal time at which to start the orbit.

void Orbit.UpdateFromUT ( double UT )

Member Data Documentation

bool Orbit.activePatch

Whether this patch actually represents a real orbit patch in the projected flight path. Often Orbit.nextPatch for the last real will not be null, but will be some sort of bogus Orbit object. You can recognize these because activePatch will be false.

double Orbit.altitude

Vector3d Orbit.an

double Orbit.argumentOfPeriapsis

The angle between the ascending node and the periapsis, in degrees.

double Orbit.ClAppr

double Orbit.ClEctr1

double Orbit.ClEctr2

CelestialBody Orbit.closestEncounterBody

Orbit.EncounterSolutionLevel Orbit.closestEncounterLevel

Orbit Orbit.closestEncounterPatch

double Orbit.closestTgtApprUT

double Orbit.CrAppr

bool Orbit.debug_returnFullEllipseTrajectory

Vector3 Orbit.debugAN

Vector3 Orbit.debugEccVec

Vector3 Orbit.debugH

Vector3 Orbit.debugPos

Vector3 Orbit.debugVel

double Orbit.E

double Orbit.eccentricAnomaly

A quantity used in the math describing Keplerian orbits; Google it.

double Orbit.eccentricity

The eccentricity of the orbit.

Vector3d Orbit.eccVec

A vector that points toward periapsis, with mangitude equal to the eccentricity. NOTE: All Vector3d's returned by Orbit class functions have their y and z axes flipped. You have to flip these back to get the vectors in world coordinates.

double Orbit.EndUT

The universal time at which this patch ends.

double Orbit.epoch

A special UT at which the parameters of the Orbit are defined. See meanAnomalyAtEpoch.

double Orbit.FEVp

double Orbit.FEVs

double Orbit.fromE

double Orbit.fromV

Vector3d Orbit.h

The specific orbital angular momentum

double Orbit.inclination

The inclination of this orbit with respect to the equator of the central body in degrees

double Orbit.LAN

The longitude of the ascending node of the orbit, in degrees. The LAN is the angle between the ascending node and Planetarium.right, as viewed along Planetarium.up.

double Orbit.mag

double Orbit.meanAnomaly

Mean anomaly is the fraction of the orbit that has been completed, measured starting from the periapsis, multiplied by 2π. Look it up.

double Orbit.meanAnomalyAtEpoch

The mean anomaly of the orbit at the special UT given by Orbit.epoch.

double Orbit.nearestTT

Orbit Orbit.nextPatch

double Orbit.nextTT

Orbit.ObjectType Orbit.objectType

double Orbit.ObT

Time since periapsis, in seconds.

double Orbit.ObTAtEpoch

The value of ObT at the universal time given by epoch.

double Orbit.orbitalEnergy

double Orbit.orbitalSpeed

double Orbit.orbitPercent

Equal to

>ObT / period

Orbit.PatchTransitionType Orbit.patchEndTransition

How the next patch follows onto this one, or FINAL if there is no patch after this one.

Orbit.PatchTransitionType Orbit.patchStartTransition

double Orbit.period

The period of the orbit, in seconds.

Vector3d Orbit.pos

The position of the orbiting object, {AliceWorld, Primary}.

Orbit Orbit.previousPatch

double Orbit.radius

CelestialBody Orbit.referenceBody

The body orbited.

double Orbit.sampleInterval

Vector3d Orbit.secondaryPosAtTransition1

Vector3d Orbit.secondaryPosAtTransition2

double Orbit.semiMajorAxis

The semi-major axis of the orbit, in meters. Equal to (PeR + ApR)/2

double Orbit.SEVp

double Orbit.SEVs

double Orbit.StartUT

double Orbit.timeToAp

The time until the object will reach apoapsis, in seconds.

double Orbit.timeToPe

The time unti lthe object will reach periapsis, in seconds.

double Orbit.timeToTransition1

double Orbit.timeToTransition2

double Orbit.toE

double Orbit.toV

double Orbit.trueAnomaly

double Orbit.UTappr

double Orbit.UTsoi

double Orbit.V

Vector3d Orbit.vel

The velocity of the orbiting object, {AliceWorld, Primary}.

Property Documentation

double Orbit.ApA

get

The apoapsis of the orbit in meters, measured from sea level.

double Orbit.ApR

get

The apoapsis of the orbit in meters, measured from the center of the main body.

double Orbit.PeA

get

The periapsis of the orbit in meters, measured from sea level.

double Orbit.PeR

get

The periapsis of the orbit in meters, measured from the center of the main body.

double Orbit.semiLatusRectum

get

A property of ellipses, parabolas and hyperbolas; Google it.

double Orbit.semiMinorAxis

get

A property of ellipses; Google it.

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

src/Orbit.cs

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Properties

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

Property Documentation