WsfOrbitalTargeting Class Reference

A class that can compute solutions to the targeting problem. More...

#include <WsfOrbitalTargeting.hpp>

Public Member Functions
	WsfOrbitalTargeting (const UtCalendar &aTime, UtOrbitalPropagatorBase &aInterceptorProp, const wsf::space::OrbitalTargetPoint &aTarget)
	WsfOrbitalTargeting (const UtCalendar &aTime, UtOrbitalPropagatorBase &aInterceptorProp, const wsf::space::OrbitalTargetPoint &aTarget, bool aAllowHyperbolic, bool aAllowEarthHit)
	WsfOrbitalTargeting (const WsfOrbitalTargeting &aOther)=delete
	WsfOrbitalTargeting (WsfOrbitalTargeting &&)=default
	~WsfOrbitalTargeting ()=default
UtLambertProblem::Result	MinimizeDeltaV (double aDtMax, double aDvMax, bool aRendezvous, double aTimeTolerance, double &aDt, double &aDv) const
UtLambertProblem::Result	MinimizeDeltaT (double aDtMax, double aDvMax, bool aRendezvous, double aTimeTolerance, double &aDt, double &aDv) const
UtLambertProblem::Result	MinimizeCost (const wsf::space::OrbitalTargetingCost &aCost, double aDtMax, double aDvMax, bool aRendezvous, double aTimeTolerance, double &aDt, double &aDv) const
UtLambertProblem::Result	Solve (double aDt, bool aRendezvous, double &aDeltaV) const
UtLambertProblem::Result	Solve (double aDt, UtVec3d &aDeltaV_Intercept, UtVec3d &aDeltaV_Rendezvous) const
double	GetTolerance () const
void	SetTolerance (double aTolerance)

Static Public Member Functions
static bool	GoShortWay (const UtVec3d &aLocationInterceptor, const UtVec3d &aVelocityInterceptor, const UtVec3d &aLocationTarget)

Detailed Description

A class that can compute solutions to the targeting problem.

Constructor & Destructor Documentation

WsfOrbitalTargeting() [1/4]

WsfOrbitalTargeting::WsfOrbitalTargeting	(	const UtCalendar &	aTime,
		UtOrbitalPropagatorBase &	aInterceptorProp,
		const wsf::space::OrbitalTargetPoint &	aTarget )

Referenced by WsfOrbitalTargeting(), and WsfOrbitalTargeting().

WsfOrbitalTargeting() [2/4]

WsfOrbitalTargeting::WsfOrbitalTargeting	(	const UtCalendar &	aTime,
		UtOrbitalPropagatorBase &	aInterceptorProp,
		const wsf::space::OrbitalTargetPoint &	aTarget,
		bool	aAllowHyperbolic,
		bool	aAllowEarthHit )

Construct the object with the option of relaxing solution constraints. The constructor allows users to explicitly allow for solutions that have transfer orbits that are hyperbolic, or which intersect the Earth.

Parameters

aTime	The time at which to begin the targeting operation.
aInterceptorProp	A propagator representing the motion of the intercepting spacecraft.
aTarget	A target point to be intercepted.
aAllowHyperbolic	Indicates if hyperbolic transfer orbits are allowed.
aAllowEarthHit	Indicates if Earth intersecting transfer orbits are allowed.

WsfOrbitalTargeting() [3/4]

WsfOrbitalTargeting::WsfOrbitalTargeting ( const WsfOrbitalTargeting & aOther )

delete

References WsfOrbitalTargeting().

WsfOrbitalTargeting() [4/4]

WsfOrbitalTargeting::WsfOrbitalTargeting ( WsfOrbitalTargeting && )

default

References WsfOrbitalTargeting().

~WsfOrbitalTargeting()

WsfOrbitalTargeting::~WsfOrbitalTargeting ( )

default

References GoShortWay(), MinimizeCost(), MinimizeDeltaT(), MinimizeDeltaV(), and Solve().

Member Function Documentation

GetTolerance()

double WsfOrbitalTargeting::GetTolerance ( ) const

inline

GoShortWay()

bool WsfOrbitalTargeting::GoShortWay ( const UtVec3d & aLocationInterceptor, const UtVec3d & aVelocityInterceptor, const UtVec3d & aLocationTarget )

static

Decide if the Lambert solution should proceed the short or long way This is taken from Vallado, p. 506.

Parameters

aLocationInterceptor	The ECI location of the interceptor
aVelocityInterceptor	The ECI velocity of the interceptor
aLocationTarget	The ECI location of the target.

Returns

true if the short way is to be taken; false if the long way is to be taken.

Referenced by Solve(), and ~WsfOrbitalTargeting().

MinimizeCost()

UtLambertProblem::Result WsfOrbitalTargeting::MinimizeCost	(	const wsf::space::OrbitalTargetingCost &	aCost,
		double	aDtMax,
		double	aDvMax,
		bool	aRendezvous,
		double	aTimeTolerance,
		double &	aDt,
		double &	aDv ) const

Solve the targeting problem to minimize the provided cost for the transfer. This solution will impose a number of conditions on the solution. They include those of the LambertUniversal function, as well as that the maximum allowed time is not exceeded, and that the solution can be accomplished without exceeding the provided aDvMax. Unless the user of this object explicitly allows it during construction, solutions may not have transfer orbits that are hyperbolic, or which intersect the Earth.

Parameters

	aCost	The CostFunction used to define the optimum solution.
	aDtMax	The maximum allowable targeting solution time.
	aDvMax	The maximum allowable targeting delta v for the solution.
	aRendezvous	Indicates if this targeting is a rendezvous.
	aTimeTolerance	The desired precision in seconds of the solution (i.e., valid to within aTimeTolerance seconds). A value of <=1E-4 s will generally provide an error of approximately one meter or less.
[out]	aDt	The transit time of the minimum delta v solution.
[out]	aDv	The minimum delta v.

Returns

true if the solution satisfies the imposed constraints; false otherwise.

Referenced by MinimizeDeltaV(), and ~WsfOrbitalTargeting().

MinimizeDeltaT()

UtLambertProblem::Result WsfOrbitalTargeting::MinimizeDeltaT	(	double	aDtMax,
		double	aDvMax,
		bool	aRendezvous,
		double	aTimeTolerance,
		double &	aDt,
		double &	aDv ) const

Solve the targeting problem to minimize delta t of the transfer. This solution will impose a number of conditions on the solution. They include those of the LambertUniversal function, as well as that the maximum allowed delta t is not exceeded, and that the solution can be accomplished without exceeding the provided aDvMax. Unless the user of this object explicitly allows it during construction, solutions may not have transfer orbits that intersect the Earth.

Parameters

	aDtMax	The maximum allowable targeting solution time.
	aDvMax	The maximum allowable targeting delta v for the solution.
	aRendezvous	Indicates if this targeting is a rendezvous.
	aTimeTolerance	The desired precision in seconds of the solution (i.e., there is no earlier constrained solution to within aTimeTolerance).
[out]	aDt	The minimum time of the solution.
[out]	aDv	The delta v of the minimum time solution.

Returns

The result of the solution of the targeting problem for the minimum time solution.

References Solve().

Referenced by ~WsfOrbitalTargeting().

MinimizeDeltaV()

UtLambertProblem::Result WsfOrbitalTargeting::MinimizeDeltaV	(	double	aDtMax,
		double	aDvMax,
		bool	aRendezvous,
		double	aTimeTolerance,
		double &	aDt,
		double &	aDv ) const

Solve the targeting problem to minimize delta V of the transfer. This solution will impose a number of conditions on the solution. They include those of the LambertUniversal function, as well as that the maximum allowed time is not exceeded, and that the solution can be accomplished without exceeding the provided aDvMax. Unless the user of this object explicitly allows it during construction, solutions may not have transfer orbits that intersect the central body.

Parameters

	aDtMax	The maximum allowable targeting solution time.
	aDvMax	The maximum allowable targeting delta v for the solution.
	aRendezvous	Indicates if this targeting is a rendezvous.
	aTimeTolerance	The desired precision in seconds of the solution (i.e., valid to within aTimeTolerance seconds). A value of <=1E-4 s will generally provide an error of approximately one meter or less.
[out]	aDt	The transit time of the minimum delta v solution.
[out]	aDv	The minimum delta v.

Returns

The results of the optimal delta-v solution.

References MinimizeCost().

Referenced by ~WsfOrbitalTargeting().

SetTolerance()

void WsfOrbitalTargeting::SetTolerance ( double aTolerance )

inline

Referenced by WsfConjunctionInput::ComputeSolution().

Solve() [1/2]

UtLambertProblem::Result WsfOrbitalTargeting::Solve	(	double	aDt,
		bool	aRendezvous,
		double &	aDeltaV ) const

Solve the targeting problem. This will solve a single instance of the targeting problem for a given time to intercept, aDt. Unless the user allows for it during construction of this object, this method will return false if the resulting solution intersects the Earth on the transfer orbit. This is essentially Algorithm 61 from Vallado (pp. 503-504).

Parameters

	aDt	The time of the targeting solution.
	aRendezvous	Indicates if the solution is for a rendezvous.
[out]	aDeltaV	The resulting delta V for the solution.

Returns

The results of the solution of the targeting problem.

References Solve().

Referenced by WsfConjunctionInput::ComputeSolution(), MinimizeDeltaT(), Solve(), and ~WsfOrbitalTargeting().

Solve() [2/2]

UtLambertProblem::Result WsfOrbitalTargeting::Solve	(	double	aDt,
		UtVec3d &	aDeltaV_Intercept,
		UtVec3d &	aDeltaV_Rendezvous ) const

Solve the targeting problem. This will solve a single instance of the targeting problem for a given time to intercept, aDt. Unless the user allows for it during construction of this object, this method will return false if the resulting solution is hyperbolic, or if it intersects the Earth on the transfer orbit. This is essentially Algorithm 61 from Vallado (pp. 503-504). This routine computes both vector delta-V values; the caller is responsible for including the rendezvous portion if needed.

Parameters

	aDt	The time of the targeting solution.
[out]	aDeltaV_Intercept	The delta V vector for the intercept portion of the maneuver.
[out]	aDeltaV_Rendezvous	The delta V vector for the rendezvous portion of the maneuver.

Returns

The results of the targeting problem.

References GoShortWay().

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

• WsfOrbitalTargeting.hpp
• WsfOrbitalTargeting.cpp