sc_lambert.h File Reference

Lambert orbital element starting and ending set. More...

Classes
struct	lambert
	Lambert orbital element starting and ending set. More...
Functions
bool	Target (double t0, double tTrans, const lambert d, ml_matrix &vTrans, ml_matrix &deltaV)
	Perform targeting between two orbits.
ml_matrix	Lambert (const ml_matrix &r1, const ml_matrix &r2, double dT, int tM, double mu, double &a, double &p)
	Solves the Lambert time of flight problem using Battin's method.
double	Zeta (double x)
double	CubicRoot (double h1, double h2)

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Detailed Description

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Function Documentation

bool Target	(	double	t0,
		double	tTrans,
		const lambert	d,
		ml_matrix &	vTrans,
		ml_matrix &	deltaV
	)

Uses rv_orb_gen to propagate the first orbit to t0 and the second orbit to t0+tTrans. Chooses the long or short was based on angular momentum and computes the Lambert solution. Finally, checks for a hit Earth condition.

Parameters:

t0	Start time
tTrans	Transfer time
d	Lambert structure with two sets of orbital elements
vTrans	The resulting transfer velocities (3x2)
deltaV	The resulting delta-V's (3x2)

Returns:

A flag indicating a feasible transfer was found that doesn't hit the Earth

References lambert::el1, lambert::el2, and MU_EARTH.

ml_matrix Lambert	(	const ml_matrix &	r1,
		const ml_matrix &	r2,
		double	dT,
		int	tM,
		double	mu,
		double &	a,
		double &	p
	)

------------------------------------------------------------------------------- MATLAB Form: [vT, a, p, tol] = Lambert( r1, r2, dT, tM, tol, maxIter ) -------------------------------------------------------------------------------

Parameters:

r1	(3,1) Initial position vector
r2	(3,1) Final position vector
dT	Time between position 2 and 1
tM	direct (1) or retrograde (-1)
mu	Gravitational parameter
a	Resulting semi-major axis of the trajectory
p	Resulting parameter for the orbit

Returns:

Matrix (3,2) Transfer velocity

------------------------------------------------------------------------------- References: Battin, R. H. "An Introduction to the Mathematics and Methods of Astrodynamics", AIAA Education Series. Vallado, D. A. Fundamentals of Astrodynamics and Applications. -------------------------------------------------------------------------------

References PI.