Float Ambiguity Resolution

Functions
void	assign_dd_obs_cov (u8 num_dds, double phase_var, double code_var, double *dd_obs_cov)
void	assign_de_mtx (u8 num_sats, sdiff_t *sats_with_ref_first, double ref_ecef[3], double *DE)
void	assign_H_prime (u8 res_dim, u8 constraint_dim, u8 num_dds, double *Q, double *U_inv, double *H_prime)
void	assign_phase_obs_null_basis (u8 num_dds, double *DE_mtx, double *q)
void	assign_residual_obs_cov (u8 num_dds, double phase_var, double code_var, double *q, double *r_cov)
void	assign_simple_sig (u8 num_dds, double var, double *simple_cov)
void	assign_state_rebase_mtx (u8 num_sats, u8 *old_prns, u8 *new_prns, double *rebase_mtx)
void	diffuse_state (nkf_t *kf)
s32	find_index_of_element_in_u8s (u32 num_elements, u8 x, u8 *list)
void	get_kf_matrices (u8 num_sdiffs, sdiff_t *sdiffs_with_ref_first, double ref_ecef[3], double phase_var, double code_var, double *null_basis_Q, double *U_inv, double *D, double *H_prime)
void	incorporate_obs (nkf_t *kf, double *decor_obs)
void	incorporate_scalar_measurement (u32 state_dim, double *h, double R, double *U, double *D, double *k)
void	initialize_state (nkf_t *kf, double *dd_measurements, double init_var)
void	invert_U (u8 res_dim, double *U)
void	least_squares_solve_b (nkf_t *kf, sdiff_t *sdiffs_with_ref_first, double *dd_measurements, double ref_ecef[3], double b[3])
void	least_squares_solve_b_external_ambs (u8 num_dds_u8, double *ambs, sdiff_t *sdiffs_with_ref_first, double *dd_measurements, double ref_ecef[3], double b[3])
void	make_residual_measurements (nkf_t *kf, double *measurements, double *resid_measurements)
void	nkf_state_inclusion (nkf_t *kf, u8 num_old_non_ref_sats, u8 num_new_non_ref_sats, u8 *ndx_of_old_sat_in_new, double int_init_var)
void	nkf_state_projection (nkf_t *kf, u8 num_old_non_ref_sats, u8 num_new_non_ref_sats, u8 *ndx_of_new_sat_in_old)
void	nkf_update (nkf_t *kf, double *measurements)
void	QR_part1 (integer m, integer n, double *A, double *tau)
void	QR_part2 (integer m, integer n, double *A, double *tau)
void	rebase_covariance_sigma (double *state_cov, u8 num_sats, u8 *old_prns, u8 *new_prns)
void	rebase_covariance_udu (double *state_cov_U, double *state_cov_D, u8 num_sats, u8 *old_prns, u8 *new_prns)
void	rebase_mean_N (double *mean, u8 num_sats, u8 *old_prns, u8 *new_prns)
void	rebase_nkf (nkf_t *kf, u8 num_sats, u8 *old_prns, u8 *new_prns)
void	set_nkf (nkf_t *kf, double amb_drift_var, double phase_var, double code_var, double amb_init_var, u8 num_sdiffs, sdiff_t *sdiffs_with_ref_first, double *dd_measurements, double ref_ecef[3])
void	set_nkf_matrices (nkf_t *kf, double phase_var, double code_var, u8 num_sdiffs, sdiff_t *sdiffs_with_ref_first, double ref_ecef[3])

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Detailed Description

Preliminary integer ambiguity estimation with a Kalman Filter.

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Function Documentation

void assign_dd_obs_cov	(	u8	num_dds,
		double	phase_var,
		double	code_var,
		double *	dd_obs_cov
	)

Definition at line 561 of file amb_kf.c.

void assign_de_mtx	(	u8	num_sats,
		sdiff_t *	sats_with_ref_first,
		double	ref_ecef[3],
		double *	DE
	)

Definition at line 241 of file amb_kf.c.

void assign_H_prime	(	u8	res_dim,
		u8	constraint_dim,
		u8	num_dds,
		double *	Q,
		double *	U_inv,
		double *	H_prime
	)

Definition at line 652 of file amb_kf.c.

void assign_phase_obs_null_basis	(	u8	num_dds,
		double *	DE_mtx,
		double *	q
	)

Definition at line 537 of file amb_kf.c.

void assign_residual_obs_cov	(	u8	num_dds,
		double	phase_var,
		double	code_var,
		double *	q,
		double *	r_cov
	)

Definition at line 579 of file amb_kf.c.

void assign_simple_sig	(	u8	num_dds,
		double	var,
		double *	simple_cov
	)

Definition at line 630 of file amb_kf.c.

void assign_state_rebase_mtx	(	u8	num_sats,
		u8 *	old_prns,
		u8 *	new_prns,
		double *	rebase_mtx
	)

Definition at line 799 of file amb_kf.c.

void diffuse_state

(

nkf_t *

kf

)

Definition at line 203 of file amb_kf.c.

s32 find_index_of_element_in_u8s	(	u32	num_elements,
		u8	x,
		u8 *	list
	)

Definition at line 768 of file amb_kf.c.

void get_kf_matrices	(	u8	num_sdiffs,
		sdiff_t *	sdiffs_with_ref_first,
		double	ref_ecef[3],
		double	phase_var,
		double	code_var,
		double *	null_basis_Q,
		double *	U_inv,
		double *	D,
		double *	H_prime
	)

Definition at line 685 of file amb_kf.c.

void incorporate_obs	(	nkf_t *	kf,
		double *	decor_obs
	)

In place updating of the state mean and covariances to use the (decorrelated) observations This is directly from section 10.2.1 of Gibbs [1]

Definition at line 155 of file amb_kf.c.

void incorporate_scalar_measurement	(	u32	state_dim,
		double *	h,
		double	R,
		double *	U,
		double *	D,
		double *	k
	)

In place updating of the state cov and k vec using a scalar observation This is from section 10.2.1 of Gibbs [1], with some extra logic for handling singular matrices, dictating that zeros from cov_D dominate.

Definition at line 43 of file amb_kf.c.

void initialize_state	(	nkf_t *	kf,
		double *	dd_measurements,
		double	init_var
	)

Definition at line 487 of file amb_kf.c.

void invert_U	(	u8	res_dim,
		double *	U
	)

Definition at line 619 of file amb_kf.c.

void least_squares_solve_b	(	nkf_t *	kf,
		sdiff_t *	sdiffs_with_ref_first,
		double *	dd_measurements,
		double	ref_ecef[3],
		double	b[3]
	)

A least squares solution for baseline from phases using the KF state. This uses the current state of the KF and a set of phase observations to solve for the current baseline.

Parameters:

kf	The Kalman filter struct.
sdiffs_with_ref_first	A list of sdiffs. The first in the list must be the reference sat of the KF, and the rest must correspond to the KF's DD amb estimates' sats.
dd_measurements	A vector of carrier phases. They must be double differenced and ordered according to the sdiffs and KF's sats (which must match each other).
ref_ecef	The reference position in ECEF frame, for computing the sat direction vectors.
b	The output baseline in meters.

Definition at line 351 of file amb_kf.c.

void least_squares_solve_b_external_ambs	(	u8	num_dds_u8,
		double *	ambs,
		sdiff_t *	sdiffs_with_ref_first,
		double *	dd_measurements,
		double	ref_ecef[3],
		double	b[3]
	)

Definition at line 423 of file amb_kf.c.

void make_residual_measurements	(	nkf_t *	kf,
		double *	measurements,
		double *	resid_measurements
	)

Definition at line 190 of file amb_kf.c.

void nkf_state_inclusion	(	nkf_t *	kf,
		u8	num_old_non_ref_sats,
		u8	num_new_non_ref_sats,
		u8 *	ndx_of_old_sat_in_new,
		double	int_init_var
	)

Definition at line 889 of file amb_kf.c.

void nkf_state_projection	(	nkf_t *	kf,
		u8	num_old_non_ref_sats,
		u8	num_new_non_ref_sats,
		u8 *	ndx_of_new_sat_in_old
	)

Definition at line 859 of file amb_kf.c.

void nkf_update	(	nkf_t *	kf,
		double *	measurements
	)

In place updating of the state mean and covariance. Modifies measurements.

Definition at line 213 of file amb_kf.c.

void QR_part1	(	integer	m,
		integer	n,
		double *	A,
		double *	tau
	)

Definition at line 499 of file amb_kf.c.

void QR_part2	(	integer	m,
		integer	n,
		double *	A,
		double *	tau
	)

Definition at line 520 of file amb_kf.c.

void rebase_covariance_sigma	(	double *	state_cov,
		u8	num_sats,
		u8 *	old_prns,
		u8 *	new_prns
	)

Definition at line 819 of file amb_kf.c.

void rebase_covariance_udu	(	double *	state_cov_U,
		double *	state_cov_D,
		u8	num_sats,
		u8 *	old_prns,
		u8 *	new_prns
	)

Definition at line 843 of file amb_kf.c.

void rebase_mean_N	(	double *	mean,
		u8	num_sats,
		u8 *	old_prns,
		u8 *	new_prns
	)

Definition at line 778 of file amb_kf.c.

void rebase_nkf	(	nkf_t *	kf,
		u8	num_sats,
		u8 *	old_prns,
		u8 *	new_prns
	)

Definition at line 853 of file amb_kf.c.

void set_nkf	(	nkf_t *	kf,
		double	amb_drift_var,
		double	phase_var,
		double	code_var,
		double	amb_init_var,
		u8	num_sdiffs,
		sdiff_t *	sdiffs_with_ref_first,
		double *	dd_measurements,
		double	ref_ecef[3]
	)

Definition at line 724 of file amb_kf.c.

void set_nkf_matrices	(	nkf_t *	kf,
		double	phase_var,
		double	code_var,
		u8	num_sdiffs,
		sdiff_t *	sdiffs_with_ref_first,
		double	ref_ecef[3]
	)

Definition at line 751 of file amb_kf.c.