#include <math.h>
#include <string.h>
#include <cblas.h>
#include <stdio.h>
#include "constants.h"
#include "stupid_filter.h"
#include "amb_kf.h"
#include "linear_algebra.h"
#include <lapacke.h>

Include dependency graph for stupid_filter.c:

Functions
void	amb_from_baseline (u8 num_sats, double DE, double dd_meas, double b[3], s32 *N)
void	init_stupid_filter (stupid_filter_state_t s, u8 num_sats, sdiff_t sdiffs, double *dd_meas, double b[3], double ref_ecef[3])
u8	intersect_o_tron (u8 num_sats1, u8 num_sats2, u8 sats1, sdiff_t sdiffs, double dd_meas, sdiff_t intersection_sats, double intersection_dd_meas, s32 N, s32 *intersection_N)
void	lesq_solution (u8 num_dds, double dd_meas, s32 N, double DE, double b[3], double resid)
static void	rebase_N (s32 N, u8 num_sats, u8 old_prns, u8 *new_prns)
void	rebase_stupid_filter (stupid_filter_state_t s, u8 num_sats, u8 old_prns, u8 *new_prns)
void	update_sats_stupid_filter (stupid_filter_state_t s, u8 num_old, u8 old_prns, u8 num_new, sdiff_t sdiffs, double dd_meas, double ref_ecef[3])
void	update_stupid_filter (stupid_filter_state_t s, u8 num_sats, sdiff_t sdiffs, double *dd_meas, double b[3], double ref_ecef[3])

Function Documentation

void amb_from_baseline	(	u8	num_sats,
		double *	DE,
		double *	dd_meas,
		double	b[3],
		s32 *	N
	)

Estimate the integer ambiguity vector from a double difference measurement and a given baseline.

Given the double difference carrier phase measurement equation:

$\Delta \nabla \phi_i = N_i + \frac{1}{\lambda} (\mathbf{e}_i - \mathbf{e}_r) \cdot \mathbf{b} + \epsilon$

where $\Delta \nabla \phi_i$ is the double differenced carrier phase between satellite $i$ and reference satellite $r$ , $N_i \in \mathbb{R}$ is the corresponding integer ambiguity, $\mathbf{e}_i$ is the unit vector to the $i$ th satellite and $\mathbf{b}$ is the baseline vector between the reover and reference station.

We can estimate $N_i$ given the baseline $\mathbf{b}$ as follows:

$\tilde{N_i} = \mathrm{round}\left(\Delta \nabla \phi_i - \frac{1}{\lambda} [\mathbf{DE} \cdot \mathbf{b}]_i + \epsilon\right)$

where the $\mathbf{DE}$ matrix is defined as:

$\mathbf{DE}_i = \mathbf{e}_i - \mathbf{e}_r$

Parameters:

num_sats	Number of satellites used
DE	Double differenced matrix of unit vectors to the satellites
dd_meas	Double differenced carrier phase measurements in cycles, length `num_sats - 1`
b	Baseline vector in meters
N	Vector where integer ambiguity estimate will be stored

Definition at line 54 of file stupid_filter.c.

void init_stupid_filter	(	stupid_filter_state_t *	s,
		u8	num_sats,
		sdiff_t *	sdiffs,
		double *	dd_meas,
		double	b[3],
		double	ref_ecef[3]
	)

Definition at line 80 of file stupid_filter.c.

u8 intersect_o_tron	(	u8	num_sats1,
		u8	num_sats2,
		u8 *	sats1,
		sdiff_t *	sdiffs,
		double *	dd_meas,
		sdiff_t *	intersection_sats,
		double *	intersection_dd_meas,
		s32 *	N,
		s32 *	intersection_N
	)

Definition at line 119 of file stupid_filter.c.

void lesq_solution	(	u8	num_dds,
		double *	dd_meas,
		s32 *	N,
		double *	DE,
		double	b[3],
		double *	resid
	)

Definition at line 175 of file stupid_filter.c.

static void rebase_N	(	s32 *	N,
		u8	num_sats,
		u8 *	old_prns,
		u8 *	new_prns
	)		`[static]`

Definition at line 92 of file stupid_filter.c.

void rebase_stupid_filter	(	stupid_filter_state_t *	s,
		u8	num_sats,
		u8 *	old_prns,
		u8 *	new_prns
	)

Definition at line 113 of file stupid_filter.c.

void update_sats_stupid_filter	(	stupid_filter_state_t *	s,
		u8	num_old,
		u8 *	old_prns,
		u8	num_new,
		sdiff_t *	sdiffs,
		double *	dd_meas,
		double	ref_ecef[3]
	)

Definition at line 141 of file stupid_filter.c.

void update_stupid_filter	(	stupid_filter_state_t *	s,
		u8	num_sats,
		sdiff_t *	sdiffs,
		double *	dd_meas,
		double	b[3],
		double	ref_ecef[3]
	)

Definition at line 229 of file stupid_filter.c.

Functions

Function Documentation