GNSSIR (C library)#

struct arc#

Public Members

size_t len#

size_t nreserve#

arc_state state#

gnss_system system#

int prn#

enu_position site#

double *mjd#

float *elevation#

float *azimuth#

float *values#

struct arc_buffer#

#include <arcs.h>

Stuff for the arc buffer interface.

Public Members

arc *arcbuf[ARC_BUFFER_SIZE]#

int expiry_sec#: states associated with the buffer

int max_arclen_sec#

size_t narcs#

skymask *skymaskptr#

struct enu_position#

Public Members

float lat#

float lon#

float ortho_height#

float geoid_height#

double mjd#

struct gnss_system#

Public Members

const char system[12]#

const char rinexcode[1]#

double frequency#

double length#

double bandwidth#

struct gnssrstream#

Public Members

stream_type ftype#

void *fid#

struct lz4stream#

Public Members

LZ4_readFile_t *lz4_fid#

FILE *fid#

char *mbufPtr#

char *chunkbuf#

char *chunkPtr#

size_t buflen#

struct nmea_cycle#

#include <nmea.h>

holds the information of all the GSV messages in a cycle

Public Members

double mjd#

char status#

enu_position site#

int sats_in_view#

gnss_system system[NMEA_GSV_MAX_SATELLITES]#

int prn[NMEA_GSV_MAX_SATELLITES]#

float elevation[NMEA_GSV_MAX_SATELLITES]#

float azimuth[NMEA_GSV_MAX_SATELLITES]#

float cnr0[NMEA_GSV_MAX_SATELLITES]#

struct nmea_trans_cycle#

#include <nmea.h>

Cycle structure holding a paired nmea-cycle with a transmissivity cycle.

Public Members

double mjd[2]#

enu_position sites[2]#

int sats_in_view#

gnss_system system[NMEA_GSV_MAX_SATELLITES]#

int prn[NMEA_GSV_MAX_SATELLITES]#

float elevation[NMEA_GSV_MAX_SATELLITES]#

float azimuth[NMEA_GSV_MAX_SATELLITES]#

float cnr0[2][NMEA_GSV_MAX_SATELLITES]#

float gamma[NMEA_GSV_MAX_SATELLITES]#

struct skymask#

Public Members

int npoints#

float azimuth[SKYMASK_MAX_POINTS]#

float elevation[SKYMASK_MAX_POINTS]#

az_center center#

file arcs.c

#include <memory.h>

#include “arcs.h”

#include “position.h”

Functions

int init_arc(arc *data)#

int free_arc(arc *data)#

int realloc_and_copy(void **dvec, size_t currentlen, size_t sz)#

int append_to_arc(arc *data, double mjd, float elevation, float azimuth, float value)#

int init_arc_buffer(arc_buffer *arcbuf, int expiry_sec, int max_arclen_sec)#

int free_arc_buffer(arc_buffer *arcbuf)#

arc *find_arcptr(arc_buffer *arcbuf, int prn)#

int new_arc(arc **arcptr, arc_buffer *arcbuf, int prn, const gnss_system *sys, const enu_position *site)#

int check_finalization(arc_buffer *arcbuf, double mjdcurrent)#

int append_cycle_data(const nmea_cycle *cyc, arc_buffer *arcbuf)#

int next_finalized_arc(const arc_buffer *abuf)#

int insert_new_arc(arc_buffer *abuf, int itharc)#

int purge_arc(arc_buffer *abuf, int itharc)#

file arcs.h

#include “gnssir.h”

#include “nmea.h”

#include “skymask.h”

Defines

ARC_DATA_CHUNK#

ARC_FILL_VALUE#

ARC_BUFFER_SIZE#

ARC_FULL_BUFFER#

Typedefs

typedef enum arc_state arc_state

typedef struct arc arc

typedef struct arc_buffer arc_buffer

Enums

enum arc_state#

Values:

enumerator FINAL#

enumerator OPEN#

Functions

int init_arc(arc *data)

int free_arc(arc *data)

int append_to_arc(arc *data, double mjd, float elevation, float azimuth, float cnr0)

int init_arc_buffer(arc_buffer *arcbuf, int expiry_sec, int max_arclen_sec)

int free_arc_buffer(arc_buffer *arcbuf)

int append_cycle_data(const nmea_cycle *cyc, arc_buffer *arcbuf)

int next_finalized_arc(const arc_buffer *abuf)

int purge_arc(arc_buffer *abuf, int itharc)

int insert_new_arc(arc_buffer *abuf, int itharc)

file gnssir.c

#include “gnssir.h”

#include <string.h>

Variables

const gnss_system gnss_unknown = GNSS_UNKNOWN#

const gnss_system gnss_gpsl1 = GPSL1#

const gnss_system gnss_gpsl2 = GPSL2#

file gnssir.h

#include <stdio.h>

#include <stdlib.h>

Defines

GNSSIR_SUCCESS#: ERROR and SUCCESS CODES.

GNSSIR_MEMORY_ERROR#

ALLOC(s)#

ALLOC_AND_ZERO(s)#

FREEMEM(p)#

F_FILL_VALUE#

SPEED_OF_LIGHT#

GNSS_BAND(FREQ, WMHZ, NAME, RINEXCODE)#

GPSL1#

GPSL2#

GPSL5#

QZSSL5#

QZSSL2C#

QZSSE6#

QZSSL1#

GLONASSIL1#

GLONASSIL2#

GLONASSIIL1#

GLONASSIIL2#

GNSS_UNKNOWN#

LOGWARNING#

warn_print(fmt, ...)#

Typedefs

typedef struct gnss_system gnss_system

Functions

void copy_GNSS_as(gnss_system *sys, const gnss_system *sysfrom)#

Variables

const gnss_system gnss_gpsl1

const gnss_system gnss_gpsl2

const gnss_system gnss_glonassiil1#

const gnss_system gnss_unknown

file lz4stream.c

#include “lz4stream.h”

#include <stdlib.h>

#include <string.h>

Functions

lz4stream *open_lz4stream(const char *filename)#

int decompress_lz4_chunk(lz4stream *lzid)#

int readline_lz4(lz4stream *lzid, char *buffer, size_t slen)#

void close_lz4stream(lz4stream *lzid)#

file lz4stream.h

#include “lz4static/lz4.h”

#include “lz4static/lz4file.h”

#include <stdio.h>

Defines

LZ4_MAX_MESSAGE#

LZ4_RING_BUFFER#

LZ4_CHUNK_SIZE#

LZ4_ERROR#

LZ4_EOF#

LZ4_SUCCESS#

LZ4_LINEBUF_TOO_SMALL#

Typedefs

typedef struct lz4stream lz4stream

Functions

lz4stream *open_lz4stream(const char *filename)

void close_lz4stream(lz4stream *lzid)

int readline_lz4(lz4stream *lzid, char *buffer, size_t slen)

int decompress_lz4_chunk(lz4stream *lzid)

file nmea.c

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <math.h>

#include “nmea.h”

#include “timeutil.h”

Functions

unsigned char calculate_checksum(const char *nmea)#

int shift_to_komma(const char **nmeaPtr, const char **kommaPtr, int skip)#

float convert_deg(const float deg)#

void extract_time(const char *nmeaPtr, int *hr, int *min, double *sec)#

int init_nmea_cycle(nmea_cycle *data)#

int init_nmea_trans_cycle(nmea_trans_cycle *data)#

nmea_type check_nmea(char *nmea)#

int read_nmea_cycle(gnssrstream *sid, nmea_cycle *data)#

int pair_nmea_trans_cycle(const nmea_cycle *c_obstr, const nmea_cycle *c_clear, int delta_sec, nmea_trans_cycle *tc_out)#: Create a transmissivity cycle from two individual cycles (no checks on matching time will be done!! (this is a user choice)

int update_nmea_RMC(const char *nmea, nmea_cycle *data)#

void get_gnss_system(const char *nmea, gnss_system *system)#

int update_nmea_GSV(const char *nmea, nmea_cycle *data)#

int update_nmea_GGA(const char *nmea, nmea_cycle *data)#

file nmea.h

#include <stdio.h>

#include <zlib.h>

#include <string.h>

#include “gnssir.h”

#include “stream.h”

#include “position.h”

Defines

NMEA_BUFFER_SIZE#

NMEA_GSV_MAX_SATELLITES#

NMEA_FILL#

Typedefs

typedef enum nmea_type nmea_type

typedef struct nmea_trans_cycle nmea_trans_cycle

typedef struct nmea_cycle nmea_cycle

Enums

enum nmea_type#

Values:

enumerator NMEA_GGA#

enumerator NMEA_GSV#

enumerator NMEA_GLL#

enumerator NMEA_GSA#

enumerator NMEA_RMC#

enumerator NMEA_VTG#

enumerator NMEA_GNS#

enumerator NMEA_UNSUPPORTED#

enumerator NMEA_INVALID#

Functions

unsigned char calculate_checksum(const char *nmea)

int update_nmea_RMC(const char *nmea, nmea_cycle *data)

int update_nmea_GSV(const char *nmea, nmea_cycle *data)

int update_nmea_GGA(const char *nmea, nmea_cycle *data)

nmea_type check_nmea(char *nmea)

int init_nmea_cycle(nmea_cycle *data)

int init_nmea_trans_cycle(nmea_trans_cycle *data)

int read_nmea_cycle(gnssrstream *sid, nmea_cycle *data)

int pair_nmea_trans_cycle(const nmea_cycle *c_clear, const nmea_cycle *c_obstr, int delta_sec, nmea_trans_cycle *tc_out): Create a transmissivity cycle from two individual cycles (no checks on matching time will be done!! (this is a user choice)

file position.c

#include “gnssir.h”

#include “position.h”

Functions

int init_enu_position(enu_position *data)#

int copy_enu_position(const enu_position *in, enu_position *out)#

int set_enu_position(enu_position *data, float lat, float lon, float ortho_height, float geoid_height, double mjd)#

file position.h

Typedefs

typedef struct enu_position enu_position

Functions

int init_enu_position(enu_position *data)

int copy_enu_position(const enu_position *in, enu_position *out)

int set_enu_position(enu_position *data, float lat, float lon, float ortho_height, float geoid_height, double mjd)

file skymask.c

#include “skymask.h”

Functions

int within_mask(const skymask *skymsk, float azimuth, float elevation)#

Tests whether a point (azimuth, elevation) lies within a skymask polygon.

Uses a fast point-in-polygon test algorithm based on ray casting to determine if a given sky coordinate falls within the polygon defined by the skymask vertices.

See also

skymask

See also

az_center

Note

The azimuth value is automatically wrapped to match the skymask’s coordinate system center

Note

Algorithm adapted from: https://stackoverflow.com/questions/36399381/whats-the-fastest-way-of-checking-if-a-point-is-inside-a-polygon-in-python

Parameters:

skymsk – Pointer to the skymask structure containing polygon vertices
azimuth – The azimuth angle in degrees of the point to test
elevation – The elevation angle in degrees of the point to test

Returns:

1 if the point is inside the polygon, 0 if outside, 2 if on the edge

int init_skymask(skymask *skymsk)#

int add_polypoint(skymask *skymsk, float azimuth, float elevation)#

int close_poly(skymask *skymsk)#

int setup_simple_skymask(skymask *skymsk, float min_az, float max_az, float min_el, float max_el)#

float wrap_azimuth(float azimuth, az_center center)#

Wraps azimuth angle to match the specified azimuth center (0 or 180 degrees).

Converts azimuth angles between two coordinate systems:

D180 center: Range [0, 360) degrees
D0 center: Range [-180, 180) degrees

Note

If azimuth is negative and center is D180, adds 360 to convert to [0,360) range

Note

If azimuth is greater than 180 and center is D0, subtracts 360 to convert to [-180,180) range

Note

If no conversion is needed, returns the original azimuth value

Parameters:

azimuth – The azimuth angle in degrees to be wrapped
center – The target coordinate system center (see az_center enum in skymask.h)

Returns:

The wrapped azimuth angle in the target coordinate system

file skymask.h

#include “gnssir.h”

Defines

SKYMASK_MAX_POINTS#

SKYMASK_FULL#

SKYMASK_INVALID#

Typedefs

typedef enum az_center az_center

typedef struct skymask skymask

Enums

enum az_center#

Defines the azimuthal center point for a skymask polygon.

This enumeration specifies different coordinate system conventions for representing azimuth angles, determining whether angles are centered around 0° or 180°.

Values:

enumerator D0#: Center at 0°: Azimuth range is [-180°, 180°)

enumerator D180#: Center at 180°: Azimuth range is [0°, 360°)

enumerator DUNK#: Unknown or unspecified center (value: 1)

Functions

int init_skymask(skymask *skymsk)

int within_mask(const skymask *skymsk, float azimuth, float elevation)

Tests whether a point (azimuth, elevation) lies within a skymask polygon.

Uses a fast point-in-polygon test algorithm based on ray casting to determine if a given sky coordinate falls within the polygon defined by the skymask vertices.

See also

skymask

See also

az_center

Note

The azimuth value is automatically wrapped to match the skymask’s coordinate system center

Note

Algorithm adapted from: https://stackoverflow.com/questions/36399381/whats-the-fastest-way-of-checking-if-a-point-is-inside-a-polygon-in-python

Parameters:

skymsk – Pointer to the skymask structure containing polygon vertices
azimuth – The azimuth angle in degrees of the point to test
elevation – The elevation angle in degrees of the point to test

Returns:

1 if the point is inside the polygon, 0 if outside, 2 if on the edge

int add_polypoint(skymask *skymsk, float azimuth, float elevation)

int close_poly(skymask *skymsk)

int setup_simple_skymask(skymask *skymsk, float min_az, float max_az, float min_el, float max_el)

float wrap_azimuth(float azimuth, az_center center)

Wraps azimuth angle to match the specified azimuth center (0 or 180 degrees).

Converts azimuth angles between two coordinate systems:

D180 center: Range [0, 360) degrees
D0 center: Range [-180, 180) degrees

Note

If azimuth is negative and center is D180, adds 360 to convert to [0,360) range

Note

If azimuth is greater than 180 and center is D0, subtracts 360 to convert to [-180,180) range

Note

If no conversion is needed, returns the original azimuth value

Parameters:

azimuth – The azimuth angle in degrees to be wrapped
center – The target coordinate system center (see az_center enum in skymask.h)

Returns:

The wrapped azimuth angle in the target coordinate system

file stream.c

#include <stdio.h>

#include <string.h>

#include “gnssir.h”

#include “stream.h”

Functions

int open_stream(const char *filename, gnssrstream *sid)#

void close_stream(gnssrstream *sid)#

int readline(gnssrstream *sid, char *buffer, size_t slen)#

file stream.h

#include <string.h>

#include <stdio.h>

Defines

GNSSR_IO_ERROR#

GNSSR_EOF#

GNSSR_SUCCESS#

GNSSR_NOMATCH#

Typedefs

typedef struct gnssrstream gnssrstream

Enums

enum stream_type#

Values:

enumerator UNCOMPRESSED#

Functions

int open_stream(const char *filename, gnssrstream *strid)

int readline(gnssrstream *strid, char *buffer, size_t slen)

void close_stream(gnssrstream *strid)

int eof(gnssrstream *strid)#

file timeutil.c

Functions

double mjd(const int year, const int month, const int day, const int hour, const int minute, const double second)#

void mjd_to_datetime(double mjd, int *year, int *month, int *day, int *hour, int *minute, double *second)#

file timeutil.h

Functions

double mjd(const int year, const int month, const int day, const int hour, const int minute, const double seccond)

void mjd_to_datetime(double mjd, int *year, int *month, int *day, int *hour, int *minute, double *second)

dir /home/docs/checkouts/readthedocs.org/user_builds/gnssr4water/envs/latest/lib/python3.12/site-packages/gnssir/src

GNSSIR (C library)#

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