Classes | Functions
Almanac

Classes

struct  almanac_t

Functions

void calc_sat_az_el_almanac (almanac_t *alm, double t, s16 week, double ref[3], double *az, double *el)
double calc_sat_doppler_almanac (almanac_t *alm, double t, s16 week, double ref[3])
void calc_sat_state_almanac (almanac_t *alm, double t, s16 week, double pos[3], double vel[3])

Detailed Description

Functions and calculations related to the GPS almanac.

Note:
All positions are referenced to the WGS84 coordinate system.
See also:
Coordinate systems

Function Documentation

void calc_sat_az_el_almanac ( almanac_t alm,
double  t,
s16  week,
double  ref[3],
double *  az,
double *  el 
)

Calculate the azimuth and elevation of a satellite from a reference position given the satellite almanac.

Parameters:
almPointer to an almanac structure for the satellite of interest.
tGPS time of week at which to calculate the az/el.
weekGPS week number modulo 1024 or pass -1 to assume within one half-week of the almanac time of applicability.
refECEF coordinates of the reference point from which the azimuth and elevation is to be determined, passed as [X, Y, Z], all in meters.
azPointer to where to store the calculated azimuth output.
elPointer to where to store the calculated elevation output.

Definition at line 130 of file almanac.c.

double calc_sat_doppler_almanac ( almanac_t alm,
double  t,
s16  week,
double  ref[3] 
)

Calculate the Doppler shift of a satellite as observed at a reference position given the satellite almanac.

Parameters:
almPointer to an almanac structure for the satellite of interest.
tGPS time of week at which to calculate the Doppler shift.
weekGPS week number modulo 1024 or pass -1 to assume within one half-week of the almanac time of applicability.
refECEF coordinates of the reference point from which the azimuth and elevation is to be determined, passed as [X, Y, Z], all in meters.
Returns:
The Doppler shift in Hz.

Definition at line 150 of file almanac.c.

void calc_sat_state_almanac ( almanac_t alm,
double  t,
s16  week,
double  pos[3],
double  vel[3] 
)

Calculate the position / velocity state of a satellite from the almanac.

Parameters:
almPointer to an almanac structure for the satellite of interest.
tGPS time of week at which to calculate the satellite state in seconds since Sunday.
weekGPS week number modulo 1024 or pass -1 to assume within one half-week of the almanac time of applicability.
posThe satellite position in ECEF coordinates is returned in this vector.
velThe satellite velocity in ECEF coordinates is returned in this vector. Ignored if NULL.

Definition at line 39 of file almanac.c.



enu
Author(s): Mike Purvis
autogenerated on Fri Jan 3 2014 11:21:07