LinksPoint GPS Toolkit Reference
SIRF_EPHEMERIS_DATA
Types | See Also
Format of ephemeris data from a SiRF receiver
See Also
Members
Members Description
double dEphaf0; Clock phase offset coefficient units: sec, range: -9.766e-04 to +9.766e-04
double dEphm0; Mean anomaly at reference time of week units: radians, range: -pi to +pi
double dEphe; Eccentricity of the satellite's orbit units: n/a, range: 0 to 0.03
double dEphsqa; Square root of the transmitter's (sv) semi-major orbital axis. Assuming orbit is elliptical. this parameter is used to determine if the transmitter is ground-based. units: meters ** 0.5, range: 0 to 8192
double dEphom0; (OMEGA)o - right ascension at reference time. units: radians, range: -pi to pi
double dEphi0; Io - Inclination angle at reference time. units: radians, range: -pi to +pi
double dEphw; w - argument of perigee. units: radians, range: -pi to +pi
double dEphomd; OMEGADOT - rate of right ascension. units: radians/second, -pi e-07 to +pi e-07
double dEphtgd; Group delay time. accounts for time between the generation of the transmitter clock and its actual broadcast. units: seconds, range: -5.96e+08 to +5.96e+08
double dEphaf2; Clock frequency drift coefficient. equal to 0 if almanac data. units: sec/sec*sec, -3.5e-15 to +3.5e-15
double dEphaf1; Clock frequency offset coefficient. units: sec/sec, range: -3.72e-09 to +3.72e-09
double dEphcrs; Crs - amplitude of the sine harmonic correction term to the orbit radius. units: meters, range: -1024e-4 to +1024
double dEphmdn; Mean motion difference from computed value. equal to 0 if almanac data. units: radians/seconds,-11.6e-09 to +11.6e-09
double dEphcuc; Crc - amplitude of the cosine harmonic correctio* term to the argument of latitude. equal to 0 if almanac data. units: radians, range: -6.1e-05 to +6.1e+05
double dEphcus; Cus - amplitude of the sine harmonic correction term to the argument of latitude. equal to zero if almanac data. units: radians, range: -6.1e-05 to +6.1e-05
double dEphcic; Cic - amplitude of the cosine harmonic correc- tion term to the angle of inclination. equal to 0 if almanac data. units: radians, range: -6.1e-05 to +6.1e-05
double dEphcis; Cis - amplitude of the sine harmonic correction term to the angle of inclination. equal to 0 if almanac data. units: radians, range: -6.1e-05 to +6.1e-05
double dEphcrc; Crc - amplitude of the cosine harmonic correc- tion term to the orbit radius. equal to 0 if almanac data. units: meters, range: -1024 to +1024
double dEphidt; IDOT - rate of change of inclination angle. equal to 0 if almanac data. units: radians/second, -29.3e-10 to +29.3e-10
long int lEphadc; Data set indicator number of ephemeris parameter which vary from curve fit to curve fit. equal to 0 if almanac data. units: seconds, range: 1 to 524288 this is hte same as AODE !!!
long int lEphtoc; The clock correction parameters af0,af1 and af2 define a curve used to correct the time sent from the satellite. the clock time is the reference point for which the curve is valid. units: seconds, range: 0 to 604800
long int lEphtoe; Toe - gps time of week referenced from the start of the week. the middle of the fit interval from which calculations are based,for ephemeris data, this time is 2 or 3 hours after the start of the interval, depending on the length of the interval. if almanac data, this time is 3.5 days after the start of the week. units: seconds, range: 0 to 604800
short int sEphfit; Duration of the interval over which the satellite's ephemeris fit (a segment of its orbital path) has been forecast. 0 = 4 hour segment forecast 1 = 6 hour segment forecast units: n/a, range: o or 1
short int sEphwno; Gps week number broadcast by the transmitter or forecast by the almanac. units: weeks, range: 0 to 1023
short int sEphacc; User range accuracy. units: n/a, range: 0 to 15
short int sHealth; 0 = sv signals ok 1 = c/a only 2 = l1 only 4 = sv useless
long int lEphaodc; Age of data clock - not required ??
double dEphdeltan; Almanac parameter - not required
Group
Declaration
typedef struct {
  double dEphaf0;
  double dEphm0;
  double dEphe;
  double dEphsqa;
  double dEphom0;
  double dEphi0;
  double dEphw;
  double dEphomd;
  double dEphtgd;
  double dEphaf2;
  double dEphaf1;
  double dEphcrs;
  double dEphmdn;
  double dEphcuc;
  double dEphcus;
  double dEphcic;
  double dEphcis;
  double dEphcrc;
  double dEphidt;
  long int lEphadc;
  long int lEphtoc;
  long int lEphtoe;
  short int sEphfit;
  short int sEphwno;
  short int sEphacc;
  short int sHealth;
  long int lEphaodc;
  double dEphdeltan;
} SIRF_EPHEMERIS_DATA;
File
sirfapi.h
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