GPS_structEphemeris Struct Reference

#include <gps.h>


Detailed Description

A set of satellite orbit parameters that is used to calculate GPS satellite positions and velocities. In the ephemeris structure below, the parameters for computing satellite clock corrections are also included.

Author:
Glenn D. MacGougan (GDM)
Date:
2005-08-14
Since:
2005-08-14
Remarks:
(1) struct packaging: compatible with 4 and 8 byte packing
REFERENCES
[1] ICD-GPS-200C, p. 93-102

Definition at line 62 of file gps.h.


Data Fields

unsigned toe
 reference time ephemeris (0-604800) [s]
unsigned toc
 reference time (clock) (0-604800) [s]
unsigned short prn
 GPS PRN number.
unsigned short week
 10 bit gps week 0-1023 (user must account for week rollover ) [week]
unsigned short iodc
 10 bit issue of data (clock) []
unsigned short reserved1
 reserved bytes
unsigned char iode
 8 bit issue of data (ephemeris) []
unsigned char health
 6 bit health parameter, 0 if healthy, unhealth othersize [0=healthy]
unsigned char alert_flag
 1 = URA may be worse than indicated [0,1]
unsigned char anti_spoof
 anti-spoof flag from 0=off, 1=on [0,1]
unsigned char code_on_L2
 0=reserved, 1=P code on L2, 2=C/A on L2 [0,1,2]
unsigned char L2_P_data_flag
 flag indicating if P is on L2 1=true [0,1]
unsigned char fit_interval_flag
 fit interval flag (four hour interval or longer) 0=4 fours, 1=greater [0,1]
unsigned char ura
 User Range Accuracy lookup code, 0 is excellent, 15 is use at own risk [0-15], see p. 83 GPSICD200C.
unsigned short age_of_data_offset
 age of data offset [s]
unsigned short tow_week
 The week corresponding to tow (0-1024+). Can be one week larger than week. [week].
unsigned tow
 The time of week derived formt the Z-count in the Hand Over Word (HOW) [s].
double tgd
 group delay [s]
double af2
 polynomial clock correction coefficient (rate of clock drift) [s/s^2]
double af1
 polynomial clock correction coefficient (clock drift) [s/s] Note: parameters from ephemeris preferred vs almanac (16 vs 11 bits)
double af0
 polynomial clock correction coefficient (clock bias) [s] Note: parameters from ephemeris preferred vs almanac (22 vs 11 bits)
double m0
 mean anomaly at reference time [rad]
double delta_n
 mean motion difference from computed value [rad/s]
double ecc
 eccentricity []
double sqrta
 square root of the semi-major axis [m^(1/2)]
double omega0
 longitude of ascending node of orbit plane at weekly epoch [rad]
double i0
 inclination angle at reference time [rad]
double w
 argument of perigee [rad]
double omegadot
 rate of right ascension [rad/s]
double idot
 rate of inclination angle [rad/s]
double cuc
 amplitude of the cosine harmonic correction term to the argument of latitude [rad]
double cus
 amplitude of the sine harmonic correction term to the argument of latitude [rad]
double crc
 amplitude of the cosine harmonic correction term to the orbit radius [m]
double crs
 amplitude of the sine harmonic correction term to the orbit radius [m]
double cic
 amplitude of the cosine harmonic correction term to the angle of inclination [rad]
double cis
 amplitude of the sine harmonic correction term to the angle of inclination [rad]

Field Documentation

unsigned GPS_structEphemeris::toe

reference time ephemeris (0-604800) [s]

Definition at line 64 of file gps.h.

unsigned GPS_structEphemeris::toc

reference time (clock) (0-604800) [s]

Definition at line 65 of file gps.h.

unsigned short GPS_structEphemeris::prn

GPS PRN number.

Definition at line 67 of file gps.h.

unsigned short GPS_structEphemeris::week

10 bit gps week 0-1023 (user must account for week rollover ) [week]

Definition at line 68 of file gps.h.

unsigned short GPS_structEphemeris::iodc

10 bit issue of data (clock) []

Definition at line 69 of file gps.h.

unsigned short GPS_structEphemeris::reserved1

reserved bytes

Definition at line 70 of file gps.h.

unsigned char GPS_structEphemeris::iode

8 bit issue of data (ephemeris) []

Definition at line 72 of file gps.h.

unsigned char GPS_structEphemeris::health

6 bit health parameter, 0 if healthy, unhealth othersize [0=healthy]

Definition at line 73 of file gps.h.

unsigned char GPS_structEphemeris::alert_flag

1 = URA may be worse than indicated [0,1]

Definition at line 74 of file gps.h.

unsigned char GPS_structEphemeris::anti_spoof

anti-spoof flag from 0=off, 1=on [0,1]

Definition at line 75 of file gps.h.

unsigned char GPS_structEphemeris::code_on_L2

0=reserved, 1=P code on L2, 2=C/A on L2 [0,1,2]

Definition at line 76 of file gps.h.

unsigned char GPS_structEphemeris::L2_P_data_flag

flag indicating if P is on L2 1=true [0,1]

Definition at line 77 of file gps.h.

unsigned char GPS_structEphemeris::fit_interval_flag

fit interval flag (four hour interval or longer) 0=4 fours, 1=greater [0,1]

Definition at line 78 of file gps.h.

unsigned char GPS_structEphemeris::ura

User Range Accuracy lookup code, 0 is excellent, 15 is use at own risk [0-15], see p. 83 GPSICD200C.

Definition at line 79 of file gps.h.

unsigned short GPS_structEphemeris::age_of_data_offset

age of data offset [s]

Definition at line 80 of file gps.h.

unsigned short GPS_structEphemeris::tow_week

The week corresponding to tow (0-1024+). Can be one week larger than week. [week].

Definition at line 81 of file gps.h.

unsigned GPS_structEphemeris::tow

The time of week derived formt the Z-count in the Hand Over Word (HOW) [s].

Definition at line 82 of file gps.h.

double GPS_structEphemeris::tgd

group delay [s]

Definition at line 85 of file gps.h.

double GPS_structEphemeris::af2

polynomial clock correction coefficient (rate of clock drift) [s/s^2]

Definition at line 86 of file gps.h.

double GPS_structEphemeris::af1

polynomial clock correction coefficient (clock drift) [s/s] Note: parameters from ephemeris preferred vs almanac (16 vs 11 bits)

Definition at line 87 of file gps.h.

double GPS_structEphemeris::af0

polynomial clock correction coefficient (clock bias) [s] Note: parameters from ephemeris preferred vs almanac (22 vs 11 bits)

Definition at line 88 of file gps.h.

double GPS_structEphemeris::m0

mean anomaly at reference time [rad]

Definition at line 91 of file gps.h.

double GPS_structEphemeris::delta_n

mean motion difference from computed value [rad/s]

Definition at line 92 of file gps.h.

double GPS_structEphemeris::ecc

eccentricity []

Definition at line 93 of file gps.h.

double GPS_structEphemeris::sqrta

square root of the semi-major axis [m^(1/2)]

Definition at line 94 of file gps.h.

double GPS_structEphemeris::omega0

longitude of ascending node of orbit plane at weekly epoch [rad]

Definition at line 95 of file gps.h.

double GPS_structEphemeris::i0

inclination angle at reference time [rad]

Definition at line 96 of file gps.h.

double GPS_structEphemeris::w

argument of perigee [rad]

Definition at line 97 of file gps.h.

double GPS_structEphemeris::omegadot

rate of right ascension [rad/s]

Definition at line 98 of file gps.h.

double GPS_structEphemeris::idot

rate of inclination angle [rad/s]

Definition at line 99 of file gps.h.

double GPS_structEphemeris::cuc

amplitude of the cosine harmonic correction term to the argument of latitude [rad]

Definition at line 100 of file gps.h.

double GPS_structEphemeris::cus

amplitude of the sine harmonic correction term to the argument of latitude [rad]

Definition at line 101 of file gps.h.

double GPS_structEphemeris::crc

amplitude of the cosine harmonic correction term to the orbit radius [m]

Definition at line 102 of file gps.h.

double GPS_structEphemeris::crs

amplitude of the sine harmonic correction term to the orbit radius [m]

Definition at line 103 of file gps.h.

double GPS_structEphemeris::cic

amplitude of the cosine harmonic correction term to the angle of inclination [rad]

Definition at line 104 of file gps.h.

double GPS_structEphemeris::cis

amplitude of the sine harmonic correction term to the angle of inclination [rad]

Definition at line 105 of file gps.h.


The documentation for this struct was generated from the following file: