Table 1.

Selected ephemeris parameter of GPS L1 signal.

Ephemeris Data	Definition	No. of Bits	Scale Factor (LSB)	Units
M0	Mean anomaly at reference time	32	2−31	Semi-circles
Δn	Mean motion difference from computed value	16	2−43	Semi-circles/sec
e	Eccentricity	32	2−33	Dimensionless
A1/2	Square root of the semi-major axis	32	2−19	Meters1/2
Ω0	Longitude of ascending node of orbit plane at weekly epoch	32	2−31	Semi-circles
i0	Inclination angle at reference time	32	2−31	Semi-circles
ω	Argument of perigee	32	2−31	Semi-circles
Ω̇	Rate of right ascension	24	2−43	Semi-circles/sec
i̇	Rate of inclination angle	14	2−43	Semi-circles/sec