Abstract: The broadcast ephemeris parameters for GPS have the characters of less parameters, unambiguous physical significance and high precision.It may be used in hybrid-constellation satellite navigation system which includes different kinds of satellites,for example,MEO satellites, IGSO satellites and GEO satellites.The accuracy of broadcast ephemeris for above different kinds of satellite orbits using the broadcast ephemeris parameters for GPS was analyzed.The variety law of the fitting result for broadcast ephemeris parameters within an orbit period of satellite was com- pared too.The simulation result shows that the fitting errors of broadcast ephemeris for MEO, IGSO and GEO are less than decimeters.It also shows that the variety laws of the fitting result of broadcast ephemeris for MEO and IGSO satellites are similar to each other and are different to GEO satellites.

Key words: Satellite navigation system, Broadcast ephemeris parameters, hybrid-constellation