Method and apparatus for efficient acquisition and tracking of satellites

• US 6,078,286 A
• Filed: 06/03/1998
• Issued: 06/20/2000
• Est. Priority Date: 06/03/1998
• Status: Expired due to Term

• Current Assignee: CDC Propriete Intellectuelle
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Gonzales, Estevan Marcial, Bienz, Richard Alan
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): PHAN, DAO LINDA
• Application Number:
  US09/089,895
• Time in Patent Office: 748 Days
• Field of Search: 342/357.01, 342/357.06, 342/357.1, 342/357.15, 342/76, 342/359, 342/422, 342/428
• US Class Current: 342/359
• CPC Class Codes: H01Q 1/1257 using the received signal strength
• CPC Class Codes: H01Q 1/288 Satellite antennas
• CPC Class Codes: H01Q 3/08 for varying two co-ordinates of the orientation
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system

Abstract

A method and apparatus for efficiently tracking satellites includes a geosynchronous satellite (10) for transmitting the ephemeris of non-geosynchronous satellites (20, 30) to a ground terminal (50). The ephemeris is computed by the non-geosynchronous satellites (20, 30) or by other means such as a ground station (60). A ground terminal (50) can quickly acquire a non-geosynchronous satellite (20, 30) by receiving fresh ephemeris data from a geosynchronous satellite (10), determining a location of a non-geosynchronous satellite (20, 30), and orienting an antenna.

Claims

1. A method of tracking a location of a first satellite, said method comprising the steps of:

transmitting ephemeris data from said first satellite to a second satellite, wherein said ephemeris data describes said location of said first satellite;

said second satellite transmitting said ephemeris data to a ground terminal, wherein said second satellite is in a geosynchronous orbit; and

responsive to said ephemeris data, said ground terminal orienting an antenna beam such that said first satellite may be tracked.

2. The method of claim 1 further including the step of:

prior to transmitting said ephemeris data from said first satellite to said second satellite, said first satellite determining said location using Global Positioning System (GPS) signals; and

generating said ephemeris data.

3. The method of claim 1 wherein said first satellite is in a non-geosynchronous orbit.

4. A method of tracking a location of a first satellite, said method comprising the steps of:

transmitting ephemeris data from a first satellite to a second satellite, wherein said ephemeris data describes said location of said first satellite;

said second satellite transmitting said ephemeris data to a ground terminal, wherein said second satellite is in a geosynchronous orbit; and

orienting an antenna beam of said ground station in response to said ephemeris data such that said first satellite may be tracked.

5. The method of claim 4 wherein said first satellite is in a non-geosynchronous orbit.