Position locating and communication system using multiple satellite constellations

• US 5,619,211 A
• Filed: 11/17/1994
• Issued: 04/08/1997
• Est. Priority Date: 11/17/1994
• Status: Expired due to Term

• Current Assignee: CDC Propriete Intellectuelle
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Horkin, Philip R., Ma, Stephen C., Durboraw, III, Isaac N., Muncaster, George W.
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US08/341,244
• Time in Patent Office: 873 Days
• Field of Search: 342/356, 342/357, 342/352, 244/158 R, 244/159
• US Class Current: 342/357.21
• CPC Class Codes: H04B 7/18508 with satellite system used as relay, i.e. aeronautical mobile satellite service
• CPC Class Codes: H04B 7/1855 using a telephonic control signal, e.g. propagation delay variation, Doppler frequency variation, power variation, beam identification
• CPC Class Codes: H04B 7/18554 using the position provided by an existing geolocalisation system

Abstract

A communication and position locating system (2) suitable for air traffic control is described. Multiple satellites (40) are provided in two geosynchronous constellations. One constellation (e.g., 4 satellites) has a first closed ground track (14). The other (e.g., 2 satellites (161, 182)) has a different ground track (18) or is geostationary, located outside of the first ground track (14). Geolocation information is transmitted by the satellites (40) to aircraft (28) and ground stations (26) so that aircraft (28) can determine their current position. A pseudo range correction map is provided to the aircraft (28) by the base stations (26) to permit differential geolocation measurements. The satellites (40) include communication transceivers (80) so that aircraft (28) can communicate voice and data to other aircraft (28) and to the ground stations (26, 30, 32) and automatically report their position to air traffic control centers (30), e.g., via the satellites (40). High positional accuracy over large geographic areas is obtained.

Claims

1. A system for providing location information to users, comprising:

a first group of at least three geolocation information transmitting satellites in substantially geosynchronous independent elliptical first orbits around the Earth, wherein said first orbits are inclined to earth'"'"'s equatorial plane by at least ten degrees and with orbital parameters providing first closed ground tracks having longitudinal extent greater than zero and less than one hundred and eighty degrees, and each of said first closed ground tracks of said satellites of said first group being substantially common, and said first closed ground tracks defining a predetermined area of coverage wherein said user is located; and

a second group of one or more geolocation transmitting satellites in substantially geosynchronous second orbits around the earth, wherein said second orbits provide ground tracks lying substantially outside the first ground tracks and wherein said user obtains non-indeterminate positional fixes from said first group of at least three geolocation information transmitting satellites and from said second group of one or more geolocation transmitting satellites.

2. A system for providing location information to users, comprising, at least six substantially geosynchronous satellites in at least two constellations having different ground tracks, wherein a first constellation comprises a grouping of three or more satellites having independent elliptical orbits with substantially common first closed ground tracks, said first closed ground tracks defining a predetermined area of coverage wherein said user is located and a second constellation comprises a second grouping of one or more satellites with second closed ground tracks, wherein said second ground tracks lie outside said first ground tracks and wherein said satellites transmit location information permitting said users to determine their position when at least four of said satellites are in view.

3. A system for providing location information to users, comprising at least six substantially geosynchronous orbiting satellites transmitting said location information having at least first closed ground tracks and second ground tracks, wherein a first portion of said at least six substantially geosynchronous orbiting satellites having said at least first closed ground tracks have independent elliptical orbits, said first closed ground tracks having longitudinal extent of about 30-180 degrees, and said first closed ground tracks being substantially common and defining a predetermined area of coverage wherein said user is located, said user obtains non-indeterminate positional fixes from said at least six substantially geosynchronous orbiting satellites.

4. The system of claim 3 wherein the longitudinal extent is about 40-100 degrees.

5. The system of claim 3 wherein the longitudinal extent is about 50-70 degrees.

6. The system of claim 3 further comprising communication transceivers in at least two of the satellites, said communication transceivers having a ground footprint which includes at least the first closed ground track.

7. The system of claim 4 further comprising communication transceivers in at least two of the satellites, said communication transceivers having a ground footprint which includes at least the first closed ground tracks and the second ground tracks.

8. The system of claim 3 wherein an angle of inclination of orbits of satellites describing the first closed ground tracks are in a range of 10-70 degrees.

9. The system of claim 8 wherein the angle of inclination of orbits of satellites describing the first closed ground tracks are in a range of 20-40 degrees.

10. The system of claim 9 wherein the angle of inclination of orbits of satellites describing the first closed ground tracks are in a range of 25-35 degrees.

11. The system of claim 3 further comprising communication transceivers for voice and data reception and transmission to and from remotely located users and destinations.