Long range GNSS ephemeris data transfer method and apparatus using the same

• US 6,336,076 B1
• Filed: 08/24/1998
• Issued: 01/01/2002
• Est. Priority Date: 08/24/1998
• Status: Expired due to Term

• Current Assignee: Rockwell Collins, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Rockwell Collins, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Corcoran, Mitchell A., Strus, Joseph M., Farley, Michael G., Schellenberg, Susan R.
• Primary Examiner(s): Nguyen, Tan
• Assistant Examiner(s): Tran, Dalena
• Application Number:
  US09/138,883
• Time in Patent Office: 1,226 Days
• Field of Search: 701/213, 701/214, 701/215, 342/357.09, 342/357.06, 342/358, 342/357.1, 342/357.12
• US Class Current: 701/213
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/11 wherein the cooperating elements are pseudolites or satellite radio beacon positioning system signal repeaters
• CPC Class Codes: G01S 19/258 relating to the satellite constellation, e.g. almanac, ephemeris data, lists of satellites in view

Abstract

Disclosed are methods of transferring satellite ephemeris data for a first GNSS satellite from a pseudolite to a GNSS receiver. Also disclosed are pseudolites and GNSS receivers implementing the same. A first satellite global positioning signal transmitted by the first GNSS satellite is received at the pseudolite. The pseudolite transmits a pseudolite global positioning signal containing the satellite ephemeris data for the first GNSS satellite. The GNSS receiver receives the pseudolite global positioning signal and retrieves from the pseudolite signal the satellite ephemeris data.

Claims

1. A method of providing satellite data for a first global navigation satellite system (GNSS) satellite to a GNSS receiver, the method comprising:

receiving at a pseudolite a first satellite global positioning signal transmitted by the first GNSS satellite, the first satellite global positioning signal containing the satellite data for the first GNSS satellite, wherein the satellite data for the first GNSS satellite includes ephemeris data for the first GNSS satellite;

generating a pseudolite global positioning signal in a global positioning system (GPS) data message format including a plurality of frames of data, wherein some of the plurality of frames describe the ephemeris data for the pseudolite, wherein others of the plurality of frames describe the ephemeris data for the first GNSS satellite, and wherein the pseudolite global positioning signal is in a modified GPS satellite block II flexible data message structure;

transmitting from the pseudolite the pseudolite global positioning signal, the pseudolite global positioning signal containing the satellite data for the first GNSS satellite;

receiving at the GNSS receiver the pseudolite global positioning signal transmitted by the pseudolite;

retrieving in the GNSS receiver the satellite data for the first GNSS satellite from the pseudolite global positioning signal; and

wherein the ephemeris data for the first GNSS satellite which is contained in the pseudolite global positioning signal allows the GNSS receiver to directly acquire a Y-code in the first satellite global positioning signal.

2. The method of claim 1, wherein the GNSS receiver is operating at a first location at which jamming signals are interfering with acquisition of a C/A code in the first satellite global positioning signal, wherein the step of receiving at the pseudolite the first satellite global positioning signal further comprises positioning the pseudolite at a second location spaced apart from the first location such that the jamming signals do not interfere with acquisition by the pseudolite of the C/A code in the first satellite global positioning signal, however, the distance separating the two locations may contain multiple pseudolite navigation links and wherein the step of transmitting from the pseudolite the pseudolite global positioning signal further comprises transmitting the pseudolite global positioning signal at a power level which allows the GNSS receiver to acquire a C/A code in the pseudolite global positioning signal while operating at the first location.

3. A pseudolite for use in a navigation system, the pseudolite comprising:

a pseudolite communications link comprised of a GNSS receiver which receives global positioning signals containing ephemeris data from at least one of a plurality of GNSS satellites and other pseudolites; and

a pseudolite transmitter coupled to the communications link and receiving the ephemeris data, the pseudolite transmitter being adapted to generate and transmit a first pseudolite global positioning signal such that the pseudolite global positioning signal is in a global positioning system (GPS) data message format including a plurality of frames of data, wherein some of the plurality of frames of data describe the ephemeris data for the pseudolite, and wherein others of the plurality of frames of data describe the ephemeris data for the at least one of the plurality of GNSS satellites and other pseudolites;

wherein a subframe identification in a handover word of the first pseudolite global positioning signal contains data which distinguishes pseudolite global positioning signals from global positioning signals from GNSS satellites.

4. The pseudolite of claim 3, wherein in the first pseudolite global positioning signal, if the subframe identification in the handover word has a value equal to one of 000, 010 and 111, then an identification of the GNSS satellite or other pseudolites whose ephemeris data is currently contained in the pseudolite global positioning signal is included in the current frame.

5. The pseudolite of claim 3, wherein the first pseudolite global positioning signal is in a modified GPS satellite block II flexible data message structure.