SYSTEM AND METHOD FOR AUGMENTING DGNSS WITH INTERNALLY-GENERATED DIFFERENTIAL CORRECTION

• US 20110025555A1
• Filed: 07/29/2009
• Published: 02/03/2011
• Est. Priority Date: 07/29/2009
• Status: Active Grant

• Current Assignee: Hemisphere GNSS(USA) Incorporated
• Original Assignee: Hemisphere GPS LLC (Kubota Corporation)
• Inventors: Whitehead, Michael L.
• Granted Patent: US 8,174,437 B2
• Time in Patent Office: Days
• US Class Current: 342/357.24
• CPC Class Codes: G01S 19/33 Multimode operation in different systems which transmit time stamped messages, e.g. GPS/GLONASS
• CPC Class Codes: G01S 19/41 Differential correction, e.g. DGPS [differential GPS]

Abstract

In the invention, a rover receiver first utilizes data from a base Receiver, a DGNSS reference network, or other differential source to compute a differentially corrected location. Then, using this location and data observed only at the rover, the rover computes an internal set of differential corrections that are stored in computer memory, updated as necessary, and applied in future times to correct observations taken by the rover. The possibly mobile rover receiver, therefore, corrects its own observations with differential corrections computed from its own past observations; relying on external differential for the sole purpose of establishing a reference location, and this is unlike prior art.

Claims

1. A method of computing differentially corrected global navigation satellite system (GNSS) measurements within a mobile rover receiver, which method comprises the steps of:

receiving at the rover receiver a set of differential enabling data over a communication link;

measuring at the rover receiver, at a first instant of time, a first set of satellite measurement information;

computing a differentially corrected location using said differential enabling data and said satellite measurement information;

using said location and said satellite measurement information, computing a set of differential corrections;

storing said differential corrections in computer memory;

measuring at the rover receiver, at a second instant of time, a second set of satellite measurement information; and

correcting said second set of satellite measurement information with said differential corrections.

2. The method of claim 1, which includes the additional step of receiving said differential enabling data over a communication link.

3. The method of claim 1, which includes the additional step of receiving said differential enabling data from a base receiver.

4. The method of claim 1, which includes the additional step of:

computing a second location using said second set of satellite measurement information and said differential corrections.

5. The method of claim 1, which includes the additional step of:

solving for integer ambiguities in said second set of satellite measurement information.

6. The method of claim 1 wherein GNSS satellite measurement information is received by said rover receiver from one or more of the group consisting of:

GPS;

GLONASS;

Galileo;

Compass;

a satellite-based augmentation system (SBAS);

a regional satellite system;

the wide-area augmentation system (WAAS);

a transmitter located on or near the ground; and

a pseudolite.

7. The method of claim 1 wherein said GNSS satellite measurement information contains one or more of the group consisting of:

a phase; and

a pseudorange.

8. The method of claim 1 wherein said differential enabling data contains one or more from the group consisting of:

a differential correction;

clock correctors;

orbit correctors;

a pseudorange; and

a phase.

9. The method of claim 1 wherein said communication link is to one or more of the group consisting of:

a base station;

an SBAS satellite;

an Inmarsat satellite; and

a network RTK source.