Broadcast and utilization of precise GNSS correction data

1. A method for determining positions of a mobile system, comprising:

receiving, by a GNSS receiver of the mobile system, a first set of correction data which is broadcasted from a first transmitter, wherein the first set of correction data comprises Differential Global Navigation Satellite System (D-GNSS) correction data;

estimating, by a computer processor of the mobile system using a real-time kinematics (RTK) method, a first position of the mobile system using at least a portion of the first set of correction data;

estimating, by the computer processor using a precise point positioning (PPP) estimation method, one or more unknown parameters of the PPP estimation method based at least on the estimated first position of the mobile system and the first set of correction data;

estimating, by the computer processor, a second position of the mobile system using the estimated one or more unknown parameters and the PPP estimation method, wherein the second position of the mobile system is different from the first position of the mobile system and is obtained by fusing time and position estimates of output from the RTK method and the PPP method; and

outputting, by the computer processor, a combined position based on the first position and the second position.

2. The method of claim 1 , wherein the one or more unknown parameters comprise phase ambiguity of a carrier signal.

3. The method of claim 1 , wherein the first set of correction data is received by the first transmitter from a remote server prior to broadcast.

4. The method of claim 1 , wherein the first transmitter comprises a cellular base station.

5. The method of claim 1 , wherein the first transmitter comprises an infrastructure unit and the first set of correction data is transmitted using V2X (Vehicle to Everything) communication method.

6. The method of claim 1 , wherein the first set of correction data comprises pseudorange and phase measurements for one or more GNSS satellites, determined by the GNSS receiver, and one or more atmospheric parameters for one or more GNSS satellites.

7. The method of claim 1 , wherein accuracy of the estimated second position of the mobile system is higher than accuracy of the estimated first position of the mobile system.

8. The method of claim 1 , wherein the mobile system is a vehicle.

9. A mobile system, comprising:

a GNSS receiver configured to receive a first set of correction data, which is broadcasted from a first transmitter, wherein the first set of correction data comprises Differential Global Navigation Satellite System (D-GNSS) correction data; and

a computing system comprising:

a computer processor; and

memory storing program instructions that, when executed, cause the computer processor to:

estimate, using a real-time kinematics (RTK) method, a first position of the mobile system using at least a portion of the first set of correction data;

estimate, using a precise point positioning (PPP) estimation method, one or more unknown parameters of the PPP estimation method based at least on the estimated first position of the mobile system and the first set of correction data;

estimate a second position of the mobile system using the estimated one or more unknown parameters and the PPP estimation method, wherein the second position of the mobile system is different from the first position of the mobile system and is obtained by fusing time and position estimates of output from the RTK method and the PPP method; and

output a combined position based on the first position and the second position.

10. The mobile system of claim 9 , wherein the one or more unknown parameters comprise phase ambiguity of a carrier signal.

11. The mobile system of claim 9 , wherein the first set of correction data is aggregated by a remote server and is received by the first transmitter from the remote server prior to broadcast.

12. The mobile system of claim 9 , wherein the first transmitter is a cellular base station.

13. The mobile system of claim 9 , wherein the first transmitter is an infrastructure unit and the first set of correction data is transmitted using V2X (Vehicle to Everything) communication method.

14. The mobile system of claim 9 , wherein the first set of correction data comprises pseudorange and phase measurements for one or more GNSS satellites, determined by the GNSS receiver, and one or more atmospheric parameters for one or more GNSS satellites.

15. The mobile system of claim 9 , wherein accuracy of the estimated second position of the mobile system is higher than accuracy of the estimated first position of the mobile system.

16. The mobile system of claim 9 , wherein the mobile system is a vehicle and the GNSS receiver is mounted on the vehicle.

17. A non-transitory computer readable medium comprising program instructions that, when executed by a processor of a mobile system, perform a method for determining positions of the mobile system, comprising:

receiving, by a GNSS receiver of the mobile system, a first set of correction data which is broadcasted from a first transmitter, wherein the first set of correction data comprises Differential Global Navigation Satellite System (D-GNSS) correction data;

estimating, using a real-time kinematics (RTK) method, a first position of the mobile system using at least a portion of the first set of correction data;

estimating, using a precise point positioning (PPP) estimation method, one or more unknown parameters of the PPP estimation method based at least on the estimated first position of the mobile system and the first set of correction data;

estimating, a second position of the mobile system using the estimated one or more unknown parameters and the PPP estimation method, wherein the second position of the mobile system is different from the first position of the mobile system and is obtained by fusing time and position estimates of output from the RTK method and the PPP method; and

outputting a combined position based on the first position and the second position.

18. The non-transitory computer readable medium of claim 17 , wherein the one or more unknown parameters comprise phase ambiguity of a carrier signal.

19. The non-transitory computer readable medium of claim 17 , wherein the first set of correction data is received by the first transmitter from a remote server prior to broadcast.

20. The non-transitory computer readable medium of claim 17 , wherein the first transmitter comprises a cellular base station.