Calculating a position of one device relative to another

1 . A method of calculating a position of a first device relative to a reference device, each of the devices comprising a Global Navigation Satellite System (GNSS) receiver, the method comprising:

obtaining, from the reference device, first reference GNSS measurements, made at the reference device, for a first time;

obtaining, from the reference device, a position of the reference device, for the first time;

receiving, at a GNSS receiver of the first device, GNSS signals from at least one GNSS satellite;

obtaining first device GNSS measurements based on the GNSS signals, made at the first device, for a current time;

calculating a first relative position of the first device, for the current time, relative to the position of the reference device, for the first time, based on the first device GNSS measurements;

obtaining, from the reference device, second reference GNSS measurements, made at the reference device, for a second time, wherein the second time is subsequent to the first time;

calculating a position change of the reference device, from the first time to the second time, by comparing the first reference GNSS measurements and the second reference GNSS measurements; and

calculating a second relative position of the first device, for the current time, relative to the position of the reference device, for the second time, by combining the first relative position and the calculated position change of the reference device, wherein calculating the first relative position begins before obtaining second reference GNSS measurements, thereby reducing a latency in calculating the second relative position of the first device.

2 . The method of claim 1 , wherein the first device GNSS measurements comprise at least carrier range measurements.

3 . The method of claim 1 , wherein the first reference GNSS measurements comprise pseudorange measurements and carrier range measurements.

4 . The method of claim 1 , wherein the second reference GNSS measurements comprise at least carrier range measurements.

5 . The method of claim 1 , wherein calculating the first relative position of the first device comprises calculating a carrier phase differential solution.

6 . The method of claim 1 wherein calculating the position change of the reference device comprises calculating a delta carrier range solution.

7 . The method of claim 1 , performed entirely at the first device.

8 . The method of claim 1 wherein calculating the second relative position occurs before or without obtaining, from the reference device, a position of the reference device at the second time.

9 . One or more tangible, non-transitory, computer-readable media storing instructions that, when executed by one or more machines, cause the one or more machines to perform operations comprising:

obtaining, from a reference device, first reference Global Navigation Satellite System (GNSS) measurements, made at the reference device, for a first time, wherein the reference device comprises a GNSS receiver;

obtaining, from the reference device, a position of the reference device, for the first time;

receiving, at a GNSS receiver of a first device, GNSS signals from at least one GNSS satellite;

obtaining first device GNSS measurements based on the GNSS signals, made at a first device, for a current time, wherein the first device comprises a GNSS receiver;

calculating a first relative position of the first device, for the current time, relative to the position of the reference device, for the first time, based on the first device GNSS measurements;

obtaining, from the reference device, second reference GNSS measurements, made at the reference device, for a second time, wherein the second time is subsequent to the first time;

calculating a position change of the reference device, from the first time to the second time, by comparing the first reference GNSS measurements and the second reference GNSS measurements; and

calculating a second relative position of the first device, for the current time, relative to the position of the reference device, for the second time, by combining the first relative position and the calculated position change of the reference device, wherein calculating the second relative position begins before obtaining second reference GNSS measurements, thereby reducing a latency in calculating the second relative position of the first device.

10 . The one or more tangible, non-transitory, computer-readable media of claim 9 , wherein calculating the second relative position occurs before or without obtaining, from the reference device, a position of the reference device at the second time.

11 . A Global Navigation Satellite System (GNSS) receiver module for a first device in a real-time kinematic (RTK) positioning system, the RTK positioning system comprising the first device and a reference device, the GNSS receiver module comprising:

a GNSS receiver configured to

receive, from at least one GNSS satellite, GNSS signals, and

obtain first device GNSS measurements based on the GNSS signals;

a second receiver for receiving communications from the reference device; and

at least one processor configured to:

obtain, via the second receiver, first reference GNSS measurements, made at the reference device, for a first time;

obtain, via the second receiver, a position of the reference device, for the first time;

obtain, from the GNSS receiver, the first device GNSS measurements, made at the first device, for a current time;

calculate a first relative position of the first device, for the current time, relative to the position of the reference device, for the first time;

obtain, via the second receiver, second reference GNSS measurements, made at the reference device, for a second time, wherein the second time is subsequent to the first time;

calculate a position change of the reference device, from the first time to the second time, by comparing the first reference GNSS measurements and the second reference GNSS measurements; and

calculate a second relative position of the first device, for the current time, relative to the position of the reference device, for the second time, by combining the first relative position and the calculated position change of the reference device, wherein calculation of the second relative position is configured to begin before the second reference GNSS measurements are obtained to reduce a latency in calculating the second relative position of the first device.

12 . The GNSS receiver module of claim 11 , wherein calculating the second relative position occurs before or without obtaining, from the reference device, a position of the reference device at the second time.