Mobile reference station for GNSS positioning

1. A method for determining corrected positions of a global navigation satellite system (GNSS) rover using a GNSS base station and a GNSS reference station, each of the GNSS rover, the GNSS base station, and the GNSS reference station being configured for real-time kinematic (RTK) processing techniques, the method comprising: arranging the GNSS reference station at a first location; determining a first average position of the GNSS reference station at the first location using RTK corrections received from the GNSS base station and signals received from GNSS satellites; determining a first instantaneous position of the GNSS reference station at the first location using RTK corrections received from the GNSS base station and signals received from GNSS satellites; determining a first position of the GNSS rover using RTK corrections received from the GNSS base station and signals received from GNSS satellites; determining a first vertical correction based on the first average position and the first instantaneous position; determining a first corrected position of the GNSS rover based on the first position of the GNSS rover and the first vertical correction; thereafter arranging the GNSS reference station at a second location different from the first location; determining a second average position of the GNSS reference station at the second location using RTK corrections received from the GNSS base station and signals received from GNSS satellites; determining a second instantaneous position of the GNSS reference station at the second location using RTK corrections received from the GNSS base station and signals received from GNSS satellites; determining a second position of the GNSS rover using RTK corrections received from the GNSS base station and signals received from GNSS satellites; determining a second vertical correction based on the second average position and the second instantaneous position; determining a second corrected position of the GNSS rover based on the second position of the GNSS rover and the second vertical correction.

2. The method of claim 1 wherein the first and second corrected positions of the GNSS rover are also based on a scaling factor that is a function of a first distance between the GNSS rover and the GNSS reference station and a second distance between the GNSS rover and the GNSS base station.

3. The method of claim 1 wherein the first average position is determined from a plurality of first position measurements at the first location, and the second average position is determined from a plurality of second position measurements at the second location.

4. The method of claim 1 wherein the first instantaneous position is a single position measurement determined after a plurality of other position measurements that are used in determining the first average position, and the second instantaneous position is a single position measurement determined after a plurality of other position measurements that are used in determining the second average position.

5. The method of claim 1 wherein the first vertical correction is a vertical difference between the first average position and the first instantaneous position, and the second vertical correction is a vertical distance between the second average position and the second instantaneous position.

6. The method of claim 1 wherein the first instantaneous position is a most recent one of a plurality of position measurements used to determine the first average position, and the second instantaneous position is a most recent one of a plurality of position measurements used to determine the second average position.