BASE SHIFT in Nuwa

[GNSS Tersus]

In ‘Auto Start’ mode for base station, if the base is moved, or re-started at an unknown point, base shift should be performed to ensure the points collected under the current base station is consistent with that before the base is moved or re-started.

In Nuwa, when performing a base shift, you can choose to use the current base point to calculate the shift amount, or you can choose to use survey point under current base to calculate the shift amount. They are essentially the same, and will apply the shift amount to all the survey points under current base, so that the current plane coordinate datum remains the same as before moving or re-starting.

If the Auto Start base station is re-started at the same location, Nuwa prompts to detect the movement of the base station after the rover is fixed. At this time, the current base station Base1 and the base station Base0 before the restart are used for the calculation. Convert the coordinates of Base0 to control point coordinates, select Base1 as the GNSS point and click [Calculate].

If the base station is moved such as setting the base station at a survey point before the base station moves. At this time, use the current base station Base1 and the survey point before the movement for the calculation. Convert the coordinates of the survey point to control point coordinates, select Base1 as the GNSS point and click [Calculate].

If the base station is moved such as setting the base station at any point. At this time, use the current base station Base1 and the same survey point under the base station Base0 before the movement for the calculation. Convert the coordinates of the survey point under Base0 to control point coordinates, select the survey point under Base1 as the GNSS point and click [Calculate].

After the base shift calculation result is applied, the shift amount in the three directions of NEZ will be saved as a property in the point details of the Base point, and the shift amount in the three directions of NEZ will be directly added to the coordinate of the survey points under the Base. This means that if you want to perform the second base shift calculation based on the first base shift, the results of selecting the base point and the survey point are different. Selecting the base point will lead the calculation based on the original coordinates of the base, and selecting the survey point will lead the calculation based on the result of the first base shift.