Tech Chat | How to make your surveying more accurate? – Importance of Grid Shift

In daily surveying, we usually set up base stations on known points. What if there are no known points or the known points are far apart in some large-scale projects? How can we ensure the accuracy when shift or re-start the base station?

Relative accuracy & Absolute accuracy

In this situation, first we need to clarify the definition of Relative accuracy and Absolute accuracy. Absolute accuracy is the comparison between the measured points and the known points, while relative accuracy is the comparison between multiple measurement points.

So under this no known points project, what we should guarantee is the relative accuracy results. But caused by the single solution on GNSS Receiver is meters accuracy, each time when setup base, the base value also has the meters shift. Then the RTK rovers results will also have much difference if compared even at the same point.

Therefore, in projects without known points, what we need to ensure is the relative accuracy of the survey results. But since the single-point solution of most RTK receivers is meter-level accuracy, every time you set up the base station with auto-base mode on the same point, the base positioning may have a meter-level offset. Then the results for RTK rovers can vary greatly even when compared at the same point.

How Grid Shift helps in this situation?

In view of this situation, the method Grid Shift was born.

Assuming that you are starting a survey at the site for the first time, you can start the base station in auto-base mode, and then conduct the survey tasks normally.

At the next day when the base station needs to be started again, you can directly select the previously measured point as the base station point to start the base station, so as to ensure the relative accuracy of the two operations. In the follow-up tasks of this project, you can continue to use this method to start the base station to ensure relative accuracy.

How to use Grid Shift function: SingularPad Tutorial | Calibrate Point

If the local known points coordinates are obtained later in the project, you can also use the localization function to shift all the measured points of the current project to the known point coordinate system.

How to use Localization function: SingularPad Tutorial | Localization

SingularXYZ SingularPad field surveying software can help you carry out measurement projects smoothly, learn more:
https://www.singularxyz.com/SingularPad.html