Surveying equipment plays a key role in collecting accurate and reliable data for various purposes. Among the commonly used surveying instruments are Total Station and GNSS receivers. The two devices differ in their setup and operational processes, as well as in their accuracy and limitations.
Setting up a Total Station involves occupying a known coordinate point, laying out the tripod, and pointing towards a surveying prism to obtain measurements. In contrast, setting up a GNSS receiver is faster and involves attaching the receiver to a pole and connecting it to a controller. However, GNSS receivers struggle with obstructions such as tree and canopy coverage, while the Total Station is more accurate but may have errors due to relative distance measurements.
When surveying a residential home, using a Total Station around the house may be time-consuming, while using a GNSS receiver provides more control and mobility. In the summer when there is a lot of leaf coverage on trees, using a GNSS receiver becomes difficult due to tree canopies creating a forest ceiling. However, with the Leica gs18i GNSS receiver, image capture aids in data collection, providing centimeter-level accuracy in areas where the GNSS receiver is obstructed.
Comparing the accuracy of the devices, Total Station is more accurate with a difference of about one to one and a half millimeters, while GNSS receivers provide horizontal discrepancies of seven hundredths of a foot. Total Station uses a local coordinate system, while GNSS receivers provide geodetic positions. In assessing the accuracy of the GNSS receiver, point number one and point number two need to be observed and inversed between.
In conclusion, choosing the right surveying instrument depends on the specific requirements of the job at hand. Total Station may be more accurate but require more time and setup, while GNSS receivers provide more flexibility but struggle with obstructions. It is important to carefully consider all factors and limitations before selecting the appropriate tool for the task.