GNSS OR TOTAL STATION FOR A TOPOGRAPHIC SURVEY

A topographic survey is considered the first step in any construction or developmental project. It is very crucial for planning, design, and construction as it forms the basis of the architect’s design and enables them to accurately design their projects to be tailored down to their client’s specifications or needs and the unique features of the land. As such, inaccurate topographic survey results can cause costly delays or enormous errors in construction projects.

In the past, most topographic surveys were done with total stations but due to its constraints, surveyors are not f inding it more convenient to use GNSS RTK equipment for their topographic survey work. However, GNSS equipment faces some challenges like its inability to work properly in a covered terrain. Hence, to achieve maximum accuracy in a topographic survey, it is best to know the strengths and weaknesses of both equipment in order to make an informed decision about the choice of equipment for a project.

Comparison of Total Station and RTK GNSS Equipment

Distance Measurement

When measuring short distances, the electronic distance measuring (EDM) component of the total station is used with an accuracy of 5-10 mm per km, and can also measure points in areas that the RTK could not reach like underground mines or tunnels as the GNSS RTK requires a clear view of the sky for its measurement. While the GNSS equipment measures with an accuracy of 1-2 cm in terms of short distances measurement. But when it comes to long distances, GNSS is best suited as it does not require line of sight from point to point.

High Precision

Total Station is known for its high precision and is ideal for projects that require highly accurate measurement, however, it is limited by visibility. While the GNSS RTK can measure in areas with limited visibility, it is limited in terms of high precision as it depends on satellite signals which might be affected by signal blocking, thereby reducing the accuracy.

Time Consumption.

In general, RTK GNSS surveys can be done faster compared to total station surveys because there is no need to move the tripod from station to station, there is no need for line of sight and you do not need to reference your last equipment station.

In summary, both the total station surveying and the GNSS RTK surveying have their advantages and disadvantages, which is why it is better for the surveyor to know the strengths and weaknesses of both so as to make an informed decision when choosing equipment for any site and specific project.

TOPOGRAPHIC SURVEY IN NIGERIA USING GNSS RTK OR TOTAL STATION EQUIPMENT

TOPOGRAPHIC SURVEY IN NIGERIA USING GNSS RTK OR TOTAL STATION EQUIPMENT