Why is positioning important?
The importance of positioning solutions for GPR array systems lies in the need for precise and accurate data collection. Precise positioning allows for the correct interpretation and analysis of the GPR data. It ensures that the data collected is representative of the actual subsurface conditions and structures. Without accurate positioning, the data collected may be misinterpreted or inaccurately represented, leading to incorrect conclusions.
Real-Time Kinematic (RTK) Global Navigation Satellite System (GNSS) and Total Station are positioning solutions that are often used with GPR array systems.
RTK GNSS
GNSS is a general term for global navigation satellite systems like GPS (United States), GLONASS (Russia), Galileo (European Union), and BeiDou (China).
RTK GNSS enhances the accuracy of GNSS positioning by using a network of fixed reference stations with known positions. These stations continuously monitor satellite signals and compute corrections for the errors. A mobile RTK receiver uses these corrections in real-time to improve its positional accuracy. RTK measurement technology is based on carrier phase observations and has a carrier phase differential measurement technology with fast and high-precision positioning functions. It can obtain the three-dimensional positioning results of the station in the specified coordinate system in real time, and has centimetre-level positioning accuracy.
Total Station
A Total Station is a modern surveying instrument that combines an optical unit with electronic distance measurement capabilities. By aiming at a point or a prism, it can automatically calculate distances, angles, and positions with high accuracy. Without a prism, Total Stations can measure up to around 1,000 meters, while using special prisms extends the range to 7–10 kilometers. In practice, however, surveys are usually carried out over shorter distances, since a clear line of sight and good visibility are essential for reliable results.
In conclusion, precise positioning solutions like RTK GNSS and Total Station are crucial for GPR array systems to ensure the accuracy and reliability of the data collected. They allow for precise mapping and detection of subsurface structures, which is essential in applications like, for example, utility, archaeology and construction.