New Concept of Smart UAS-GCP: A Tool for Precise Positioning in Remote-Sensing Applications

Abstract

Today, ground control points (GCPs) represent indispensable tools for products’ georeferencing in all the techniques concerning remote sensing (RS), particularly in monitoring activities from unmanned aircraft system (UAS) platforms. This work introduces an innovative tool, smart GCPs, which combines different georeferencing procedures, offering a range of advantages. It can serve three fundamental purposes concurrently: (1) as a drone takeoff platform; (2) as a base station, allowing the acquisition of raw global navigation satellite system (GNSS) data for post-processed kinematic (PPK) surveys or by providing real-time GNSS corrections for precision positioning; (3) as a rover in the network real-time kinematic (NRTK) mode, establishing its position in real time with centimetric precision. The prototype has undergone testing in a dedicated study area, yielding good results for all three geodetic correction techniques: PPK, RTK, and GCP, achieving centimeter-level accuracy. Nowadays, this versatile prototype represents a unique external instrument, which is also easily transportable and able to connect to the GNSS RING network, obtaining real-time positioning corrections for a wide range of applications that require precise positioning. This capability is essential for environmental applications that require a multitemporal UAS-based study. When the real-time RING data are accessible to the scientific community operating in RS surveying, this work could be a helpful guide for researchers approaching such investigations.

Drones and Real-Time Kinematic Base Station Integration for Documenting Inaccessible Ruins: A Case Study Approach

“…In such a case, it becomes interesting to understand the most appropriate approaches on how to conduct the survey, which drone to prefer, and which methods to implement to integrate the data resulting from the different instruments. Certainly, the possibility of using a base GNSS receiver coupled with a UAV makes it possible to take georeferenced photographs, which then allows direct georeferencing to be performed within the photogrammetric process [9,10]. In addition, the use of drones coupled with a ground base station, exploiting Real-Time Kinematic (RTK) or Post-Processing Kinematic (PPK) technologies, would result in a greater accuracy of such data [11][12][13].…”