## 1 Introduction  
The application of precision agriculture practices helps save operational costs and reduce the environmental burden, resulting in increased and improved food production while optimising the whole agricultural process [1]. Today, agriculture is confronted with a number of requirements, the introduction of which cannot be done without a significant modification of the current concept of production. A significant means of optimising inputs is the satellite navigation of agricultural machinery. In addition to time accuracy and enabling an optimised follow-up of individual work operations, more and more emphasis is placed on the level of accuracy of navigation devices. Most precision agriculture operations refer to the operation, guidance and control of machines to carry out agricultural tasks. The reliable and accurate positioning of these autonomous machines plays a key role in the set of operations comprising guidance, detection, action and mapping [2]. High accuracy and reliability will also be essential for the advent of robotic structures. Although people will continue to be involved in the decision-making process, it can be assumed that, with the growing intelligence of machines, their better interconnection and the accuracy of interventions, precision agriculture will become more and more automated. Furthermore,any deviation in accuracy at the beginning of the plant establishment process means introducing errors into all subsequent operations; in particular: increasing overlaps, higher costs, fuel consumption, seeds and chemicals and the carbon footprint. Confidence in the accuracy of RTK receiver positioning is essential in modern agriculture, as its reduction or even failure may negatively affect the benefits of the system. As described by the authors of reference [3], the benefits include the reduction of driver fatigue (guidance system reduces the effort required to maintain the correct machine route); increased productivity (allowing higher operating speed, faster headland turns and cost savings); cost reduction (there is a significant reduction in overlaps and omissions); reduced environmental impact; efficient overnight work; higher safety; better quality (the driver can focus on quality control) and improved ergonomics (reduction of stress of machine operators). Without precise positioning, autonomous navigation is dangerous for machine integrity and, more importantly, for workers. Precise positioning can be assured by RTK methods that have already proved successful in a number of precise agriculture applications [1]. The possibility of measuring positions using the GNSS (Global Navigation Satellite System) laid the foundation for precise agricultural techniques. Combining the GNSS with RTK (Real-Time Kinematic) allows for a significant improvement of these methods [4; 5]. Nowadays, the RTK method is one of the most accurate navigation systems available on the market, which can be used to obtain an absolute position anywhere on Earth's surface with sufficient signal reception from GNSS satellites and a correction signal from a nearby reference station, called a base station [6; 7]. RTK positioning can be widely used in different applications of precision agriculture, and it has already brought about positive effects. Unmanned Aerial Vehicles (UAV) equipped with a camera can be useful in providing orthophotographs and improved resolution images. Ortho-mosaics can be generated based on images obtained from UAVs capable of flying over considerable large areas in a short time [8]. The georeferencing process constitutes one of the major challenges in the generation of ortho-mosaics. The authors of reference [9] suggested that, when the RTK method is applied on UAVs, positioning errors can be reduced and direct georeferencing ensured. In reference [10], an expensive RTK receiver placed on a drone was used to generate a detailed volumetric 3D model of plants. A drone with an RTK receiver was used to design the application of automatic transport to the exact location [11].