## 1 Introduction  
GNSS technology is extensively utilized in geodetic monitoring studies of tectonic movements [1; 2; 3], landslides [4; 5; 6; 7; 8], and a variety of natural events which require high accuracy observations. Another field where GNSS technology is heavily employed is in structural health monitoring studies [9; 10; 11; 12]. GNSS measurement and processing methods exhibit variability in correspondence with evolving application domains. During high-precision applications, such as monitoring tectonic movements, static and long-term observations with the relative positioning method are generally used. Studies by [13; 14; 15] elucidate the use of long-term static GNSS measurements and relative positioning methods in monitoring tectonic movements. On the other hand, applications such as monitoring landslides or engineering structures can be applied with Real-Time Kinematic (RTK) or Precise Point Positioning (PPP) methods. The RT-PPP method [16], combines RTK and PPP methods for real-time landslide monitoring. The advantages of RT-PPP over RTK, particularly in overcoming limitations related to baseline length, are highlighted. Ref. [4] explained the monitoring of displacements caused by landslides using the network-RTK method. Ref. [17] tested the accuracy of the single base RTK GNSS method up to a 50 km baseline length. They found that single base RTK GNSS methods give similar results to the network RTK method up to 50 km. Ref. [18] investigated the potential of the GNSS PPP method for displacement monitoring. They used geodetic GNSS equipment and compared the PPP results with relative positioning results. The results showed that the PPP method, based on a 24 h observation period, can determine horizontal displacements up to 1.5 cm. [PERSON] et al. [19] investigated the use of PPP and PPP-AR methods in structural health monitoring studies. [PERSON] et al. [20] explained the applicability of the PPP method in monitoring engineering structures through shake table tests. Ref. [21] conducted studies on bridge monitoring using the RTK method, determining its accuracy in monitoring bridges. Above, the studies primarily focused on determining displacements geodetically using high-cost dual-frequency and geodetic multi-GNSS receivers and antennas. However, due to advancements in GNSS technology, low-cost GNSS receivers and antennas have emerged as viable alternatives to high-cost geodetic equipment, and these alternatives are now widely adopted. Initially, these receivers and antennas were introduced as single-frequency, and numerous studies have been conducted to assess the accuracy of single-frequency low-cost GNSS receivers and antennas up to the present day [22; 23; 24]. In recent years, there has been a shift towards dual-frequency and multi-GNSS low-cost receivers and antennas, replacing single-frequency systems. The significant advantage of low-cost GNSS receivers and antennas is their affordability, costing approximately 10 times less than geodetic counterparts. This cost advantage has not only increased the usage of such equipment in geodetic studies, such as monitoring tectonic movements, landslides, and engineering structures, but has also contributed to a more accurate displacement determination with the spatial resolution it offers. Several studies have investigated the usability and performance of low-cost GNSS equipment in geodetic monitoring and displacement determination. [25] conducted tests using the U-blox ZED-F9P receiver, low-cost U-blox ANN-MB-00 patch antenna, and geodetic Leica AS10 antenna to research the accuracy of low-cost GNSS receivers with the network RTK method. Although similar results to geodetic receivers were obtained with the low-cost U-blox ZED-F9P receiver, it was noted that satisfactory results were achieved only in clear sky conditions when the multipath effect was minimal. Ref. [26] aimed to test the accuracy of low-cost GNSS equipment for geodetic monitoring.