# Sampling Rate Impact on Precise Point Positioning with a Low-Cost GNSS Receiver
## 1 Introduction  
With the advance and improvement of the global navigation satellite systems (GNSS) and geodesy, new receivers with different characteristics have appeared. In this sense, the new low-cost GNSS receivers are a reality in geodetic works. These receivers first appeared in the 1990s as a cheaper alternative to the high prices of geodetic receivers [1]. The low-cost GNSS receivers are sometimes called \"high sensitivity\" due to their capability of tracking -160 dB [2], which causes the receiver to track weak signals that were degraded by objects surrounding the antenna [1]. The low-cost GNSS receivers have been implemented and tested in several ways, such as structure monitoring [3; 4; 5], RTK mode under ISO [6], geodetic baseline [7; 1], comparison of precise point positioning (PPP) and static relative methods [8], meteorology and mapping [2; 9], in different technologies [10], by testing the performance with a single frequency by constraining the distance from of the baseline [11], geodetic monitoring [12], etc. Based on the above, it is common to use the static relative method using carrier phase observations with at least two receivers simultaneously (one rover and the other as a reference with well-known coordinates) to obtain high accuracy [13]. The collected data could be processed with commercial or scientific GNSS software depending on the work objective (i.e., topography could be processed with the Topcon Tools software or crustal deformation purposes with the GAMIT/GLOBK software in the same way as when using commercial software, as the user does not need an advanced knowledge of GNSSprocessing methods, unlike when using scientific software where the user needs a complete and advanced knowledge of the topic) [14]. In the state of the art, the main works are related to testing the performance of low-cost GNSS receivers using the static relative method [8; 15] and the RTK (real-time kinematic) method [6; 16]. A new strategy implemented in this research paper is using the PPP technique to test the performance of GNSS measurements with low-cost receivers when they are processed with online software with different sampling frequencies. The PPP technique is well known as a potential alternative to relative positioning as it can achieve precision in the order of millimeters [13; 17]. The PPP technique for estimating geodetic networks and reference stations using a single receiver was proposed by [18] and improved by [19]. This method provides centimeter to millimeter levels and accurate positioning (sometimes with the increase in the geomagnetic storm intensity, some stations suffer a degradation of positioning at high-altitude regions [20]) within a consistent global reference frame [21]. Some advantages are notable, such as the use of a single receiver, highly accurate positioning, real-time PPP, compatibility of use in urban canyons [22] and their suitability for monitoring structures. Due to the achievable millimeter precision, and the ability to achieve measurements at high sampling frequencies, the PPP technique provides better dynamic analysis of structures [17; 23; 24]. More recently, as a result of the improvement of some components (such as antenna and receiver capability) in the geodetic receivers (including the low-cost GNSS receivers), the high sampling rate in data collection and processing is possible [25]. According to [26], PPP-based high-rate GNSS started to be used in seismology, structural health monitoring of civil infrastructure [27], etc. Based on this fact, the main objective of this research is to compare the performance and suitability in the positioning precision when using different sampling rates to determine which of them achieves the best positioning, when using the PPP method in static and kinematic mode, with a low-cost GNSS receiver. The solutions of a geodetic GNSS receiver will be taken as a reference.