# Investigation of Static and Kinematic Surveying Performance of Handheld GNSS Receiver +
## 1 Introduction  
The Global Navigation Satellite Systems (GNSS) has become a widely used standard positioning tool today. It is possible to achieve different levels of accuracy depending on the method applied in satellite-based positioning systems. For example, for low accuracy requirements at the meter level, standard navigation-type receivers that can determine absolute position using code measurements are sufficient, while for centimeter-millimeter accuracy requirements, the relative method using carrier-phase measurements must be applied. Today, the Precise Point Positioning (PPP) technique, which does not require additional reference station observation but can produce the accuracy provided by the relative method, has found use in many applications [1, 2, 3, 4]. This technique, which combines raw data collected with a single GNSS receiver and precise satellite clock & orbit corrections, enables 3D positioning with an accuracy of a centimeter-millimeter level, depending on occupation time, used receiver and equipment, number of frequencies (single or multi-frequency), tracked satellite constellations and environmental survey conditions (multipath, etc.). However, to achieve this accuracy, a long convergence time of 15-30 min is needed [5]. This issue limits the use of the method in real-time applications. Recently, an ambiguity-fixedsolution has been obtained by using satellite phase bias values during the PPP solution. With this approach, called Precise Point Positioning-Ambiguity Resolution (PPP-AR), accuracy has increased and convergence time has also been shortened [6,7]. In order to obtain a high-accuracy position with both the relative method and the PPP technique, code and phase measurements collected with geodetic-type receivers should be used. This also means using at least 2 geodetic receivers for the relative method and at least 1 for PPP. Although the prices of these receivers vary depending on manufacturer policies, they can reach quite high values (up to 20K USD or even more each). On the other hand, as a result of the developments in hardware and informatics technologies, raw GNSS measurements (code, Doppler, carrier-phase observations, and others) can now be collected with smartphones and tablet computers. These types of devices have attracted the attention of the academic community, and the positioning performances of smartphones and tablet computers have been investigated in many academic studies [8, 9, 10, 11]. These studies demonstrated that better accuracy can be achieved, especially when carrier phase data is collected with geodetic-type antennas. On the other hand, there are some limited studies on the usability of handheld GNSS receivers for high-accuracy positioning [12, 13, 14]. However, when these studies were investigated, it was seen that the collected raw data was not provided by the manufacturer with standard protocols, and it is not commercially available. Thus, the researchers collected the data with their in-house software. This situation has also restricted the widespread use of such devices in geodetic applications. In 2018, Garmin Ltd. provided the raw GNSS data commercially with the Garmin handheld receiver, which is mainly used for navigation, outdoor, marine, and sports activities, and this paved the way for using such devices in high-accuracy positioning. There are few studies conducted with this device in the literature. In one of these studies carried out by [PERSON] et al. [15], the raw data was collected using an external antenna in static and kinematic modes with both GPSMAP 66 handheld and a smartphone with an Android operating system. In the study, it was observed that differential positioning accuracy better than 1 m RMSE could be achieved with a handheld GNSS receiver in vehicular mode. In another study carried out by [PERSON] et al. [16], the performance of the Garmin GPSMAP 66 sr handheld GNSS device was investigated, and it was revealed that it provided positioning with centimeter accuracy in dual-frequency GPS&Galileo PPP static mode.