(2018) aimed to assess and compare the multipath and receiver noises for GPS, BeiDou, GLONASS, and Galileo data by implementing the zero-baseline approach. Multi-GNSS performance evaluation was also the objective of the study proposed by [PERSON] et al. (2018). Their work focused on the contemporary use of four constellation data and on the implementation of different data combinations. MGEX data were also used in the paper of [PERSON] et al. (2018). In this case, the aim of the work was the assessment of the precise orbits and clocks for Galileo, BeiDou, and QZSS. This was performed by comparing the outcomes of different analysis centers and laser satellite ranging. Galileo data were involved also in real-time multi GNSS applications. [PERSON] et al. (2018) worked on real-time kinematic (RTK) based both on carrier-phase measurements and on pseudorange measurements acquired from the IOV Galileo satellites (already able to transmit navigation data). They tested different combinations considering only the Galileosignals and the combined Galileo and GPS signals and found that the Galileo and GPS combination could lead to an instantaneous ambiguity resolution. [PERSON] et al. [28] proposed a multi GNSS single-frequency real-time kinematic study, while [PERSON] et al. [29] focused their attention on the real-time multi GNSS precise orbit determination, clock estimation, and positioning. Galileo data were also tested for attitude estimation (e.g., [30; 31]) and included in an online service devoted to the validation of multi-GNSS orbits by means of the satellite laser ranging [32]. Lastly, Galileo data were measured for GNSS reflectometry polarimetric acquisitions over boreal forests [33]. Thus far, this paper has shown the rigor with which, in many studies, the Galileo data were tested and assessed, especially in static sessions of measurements. However, to the authors' knowledge, there are no examples of kinematic trajectory comparisons between the Galileo positioning performance and GPS- and GLONASS-derived trajectories, by using a reference trajectory derived from a precise Mobile Mapping System (MMS) as a benchmark. Specifically, in this paper, we propose a preliminary (and empiric) single-frequency kinematic performance assessment of Galileo, GPS, and GLONASS data acquired by using a Leica GS14 receiver, with reference to a trajectory estimated with MMS equipped with a POS/LV (Position and Orientation System for Land Vehicles), produced by the Applanix corporation. The Applanix system features a filtering system capable of integrating GNSS measurements with an IMU (inertial measurement unit) in order to guarantee a stable, reliable, and repeatable positioning solution for land-based vehicle applications [34] and to ensure better positioning performance with regard to GNSS-only measurements (complementary and surpassing property [35]). The performed trajectory comparisons were produced in such a way as to consider, for the three positioning systems, all the possible combinations (with four, five and six satellites for each considered constellation), by simulating a reduced operability for GPS and GLONASS. In this way, all the real and comparable working conditions, among the three different constellations, were simulated for a real case study. All the positioning solutions (and trajectories) were computed by means of the Free and Open-Source Software (FOSS) RTKLIB. RTKLIB is an open-source program package for standard and precise positioning and consists of a portable program library and several APs (application programs) already used in previous scientific communications [36; 37; 38; 39; 40]. It supports: (1) standard and precise positioning algorithms with GPS, GLONASS, Galileo, QZSS, BeiDou, and SBAS; (2) single, DGPS/DGNSS, Kinematic, Static, Moving-Baseline, Fixed, PPP-Kinematic, PPP-Static, and PPP-Fixed positioning modes with GNSS for both real-time and post-processing (further details can be found in [41]).