Galileo navigation system has significantly expanded satellite constellation over the last few years and now serves with 22 satellites in three orbital planes. The development of the Galileo is not only limited to the number of satellites in the space segment, but also the quality of the IGS MGEX products produced by different Analysis Centers has increased gradually and brought up the topic of investigation of the accuracy and precision of the Galileo-only positioning. However, almost all of the studies on Galileo-only positioning in the literature have been performed with Precise Point Positioning method and comprehensive studies with the relative positioning technique are quite a few. In this study, the development of the accuracy and precision of the Galileo from 2016 to the end of 2019 (4 years) has been investigated for the first time by means of relative positioning technique. For this purpose, data of eight GNSS stations selected from the IGS MGEX network were obtained and analyzed with GAMIT/GLOBK software as GPS-only and Galileo-only, separately. Using the daily solutions obtained from both navigation systems, time series were produced and the differences between them were compared in order to reveal the Galileo accuracy. According to the results, the accuracy of the Galileo was variable during the experiment and it could be examined in three periods. The averages of 3D positioning error in the first period (2016-2017) is 14.92 mm and improved by 56%, and decreased to 6.55 mm in the second period (2017-2018), and then improvement at 23% in the third period (2018 to the end of 2019) and decrescent to level of 5.13 mm on average for all stations. Similarly, standard deviations obtained from Galileo increased during the experiment and during the 3rd period it was closed to a few mm with GPS. It was concluded that the accuracy and precision of the Galileo showed parallel development and the development was directly related to the number of satellites in the Galileo constellation, and as a result, nowadays, Galileo-derived coordinates are close to the coordinates obtained from the GPS by a few mm.

过去几年中，伽利略导航系统极大地扩展了卫星星座，目前在三个轨道平面上为22颗卫星提供服务。Galileo的发展不仅限于空间部分的卫星数量，而且不同分析中心生产的IGS MGEX产品的质量也逐渐提高，并提出了研究卫星精确度和精确度的话题。仅伽利略定位。然而，文献中几乎所有关于仅伽利略定位的研究都是使用精确点定位方法进行的，并且相对定位技术的综合研究也很多。在这个研究中，通过相对定位技术首次研究了伽利略从2016年到2019年底（4年）的精度和精确度的发展。为此，分别获取了从IGS MGEX网络中选择的八个GNSS站的数据，并分别使用GAMIT / GLOBK软件（仅GPS）和仅Galileo进行了分析。使用从两个导航系统获得的每日解决方案，产生了时间序列，并比较了它们之间的差异，以揭示伽利略的准确性。根据结果​​，伽利略的准确性在实验过程中是可变的，可以在三个时期内进行检查。第一阶段（2016-2017）的3D定位误差平均值为14.92 mm，提高了56％，第二阶段（2017-2018）的平均3D定位误差降至6.55 mm，然后在第三阶段（从2018年到2019年底）提高23％，并且所有站点的平均下降到5.13毫米。同样，在实验期间，从伽利略（Galileo）获得的标准偏差也有所增加，在第3阶段，使用GPS将其偏差缩小到几毫米。结论是，伽利略的精度和精度显示出平行发展，并且发展与伽利略星座中的卫星数量直接相关，因此，如今，伽利略派生的坐标已接近于从GPS获得的坐标几毫米。