Two different methods, absolute and relative positioning, are used in determining point positions with GNSS techniques. Precise Point Positioning (PPP) technique, which is one of the absolute positioning methods, is a powerful position determination method.

In this study, the accuracy of PPP has been investigated in terms of session durations, online web services, satellite visibility and urbanization. For this purpose, three of CORS-Tr stations were selected in residential, semi-residential and non-residential areas. Consecutive 31-day data of these stations for the year 2019 were downloaded from server. The 31-day consecutive coordinates were obtained by sending the downloaded RINEX data to AUSPOS. The average of these coordinates was considered as true quantity value. Then, the RINEX data were binned four groups as 1 h, 2 h, 4 h, 6 h. The binned data were evaluated with web-based online PPP services (CSRS-PPP, magicGNSS, APPS) and compared with the true quantity value. In conclusion, it was seen that the best result was obtained in the non-residential area and CSRS-PPP yielded the most accurate results for all session durations.

GNSS技术使用两种不同的方法（绝对和相对定位）来确定点位置。精确点定位（PPP）技术是一种绝对的定位方法，是一种强大的位置确定方法。

在这项研究中，已根据会话时长，在线Web服务，卫星可见性和城市化程度对PPP的准确性进行了研究。为此，在住宅区，半住宅区和非住宅区选择了三个CORS-Tr站。这些年的连续31天数据从服务器下载的2019年。通过将下载的RINEX数据发送到AUSPOS获得31天连续坐标。这些坐标的平均值被认为是真实的数量值。然后，将RINEX数据分为1h，2h，4h，6h四组。使用基于Web的在线PPP服务（CSRS-PPP，magicGNSS，APPS）评估合并后的数据，并将其与真实数量值进行比较。结论，