Performance analysis of web-based relative and absolute positioning services

GNSS is being used effectively to precise position for many measuring and geodetic purposes at the present time. Although there is an increasing variety of these systems including the post-processing calculations in terms of number, quality and features and many different techniques are developed to determine position, these techniques are still based on relative and absolute position determination principles. Precise positioning which both of these approaches intend to derive requires user experience and scientific or commercial software with costly license fees. However, in recent years important alternatives to this software that are user friendly and offer free web-based online positioning service have become widely used in geodetic purposes. Therefore in this study, these services' accuracy and performance research has been conducted in ground control points that have different features considering their development dynamics. Particularly, the accuracy of the static GPS data of these services that serve with the principle of precise point positioning (PPP) has been investigated.