Abstract:
Precise point positioning can be considered as an alternative solution for the
traditional GNSS positioning techniques with the use of a single GNSS receiver.
Precise Point Positioning (PPP) has started to make positioning utilizing
undifferenced carrier phase and pseudo-range observations. The main objective of this
research was to examine the accuracy variation between Different levels of PPP
solutions such as Ultra-rapid(observed half), Rapid and Final, which are provided by
the International GNSS service .so in this study, five GNSS observation points were
established in Sabaragamuwa University of Sri Lanka premises. After Data were
collected as three-hour observations for all five points, The collected data were
processed using the RTK LIB and CSRS PPP According to the result obtained, CSRS
PPP and RTK LIB results showed a significant difference, so after the same data were
processed using the DGNSS method in order to further confirm which platform is best
one. For further assessment, Distance and Height differences between points were
measured. However, in the end, CSRS PPP showed the best performance for the three
PPP product levels. It was concluded that centimeter-level accuracy could be achieved
in static mode while Final Product showed better accuracy than others. Rapid and
Ultra Rapid products showed almost equal accuracy horizontally. Accuracy for the
Up direction was led by the Ultra-rapid (observed half) product, followed by the Final
and Rapid products, respectively.
