Abstract:
Loss of signal reception is a critical issue in Global Navigation Satellite Systems
(GNSS) that can lead to degraded positioning accuracy. Satellite signal blockage,
jammers, and continuous cycle slip (CS) detection are some of the primary
reasons for signal loss. In this research, we focused on detecting the effects of CS
on GNSS observations at ISM Diyathalawa, a location with a clear sky view.
Atmospheric conditions are the primary cause of CS, which can lead to sudden
changes in carrier phase measurements, resulting in errors in positioning
solutions. The research aimed to achieve two major objectives: (1) enhancing the
accuracy of the open-source software RTKLIB, and (2) approaching the accuracy
of commercial software such as Leica Infinity. Although most commercial
software can detect cycle slip, their prices are typically expensive. Thus, the study
focused on using RTKLIB to enhance positioning accuracy when continuous
cycle slip results in satellite signal loss. To accomplish the research objectives,
the team added a new feature that includes the satellite vehicle number for GPS
satellites, called "RTKLIB New," which is also user-friendly. The methodology
of the research involved removing satellites which are consisted longer period
signal lost due to the cycle slip, through precise point processing (ppp) and
evaluating the accuracy changes in RTKLIB 2.4.2 and RTKLIB New. Based on
the ISM Point known coordinate, RTKLIB New fulfilled the aims and provided
a
54% positional accuracy improvement compared to RTKLIB 2.4.2.
Furthermore, 24-hour observations showed that the RTKLIB New accuracy was
comparable to that of Leica Infinity positional accuracy. These findings can be
useful in improving the accuracy of GNSS positioning in areas prone to
continuous cycle slip and clear sky areas.
