Performance analysis of ISKANDARnet: a research-based network RTK positioning system

Abstract

GNSS positioning within the equatorial region suffers from distance-dependent errors due to severe atmospheric delays, which results in difficulty for the network ambiguity resolution process. Hence, it is a challenge to maintain the capability of centimetre-level positioning in this region. Subsequently, a network of Continuously Operating Reference Stations (CORS) situated in the developing region of Iskandar Malaysia, known as ISKANDARnet, has been developed by Universiti Teknologi Malaysia (UTM) as a research platform to support academic activities and high-precision positioning applications. The ISKANDARnet with its Network-based Real-Time Kinematic (N-RTK) technique provides a means to meet the challenge. In this study, the performance of ISKANDARnet N-RTK has been analysed in terms of positional accuracy, performance of ambiguity resolution, and effectiveness of network corrections by conducting real-world-scenario tests: (i) at different user locations, (ii) in varied observation sessions, and (iii) by external assessment with the national commercial N-RTK system, i.e., the Malaysia Real-Time Kinematic GNSS Network (MyRTKnet). The results indicated that significant changes in ambiguity resolution occur at different user locations and observation sessions, providing insight into the varying distance-dependent errors. Moreover, the positioning accuracy agrees to within centimetre-level of the national commercial N-RTK system.

Keywords::

• network-based RTK
• equatorial region
• ISKANDARnet

Acknowledgements

The authors would like to express their gratitude to MOSTI, UTM, FRGS (Vote No. 4F182) for the financial support throughout the project and the Department of Survey and Mapping Malaysia (DSMM) for providing MyRTKnet data.