A Conceptual Framework for Server-Based GNSS Operations

Abstract

The diversification of Global Navigation Satellite Systems (e.g. the current and modernized GPS, the revitalized GLONASS, the planned Galileo and Compass), is an opportunity for engineers, surveyors and geodesists because of expected improvements in positioning accuracy, operational flexibility, redundancy, and quality assurance. Recent research activities include new algorithms for multiple frequency ambiguity resolution, software-based receivers for reconfigurability, network-wide corrections for utilising redundancy, reversed real-time kinematic schemes for quality/accuracy improvement, and a wide range of rover-side applications. This paper discusses the integration of these “pieces” of work into a new framework and facilitates information and communication technologies in order to derive benefits from network infrastructure such as continuously operating reference stations and local/regional GPS networks. Operational models are proposed for precise point positioning and real-time kinematic services including “near real-time” applications, which require an optimal design to balance the computational overhead with data communication latency. The proposed framework is designed to be a comprehensive, serverbased, and thin-client platform. It provides end-users with “out-of-the-box” services. End-users should be able to obtain extensive GNSS capabilities and high productivity without conventional constraints such as an expensive set of receivers, proprietary data formats, user-installed carrier phase processing software, incomplete interoperability, limited communication links, etc. The framework also adopts up-to-date database technologies and web technologies that enable servers to perform data management and spatial analysis, while end-users are able to syndicate data and create their own business models. The framework has been applied to Sydney Network (SydNET), a network of continuously operating reference stations located in Sydney, Australia. It is expected that the new framework will be versatile enough to cope with a diverse range of user performance requirements and the operational requirements for communications and positioning computations.