Improved atmospheric modelling for large scale high-precision positioning based on GNSS CORS networks in Australia

Abstract

This contribution describes a recent Australian Research Council (ARC) project funded under the ARCLinkage Scheme. The research team comprises researchers from RMIT University, UNSW, University of Melbourne, Spatial Information Infrastructure and the Department of Lands, NSW. The aim of the project is to enhance the utility of continuously operating reference station (CORS) networks in the states of Victoria and New South Wales by developing improved atmospheric correction models to support high accuracy, real-time positioning even when the density of reference stations is insufficient for standard operational GPS techniques such as RTK (‘real-time kinematic’). Many applications of Global Navigation Satellite System (GNSS) technology, such as surveying, mapping and precise navigation, require real-time positioning accuracies to centimetre levels. To support these applications, many countries are establishing dense CORS networks with stations, positioned typically a few tens of kilometres apart. However, for Australia with its large and sparsely populated landmass, such dense networks cannot be justified economically. This ARC project will investigate enhancements of sparse networks to maintain similar levels of accuracy as dense CORS networks. It will seek a better understanding and modelling of atmospheric conditions, currently a major limitation in the use of sparse networks for high accuracy techniques. This paper will describe the status of current developments in CORS network infrastructure in Australia, namely GPSnet in Victoria and SydNet in New South Wales. The major research components of the project will be outlined and the technical and practical challenges will be discussed, including some methodologies that will be investigated.