1) National School of Surveying, University of Otago, 310 Castle Street, 9016 Dunedin, New Zealand, email: robert.odolinski@otago.ac.nz 2) Department of Spatial Sciences, GNSS Research Centre, Curtin University, Perth, Australia 3) Delft University of Technology, Delft, The Netherlands Low-Cost, High-Precision, Single-Frequency GPS-BDS RTK Positioning 1 Robert Odolinski 1 , Peter J. G. Teunissen 2,3 2 3 Abstract The integration of the Chinese BDS with other systems, such as the American GPS, 4 makes precise RTK positioning possible with low-cost receivers. We investigate the performance 5 of low-cost ublox receivers, which cost a few hundred USDs, while making use of L1 GPS + B1 6 BDS data in Dunedin, New Zealand. Comparisons will be made to L1 + L2 GPS and survey-grade 7 receivers which cost several thousand USDs. The least-squares variance component estimation 8 (LS-VCE) procedure is used to determine the code and phase variances and covariances of the 9 receivers and thus formulate a realistic stochastic model. Otherwise the ambiguity resolution and 10 hence positioning performance would deteriorate. For the same reasons, the existence of receiver- 11 induced time-correlation is also investigated. The low-cost RTK performance is then evaluated by 12 formal and empirical ambiguity success-rates and positioning precisions. It will be shown that the 13 code and phase precision of the low-cost receivers can be significantly improved by using survey- 14 grade antennas, since they have better signal reception and multipath suppression abilities in 15 comparison to low-cost patch antennas. It will also be demonstrated that the low-cost receivers can 16 achieve competitive ambiguity resolution and positioning performance to survey-grade dual- 17 frequency GPS receivers. 18 Keywords Low-cost Receiver, Multi-GNSS, Real Time Kinematic (RTK) positioning, Least- 19 squares variance component estimation (LS-VCE), Time-correlation 20 21 Introduction 22 In the past few decades, the American Global Positioning System (GPS) has been the primary 23 positioning tool for many applications. The integration with the emerging Global Navigation 24 Satellite Systems (GNSSs), such as the Chinese BeiDou Navigation Satellite System (BDS), can 25 Odolinski, R. and Teunissen, P. 2017. Low-cost, high-precision, single-frequency GPS–BDS RTK positioning. GPS Solutions. 21 (3): pp. 1315-1330.