Abstract
Reliable real-time kinematic (RTK) is crucially important for emerging global navigation satellite systems (GNSSs) applications, such as drones and unmanned vehicles. The performance of conventional single baseline RTK (SBRTK) with one reference station degrades greatly in dense, urban environments, due to signal blockage and multipath error. The increasing use of multiple reference stations for kinematic positioning can improve RTK positioning accuracy and availability in urban areas. This paper proposes a new algorithm for multi-baseline RTK (MBRTK) positioning based on the equivalence principle. The advantages of the solution are to keep observation independent and increase the redundancy to estimate the unknown parameters. The equivalent double-differenced (DD) observation equations for multiple reference stations are firstly developed through the equivalent transform. A modified Kalman filter with parameter constraints is proposed, as well as a partial ambiguity resolution (PAR) strategy is developed to determine an ambiguity subset. Finally, the static and kinematic experiments are carried out to validate the proposed algorithm. The results demonstrate that, compared with single global positioning system (GPS) and Beidou navigation system (BDS) RTK positioning, the GPS/BDS positioning for MBRTK can enhance the positioning accuracy with improvement by approximately (45%, 35%, and 27%) and (12%, 6%, and 19%) in the North (N), East (E), and Up (U) components, as well as the availability with improvement by about 33% and 10%, respectively. Moreover, the MBRTK model with two and three reference receivers can significantly increase the redundancy and provide smaller ambiguity dilution of precision (ADOP) values. Compared with the scheme-one and scheme-two for SBRTK, the MBRTK with multiple reference receivers have a positioning accuracy improvement by about (9%, 0%, and 6%) and (9%, 16%, and 16%) in N, E, and U components, as well as the availability improvement by approximately 10%. Therefore, compared with the conventional SBRTK, the MBRTK can enhance the strength of the kinematic positioning model as well as improve the positioning accuracy and availability.
Highlights
Global Navigation Satellite Systems (GNSSs) have been extensively used for scientific and commercial applications in geodesy, geodynamics, transportation, and other industries [1,2,3,4,5]
The redundancy is given based on the following assumptions, as (1) the ambiguities are estimated as time-continuous values, (2) the equivalent DD observation equations can be established in intra-system for both single global positioning system (GPS) and single Beidou navigation system (BDS), (3) multiple reference receivers can track the same satellites simultaneously
We present a new algorithm of multi-baseline RTK (MBRTK) based on the equivalence principle for precise kinematic positioning
Summary
Global Navigation Satellite Systems (GNSSs) have been extensively used for scientific and commercial applications in geodesy, geodynamics, transportation, and other industries [1,2,3,4,5]. The mostly investigated method is the increasing use of observations including multiple satellite systems and reference or rover receivers [11,12,13]. Shen and Li [33] developed the simplified equivalent equations in the case of each receiver tracking different satellites with elevation-dependent weights, whose computation efficiency was significantly improved comparing to that of the SBS. To address the aforementioned problems, a rigorous algorithm for MBRTK is presented in this paper to improve the RTK positioning accuracy and availability using multiple reference receivers, and a modified Kalman filter with parameter constraints is used to estimate the system states. In order to validate and assess the performance of the proposed method, the positioning results of different satellite systems and reference stations are calculated and compared with the SBRTK.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
