Performance Assessment of a Long Range Reference Station Ambiguity Resolution Algorithm for Network RTK GPS Positioning

The average inter-station distances in most established network Real Time Kinematic (RTK) systems are constrained to around 50 km. A sparse network RTK system with an average inter-station distance of up to 300 km would have many appealing advantages over a conventional one, including a significant reduction in the development and maintenance costs. The first part of this paper introduces the key approaches for sparse network RTK positioning technology. These include long-range reference baseline ambiguity resolution and real-time kinematic ambiguity resolution for the rover receivers. The proposed method for long-range kinematic ambiguity resolution can overcome the network weaknesses through three procedures: application of the interpolated corrections from the sparse network only to wide-lane combination; searching the ambiguities of wide-lane combination; and searching L1 ambiguities with wide-lane combination and ionosphere-free observables. To test these techniques, a network including ten reference stations was created from the Ordnance Survey's Network (OS NetTM) that covers the whole territory of the United Kingdom (UK). The average baseline length of this sparse network is about 300 km. To assess the positioning performance, nine rover stations situated inside and outside the network were also selected from the OS Net™. Finally, the accuracy of interpolated corrections, the positioning accuracy and the initialization time required for precise positioning were estimated and analysed. From the observed performance of each rover receiver, and the accuracy of interpolated network corrections, it can be concluded that it is feasible to use a sparse reference station network with an average inter-station distance up to 300 km for achieving similar performance to traditional network RTK positioning. The proposed approach can provide more cost-efficient use of network RTK (NRTK) positioning for engineering and environmental applications that are currently being delivered by traditional network RTK positioning technology.

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Fast ambiguity resolution for long-range reference station networks with ionospheric model constraint method

GPS Solutions ◽

10.1007/s10291-016-0551-z ◽

2016 ◽

Vol 21 (2) ◽

pp. 617-626 ◽

Cited By ~ 7

Author(s):

Ming Zhang ◽

Hui Liu ◽

Zhengdong Bai ◽

Chuang Qian ◽

Chengcheng Fan ◽

...

Keyword(s):

Long Range ◽

Ambiguity Resolution ◽

Reference Station ◽

Ionospheric Model ◽

Model Constraint ◽

Constraint Method

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An approach for instantaneous ambiguity resolution for medium- to long-range multiple reference station networks

GPS Solutions ◽

10.1007/s10291-004-0120-8 ◽

2004 ◽

Vol 9 (1) ◽

pp. 1-11 ◽

Cited By ~ 30

Author(s):

G. Hu ◽

D. A. Abbey ◽

N. Castleden ◽

W. E. Featherstone ◽

C. Earls ◽

...

Keyword(s):

Long Range ◽

Ambiguity Resolution ◽

Reference Station ◽

Multiple Reference

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Divisional ambiguity resolution for long range reference stations in network RTK

Survey Review ◽

10.1179/1752270614y.0000000123 ◽

2014 ◽

Vol 47 (343) ◽

pp. 272-278 ◽

Cited By ~ 3

Author(s):

J. Deng ◽

S. L. Wang

Keyword(s):

Long Range ◽

Ambiguity Resolution ◽

Network Rtk

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Algorithm for VRS Based on Star Structure

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.90-93.2828 ◽

2011 ◽

Vol 90-93 ◽

pp. 2828-2831

Author(s):

Cheng Fa Gao ◽

Xue Feng Shen

Keyword(s):

Ambiguity Resolution ◽

Solution Method ◽

Fixed Time ◽

Reference Station ◽

Virtual Reference ◽

Star Network ◽

Network Rtk ◽

Baseline Solution ◽

Triangular Network ◽

Star Structure

In view of the deficiency of algorithm for VRS (Virtual Reference Station) based on the triangular network, a novel algorithm for VRS which is based on star network is proposed. Firstly, a kind of baseline solution method of network RTK/VRS based on star structure is established and an ambiguity resolution method is also proposed in this paper. Then further research is done to analyze the algorithm of ionospheric and tropospheric correction separately. Finally, the network ambiguity resolution and correction calculation in both star structure network and traditional triangular network are verified and analyzed through two tests. These tests indicate that the Network RTK (VRS) based on star structure this paper proposed can obviously accelerate the fixed time of network ambiguity resolution, which can be up to 50%, and can achieve higher precision and reliability in the generation of network correction.

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Single-epoch RTK performance assessment of tightly combined BDS-2 and newly complete BDS-3

Satellite Navigation ◽

10.1186/s43020-021-00038-y ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Wanke Liu ◽

Mingkui Wu ◽

Xiaohong Zhang ◽

Wang Wang ◽

Wei Ke ◽

...

Keyword(s):

Performance Assessment ◽

Success Rate ◽

Ambiguity Resolution ◽

Satellite System ◽

Asia Pacific ◽

Single Frequency ◽

Navigation Satellite ◽

Short Baseline ◽

Positioning Accuracy ◽

Single Epoch

AbstractThe BeiDou global navigation satellite system (BDS-3) constellation deployment has been completed on June 23, 2020, with a full constellation comprising 30 satellites. In this study, we present the performance assessment of single-epoch Real-Time Kinematic (RTK) positioning with tightly combined BeiDou regional navigation satellite system (BDS-2) and BDS-3. We first investigate whether code and phase Differential Inter-System Biases (DISBs) exist between the legacy B1I/B3I signals of BDS-3/BDS-2. It is discovered that the DISBs are in fact about zero for the baselines with the same or different receiver types at their endpoints. These results imply that BDS-3 and BDS-2 are fully interoperable and can be regarded as one constellation without additional DISBs when the legacy B1I/B3I signals are used for precise relative positioning. Then we preliminarily evaluate the single-epoch short baseline RTK performance of tightly combined BDS-2 and the newly completed BDS-3. The performance is evaluated through ambiguity resolution success rate, ambiguity dilution of precision, as well as positioning accuracy in kinematic and static modes using the datasets collected in Wuhan. Experimental results demonstrate that the current BDS-3 only solutions can deliver comparable ambiguity resolution performance and much better positioning accuracy with respect to BDS-2 only solutions. Moreover, the RTK performance is much improved with tightly combined BDS-3/BDS-2, particularly in challenging or harsh conditions. The single-frequency single-epoch tightly combined BDS-3/BDS-2 solution could deliver an ambiguity resolution success rate of 96.9% even with an elevation cut-off angle of 40°, indicating that the tightly combined BDS-3/BDS-2 could achieve superior RTK positioning performance in the Asia–Pacific region. Meanwhile, the three-dimensional (East/North/Up) positioning accuracy of BDS-3 only solution (0.52 cm/0.39 cm/2.14 cm) in the kinematic test is significantly better than that of the BDS-2 only solution (0.85 cm/1.02 cm/3.01 cm) due to the better geometry of the current BDS-3 constellation. The tightly combined BDS-3/BDS-2 solution can provide the positioning accuracy of 0.52 cm, 0.22 cm, and 1.80 cm, respectively.

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