Investigation of Different Interpolation Models Used in Network-RTK for the Virtual Reference Station Technique

2011 ◽  
Vol 10 (2) ◽  
pp. 136-148 ◽  
Author(s):  
A. Al-Shaery ◽  
S. Lim ◽  
C. Rizos
Keyword(s):  
Reference Station ◽  
Virtual Reference ◽  
Network Rtk

The Compact Network RTK Method: An Effective Solution to Reduce GNSS Temporal and Spatial Decorrelation Error

2010 ◽  
Vol 63 (2) ◽  
pp. 343-362 ◽  
Author(s):  
Byungwoon Park ◽  
Changdon Kee
Keyword(s):  
Service Providers ◽  
Reference Station ◽  
Effective Solution ◽  
Data Link ◽  
Virtual Reference ◽  
Network Rtk ◽  
System A ◽  
Exchange Format ◽  
Vertical Error ◽  
Temporal And Spatial

This paper proposes a method that combines compact real-time kinematic (RTK) and reference station (RS) networking techniques, and shows that this approach can reduce both the temporal and spatial decorrelation error. The compact RTK method compatibility with all the conventional network RTK systems, i.e., Master-Auxiliary Concept (MAC), Virtual Reference Stations (VRS), and Flächen-Korrektur Parameter (FKP), is examined theoretically in this paper. To prove that the compact RTK approach is not only valid, but also helpful to the network RTK system, a field test was held using one hour of Receiver Independent Exchange Format (RINEX) data logged every second from Continuously Operating Reference Stations (CORS). No matter which network RTK method is applied, the Compact Network RTK approach resolves the ambiguity of the carrier phase in 10–40 s and determines position with 6–7 cm horizontal and 7–8 cm vertical error (95%) in a 100 by 100 km region. Moreover, the Compact Network RTK approach enables network RTK service providers to reduce the data-link bandwidth for correction messages to 5–700 bps (bit/s) down from several thousand bps, currently 9600 bps of GPRS/GSM, without a severe degradation of accuracy.

Algorithm for VRS Based on Star Structure

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.

scholarly journals HEIGHT DETERMINATION TECHNIQUES FOR THE NEXT NATIONAL HEIGHT SYSTEM OF FINLAND - A CASE STUDY

2015 ◽  
Vol 41 (4) ◽  
pp. 145-155
Author(s):  
Timo Saari ◽  
Markku Poutanen ◽  
Veikko Saaranen ◽  
Harri Kaartinen ◽  
Antero Kukko ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Pilot Project ◽  
Satellite System ◽  
Reference Station ◽  
Virtual Reference ◽  
Precise Levelling ◽  
Height Determination ◽  
Weak Points ◽  
Global Navigation Satellite

Precise levelling is known for its accuracy and reliability in height determination, but the process itself is slow, laborious and expensive. We have started a project to study methods for height determination that could decrease the creation time of national height systems without losing the accuracy and reliability that is needed for them. In the pilot project described here, we study some of the alternative techniques with a pilot field test where we compared them with the precise levelling. The purpose of the test is not to evaluate the mutual superiority or suitability of the techniques, but to establish the background for a larger test and to find strong and weak points of each technique. The techniques chosen for this study were precise levelling, Mobile Laser Scanning (MLS) and Global Navigation Satellite System (GNSS) levelling, which included static Global Positioning System (GPS) and Virtual Reference Station (VRS) measurements. This research highlighted the differences of the studied techniques and gave insights about the framework and procedure for the later experiments. The research will continue in a larger scale, where the suitability of the techniques regarding the height systems is to be determined.

scholarly journals Investigation of accurate method in 3-D position using Cors-Net in Istanbul

2012 ◽  
Vol 18 (2) ◽  
pp. 171-184 ◽  
Author(s):  
Kutalmis Gumus ◽  
Cahit Tagi Celik ◽  
Halil Erkaya
Keyword(s):  
Real Time ◽  
Conventional Method ◽  
Global Positioning System ◽  
Complex Structure ◽  
Accurate Method ◽  
Reference Station ◽  
Positioning System ◽  
Virtual Reference ◽  
Global Positioning ◽  
Set Up

In this study, for Istanbul, there are two Cors Networks (Cors-TR, Iski Cors) providing Virtual Reference Station (VRS), and Flachen Korrektur Parameter (FKP), corrections to rover receiver for determining 3-D positions in real time by Global Positioning System (GPS). To determine which method (or technique) provides accurate method for position fixing, a test network consisting of 49 stations was set up in Yildiz Technical University Davudpasa Campus. The coordinates of the stations in the test network were determined by conventional geodetic, classical RTK, VRS and FKP methods serviced by both Cors-TR and Iski Cors. The results were compared to the coordinates by the conventional method by using total station. The results showed a complex structure as the accuracy differs from one component to another such as in horizontal coordinates, Y components by CorsTR_VRS and Cors_TR_ FKP showed 'best' results while the same technique provided X components consistent accuracy with the Y component but less accurate than by real time kinematic (RTK). In vertical components, of all the techniques used for the h components, CorsTR_VRS showed 'best' accuracy with three outliers.

scholarly journals A Fixed Algorithm of Ambiguity among the Network RTK Reference Stations

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 165
Author(s):  
Shouhua Wang ◽  
Zhiqi You ◽  
Xiyan Sun
Keyword(s):  
Satellite Observation ◽  
Reference Station ◽  
Floating Point ◽  
Extended Kalman Filtering ◽  
Fixation Rate ◽  
Multiple Systems ◽  
Network Rtk ◽  
R Ratio ◽  
Point Solution ◽  
Ambiguity Decorrelation

In the face of a complex observation environment, the solution of the reference station of the ambiguity of network real-time kinematic (RTK) will be affected. The joint solution of multiple systems makes the ambiguity dimension increase steeply, which makes it difficult to estimate all the ambiguity. In addition, when receiving satellite observation signals in the environment with many occlusions, the received satellite observation values are prone to gross errors, resulting in obvious deviations in the solution. In this paper, a new network RTK fixation algorithm for partial ambiguity among the reference stations is proposed. It first estimates the floating-point ambiguity using the robust extended Kalman filtering (EKF) technique based on mean estimation, then finds the optimal ambiguity subset by the optimized partial ambiguity solving method. Finally, fixing the floating-point solution by the least-squares ambiguity decorrelation adjustment (LAMBDA) algorithm and the joint test of ratio (R-ratio) and bootstrapping success rate index solver. The experimental results indicate that the new method can significantly improve the fixation rate of ambiguity among network RTK reference stations and thus effectively improve the reliability of positioning results.

scholarly journals Improving the Stochastic Model for VRS Network-Based GNSS Surveying

2019 ◽  
Vol 54 (1) ◽  
pp. 17-30 ◽  
Author(s):  
Thanate Jongrujinan ◽  
Chalermchon Satirapod
Keyword(s):  
Stochastic Model ◽  
Covariance Matrix ◽  
Ambiguity Resolution ◽  
Reference Station ◽  
Double Difference ◽  
Atmospheric Effects ◽  
Equal Weight ◽  
Virtual Reference ◽  
Positioning Accuracy ◽  
Variance Covariance Matrix

Abstract The VRS network-based technique has become the main precise GNSS surveying method especially for medium-range baselines (approximately 20-70 km). The key concept of this approach is to use the observables of multiple reference stations to generate the network correction in the form of a virtual reference station for mitigating distance-dependent errors including atmospheric effects and orbital uncertainty at the user’s location. Numerous GNSS data processing strategies have been adopted in the functional model in order to improve both the positioning accuracy and the success of ambiguity resolution. However, it is impossible to completely model the aforementioned errors. As a result, the unmodelled residuals still remain in the virtual reference station observables when the least squares estimation is employed. An alternative approach to deal with these residuals is to construct a more realistic stochastic model whereby the variance-covariance matrix is assumed to be homoscedastic. This research aims to investigate a suitable stochastic model used for the VRS technique. The rigorous statistical method, MINQUE has been applied to estimate the variance-covariance matrix of the double-difference observables for a virtual reference station to rover baseline determination. The findings of the comparison to the equal-weight model and the satellite elevation-based model indicated that the MINQUE procedure could enhance the positioning accuracy. In addition, the reliability of ambiguity resolution is also improved.

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