A Improving Method for Validating Ambiguity Resolution of BeiDou Static Baseline Solution with Medium-Long Baseline

2016 ◽  
pp. 591-601
Author(s):  
Junjun Ying ◽  
Chuanzhen Sheng ◽  
Jingkui Zhang
Keyword(s):  
Ambiguity Resolution ◽  
Long Baseline ◽  
Baseline Solution

scholarly journals A Robust Strategy for Ambiguity Resolution Using Un-Differenced and Un-Combined GNSS Models in Network RTK

2015 ◽  
Vol 69 (3) ◽  
pp. 504-520
Author(s):  
Denghui Wang ◽  
Chengfa Gao ◽  
Shuguo Pan ◽  
Yang Yang
Keyword(s):  
Global Positioning System ◽  
Ambiguity Resolution ◽  
Plate Boundary ◽  
Double Difference ◽  
Fixed Rate ◽  
Long Baseline ◽  
Global Positioning ◽  
Baseline Solution ◽  
Integrated Processing ◽  
Gps Networks

An increasing number of reference stations have been established, leading to a sharp increase in the workload of Double-Difference (DD) baseline solutions, which are not appropriate for the integrated processing of denser networks. Correlations among the ambiguities in DD models are complex, and it is difficult to get precise solutions. This paper improves the DD ambiguity resolution performance over a long baseline, using a modified strategy based on an Un-Differenced (UD) and Un-Combined (UC) model. The satellite clocks are estimated as parameters, which are properly constrained by real-time satellite clock products for improving the smoothness of ambiguities. We use data from the Earth Scope Plate Boundary Observatory to examine the presented method in Global Positioning System (GPS) networks. Our method obtained more obviously centralised distributions. The successful fixed rate was 96·4% for the DD baseline solution, and 98·4% for the UD method. The proposed strategy is appropriate for the distributed architecture of extensive systems and avoids a heavy computational burden.

An Improved Geometry-free Three Carrier Ambiguity Resolution Method for the BeiDou Navigation Satellite System

2016 ◽  
Vol 69 (6) ◽  
pp. 1393-1408 ◽  
Author(s):  
Xing Wang ◽  
Wenxiang Liu ◽  
Guangfu Sun
Keyword(s):  
Ambiguity Resolution ◽  
Carrier Phase ◽  
Success Probability ◽  
Satellite System ◽  
Observation Data ◽  
Short Baseline ◽  
Long Baseline ◽  
Triple Frequency ◽  
Wide Lane ◽  
Three Carrier Ambiguity Resolution

BeiDou satellites transmit triple-frequency signals, which bring substantial benefits to carrier phase Ambiguity Resolution (AR). The traditional geometry-free model Three-Carrier Ambiguity Resolution (TCAR) method looks for a suitable combination of carrier phase and code-range observables by searching and comparing in the integer range, which limits the AR success probability. By analysing the error characteristics of the BeiDou triple-frequency observables, we introduce a new procedure to select the optimal combination of carrier phase and code observables to resolve the resolution of Extra-Wide-Lane (EWL) and Wide-Lane (WL) ambiguity. We also investigate a geometry-free and ionosphere-eliminated method for AR of the Medium-Lane (ML) and Narrow-Lane (NL) observables. In order to evaluate the performance of the improved TCAR method, real BeiDou triple-frequency observation data for different baseline cases were collected and processed epoch-by-epoch. The results show that the improved geometry-free TCAR method increases the single epoch AR success probability by up to 90% for short baseline and 80% for long baseline. The A perfect (100%) AR success probability can also be effortlessly achieved by averaging the float ambiguities over just tens of epochs.

Carrier Phase GPS Navigation to the North Pole

1999 ◽  
Vol 52 (1) ◽  
pp. 80-89 ◽  
Author(s):  
T. Moore ◽  
G. W. Roberts
Keyword(s):  
Ambiguity Resolution ◽  
Carrier Phase ◽  
Integer Ambiguity Resolution ◽  
North Pole ◽  
Integer Ambiguity ◽  
Reference Station ◽  
Baseline Length ◽  
Cycle Slips ◽  
The North ◽  
Long Baseline

Over the last few years, on-the-fly integer ambiguity resolution for GPS has proven to be successful over short baselines (<20 km). However, the remaining challenge has been to extend the length of the baseline between the reference station and the mobile receiver, whilst still maintaining the capability of on-the-fly resolution and true carrier-based kinematic positioning. The goal has been to achieve centimetric level positioning at ranges of over 500 km. New techniques have been developed at the University of Nottingham to allow very long baseline integer ambiguity resolution, on-the-fly. A major problem with the use of carrier phase data is that posed by cycle slips. A technique for detecting and correcting cycle slips has been developed, and its use is discussed in this paper. The new technique has been proven through a series of trials, one of which included two flights to the North Pole, performing centimetric level positioning all the way to the pole. For many years, the GD Aero-Systems Course of the Air Warfare Centre based at RAF Cranwell executed a series of equipment flight trials to the North Pole, called the ARIES Flights. In May 1996, the authors were fortunate to take part in both flights, via Iceland and Greenland, to the North Pole. Based on reference stations at Thule Air Base, integer ambiguity resolution was accomplished, on-the-fly, and centimetric level navigation maintained throughout the flights. Earlier trials detailed in the paper demonstrate that the technique can resolve integer ambiguities on-the-fly within a few seconds over a baseline length of approximately 134 km, resulting in an accuracy of 12 cm. The majority of the residual error source for this being the ionosphere.

scholarly journals GLONASS FDMA data for RTK positioning: a five-system analysis

GPS Solutions ◽  
2020 ◽  
Vol 25 (1) ◽  
Author(s):  
Andreas Brack ◽  
Benjamin Männel ◽  
Harald Schuh
Keyword(s):  
Ambiguity Resolution ◽  
System Analysis ◽  
Formal Analysis ◽  
Real Data ◽  
Strong Impact ◽  
Combined Model ◽  
Partial Ambiguity Resolution ◽  
Long Baseline ◽  
Weighted Model ◽  
Difference Test

Abstract The use of the GLONASS legacy signals for real-time kinematic positioning is considered. Due to the FDMA multiplexing scheme, the conventional CDMA observation model has to be modified to restore the integer estimability of the ambiguities. This modification has a strong impact on positioning capabilities. In particular, the ambiguity resolution performance of this model is clearly weaker than for CDMA systems, so that fast and reliable full ambiguity resolution is usually not feasible for standalone GLONASS, and adding GLONASS data in a multi-GNSS approach can reduce the ambiguity resolution performance of the combined model. Partial ambiguity resolution was demonstrated to be a suitable tool to overcome this weakness (Teunissen in GPS Solut 23(4):100, 2019). We provide an exhaustive formal analysis of the positioning precision and ambiguity resolution capabilities for short, medium, and long baselines in a multi-GNSS environment with GPS, Galileo, BeiDou, QZSS, and GLONASS. Simulations are used to show that with a difference test-based partial ambiguity resolution method, adding GLONASS data improves the positioning performance in all considered cases. Real data from different baselines are used to verify these findings. When using all five available systems, instantaneous centimeter-level positioning is possible on an 88.5 km baseline with the ionosphere weighted model, and on average, only 3.27 epochs are required for a long baseline with the ionosphere float model, thereby enabling near instantaneous solutions.

scholarly journals Predicting the Success Rate of Long-baseline GPS+Galileo (Partial) Ambiguity Resolution

2014 ◽  
Vol 67 (3) ◽  
pp. 385-401 ◽  
Author(s):  
Dennis Odijk ◽  
Balwinder S. Arora ◽  
Peter J.G. Teunissen
Keyword(s):  
Ambiguity Resolution ◽  
Satellite System ◽  
Observation Time ◽  
Baseline Length ◽  
Success Rates ◽  
Dual Frequency ◽  
Variance Matrix ◽  
Partial Ambiguity Resolution ◽  
Long Baseline ◽  
Triple Frequency

This contribution covers precise (cm-level) relative Global Navigation Satellite System (GNSS) positioning for which the baseline length can reach up to a few hundred km. Carrier-phase ambiguity resolution is required to obtain this high positioning accuracy within manageable observation time spans. However, for such long baselines, the differential ionospheric delays hamper fast ambiguity resolution as based on current dual-frequency Global Positioning System (GPS). It is expected that the modernization of GPS towards a triple-frequency system, as well as the development of Galileo towards a full constellation will be beneficial in speeding up long-baseline ambiguity resolution. In this article we will predict ambiguity resolution success rates for GPS+Galileo for a 250 km baseline based on the ambiguity variance matrix, where the Galileo constellation is simulated by means of Yuma almanac data. From our studies it can be concluded that ambiguity resolution will likely become faster (less than ten minutes) in the case of GPS+Galileo when based on triple-frequency data of both systems, however much shorter times to fix the ambiguities (one-two minutes) can be expected when only a subset of ambiguities is fixed instead of the complete vector (partial ambiguity resolution).

A New Strategy for GPS Triple-Frequency Long-Baseline Ambiguity Resolution

2020 ◽  
Vol 99 (sp1) ◽  
pp. 189
Author(s):  
Ji Liu ◽  
Chongmeng Zhang ◽  
Dongliang Shu
Keyword(s):  
Ambiguity Resolution ◽  
Long Baseline ◽  
Triple Frequency ◽  
New Strategy

scholarly journals A Long Baseline Three Carrier Ambiguity Resolution with a New Ionospheric Constraint

2016 ◽  
Vol 5 (11) ◽  
pp. 198 ◽  
Author(s):  
Yafei Ning ◽  
Yunbin Yuan ◽  
Zhen Huang ◽  
Yanju Chai ◽  
Bingfeng Tan
Keyword(s):  
Ambiguity Resolution ◽  
Long Baseline ◽  
Three Carrier Ambiguity Resolution
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