Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8131644 | Advances in Space Research | 2018 | 30 Pages |
Abstract
Rapid initialization with ambiguity fixed resolution plays a key role in real-time Global Navigation Satellite Systems (GNSS) displacement monitoring of bridges. In this study, we propose a rapid initialization method with triple-frequency (TF) BeiDou Navigation Satellite System (BDS) and Global Positioning System (GPS) observations. The key step of this method is to form extra-wide-lane (EWL) ambiguity with TF BDS and GPS carrier-phase to reduce the ambiguity search space. In order to improve the speed of ambiguity resolution (AR) further, the strategies of fixing ambiguities in groups sequentially from long wavelength to the short and partial AR (PAR) with elevation and signal-to-noise ratio (SNR) criterions were proposed. Based on the real monitoring data on the Baishazhou Yangtze River Bridge, the AR efficiency was tested. The results illustrate that over 90% EWL ambiguities can be fixed by only single-epoch with TF BDSâ¯+â¯GPS. After EWL ambiguity is fixed, the wide-lane (WL) ambiguity success rate could improve from 20% with dual-frequency (DF) BDSâ¯+â¯GPS data to 70% with TF BDSâ¯+â¯GPS data, 50-80% and 80-90% for the three stations respectively. Since the area of ambiguity search space is reduced by TF observations, the ambiguity search time decrased significantly compared with the DF BDSâ¯+â¯GPS. In the Time-to-first-fix (TTFF) test, over 85% of epochs can complete the initialization process by only one epoch with one hour of 10â¯Hz TF BDSâ¯+â¯GPS data. However, DF BDSâ¯+â¯GPS has only 25%. As for the initialization time longer than two epochs, the counts of TTFFs of TF BDSâ¯+â¯GPS are significantly less than that of DF BDSâ¯+â¯GPS. Meanwhile, the integrated BDS and GPS can further enhance the geometry of satellites, which will be better for the precision improvement than the increase of signal frequencies.
Keywords
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Space and Planetary Science
Authors
Ruijie Xi, Weiping Jiang, Xiaolin Meng, Xiaohui Zhou, Qiyi He,