Rapid Estimation of Undifferenced Multi-GNSS Real-Time Satellite Clock Offset Using Partial Observations
Real-time satellite clock offset is a crucial element for real-time precise point positioning (RT-PPP). However, the elapsed time for undifferenced (UD) multi-global navigation satellite system (GNSS) real-time satellite clock offset estimation at each epoch is increased with the growth of stations,...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-03-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/15/7/1776 |
| _version_ | 1797607097317195776 |
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| author | Wei Xie Guanwen Huang Wenju Fu Shi Du Bobin Cui Mengyuan Li Yue Tan |
| author_facet | Wei Xie Guanwen Huang Wenju Fu Shi Du Bobin Cui Mengyuan Li Yue Tan |
| author_sort | Wei Xie |
| collection | DOAJ |
| description | Real-time satellite clock offset is a crucial element for real-time precise point positioning (RT-PPP). However, the elapsed time for undifferenced (UD) multi-global navigation satellite system (GNSS) real-time satellite clock offset estimation at each epoch is increased with the growth of stations, which may fall short of real-time application requirements. Therefore, a rapid estimation method for UD multi-GNSS real-time satellite clock offset is proposed to improve the computation efficiency, in which both the dimension of the normal equation (NEQ) and the number of redundant observations are calculated before adjustment; if these two values are larger than the predefined thresholds, the elevation mask is gradually increased until they are less than the predefined thresholds. Then, the clock offset estimation is conducted; this method is called clock offset estimation using partial observations. Totals of 50, 60, 70 and 80 stations are applied to perform experiments. Compared to clock offset estimation using all observations, the elapsed times of clock offset estimation using partial observations can be reduced from 6.80 to 3.10 s, 7.93 to 2.97 s, 12.04 to 3.14 s for 60, 70 and 80 stations, respectively. By using the proposed method, the elapsed time of the clock offset estimation at each epoch is less than 5 s. The estimated clock offset accuracy for GPS, BDS-3, Galileo and GLONASS satellites are better than 0.04, 0.05, 0.03 and 0.16 ns when using the partial observations to estimate clock offset with 50, 60, 70 and 80 stations, respectively. For the multi-GNSS kinematic PPP using the estimated clock offset from 50, 60, 70 and 80 stations with partial observations, the positioning accuracy at 95% confidence level in the east, north and up direction are better than 2.70, 2.20 and 5.60 cm, respectively. |
| first_indexed | 2024-03-11T05:25:30Z |
| format | Article |
| id | doaj.art-1bc0b5d4ba3a4885a35b19a845a3ed64 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-03-11T05:25:30Z |
| publishDate | 2023-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-1bc0b5d4ba3a4885a35b19a845a3ed642023-11-17T17:28:46ZengMDPI AGRemote Sensing2072-42922023-03-01157177610.3390/rs15071776Rapid Estimation of Undifferenced Multi-GNSS Real-Time Satellite Clock Offset Using Partial ObservationsWei Xie0Guanwen Huang1Wenju Fu2Shi Du3Bobin Cui4Mengyuan Li5Yue Tan6College of Geology Engineering and Geomatics, Chang’an University, Xi’an 710054, ChinaCollege of Geology Engineering and Geomatics, Chang’an University, Xi’an 710054, ChinaState Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, ChinaGerman Research Centre for Geosciences (GFZ), Telegrafenberg, 14473 Potsdam, GermanyGerman Research Centre for Geosciences (GFZ), Telegrafenberg, 14473 Potsdam, GermanyCollege of Geology Engineering and Geomatics, Chang’an University, Xi’an 710054, ChinaCollege of Geology Engineering and Geomatics, Chang’an University, Xi’an 710054, ChinaReal-time satellite clock offset is a crucial element for real-time precise point positioning (RT-PPP). However, the elapsed time for undifferenced (UD) multi-global navigation satellite system (GNSS) real-time satellite clock offset estimation at each epoch is increased with the growth of stations, which may fall short of real-time application requirements. Therefore, a rapid estimation method for UD multi-GNSS real-time satellite clock offset is proposed to improve the computation efficiency, in which both the dimension of the normal equation (NEQ) and the number of redundant observations are calculated before adjustment; if these two values are larger than the predefined thresholds, the elevation mask is gradually increased until they are less than the predefined thresholds. Then, the clock offset estimation is conducted; this method is called clock offset estimation using partial observations. Totals of 50, 60, 70 and 80 stations are applied to perform experiments. Compared to clock offset estimation using all observations, the elapsed times of clock offset estimation using partial observations can be reduced from 6.80 to 3.10 s, 7.93 to 2.97 s, 12.04 to 3.14 s for 60, 70 and 80 stations, respectively. By using the proposed method, the elapsed time of the clock offset estimation at each epoch is less than 5 s. The estimated clock offset accuracy for GPS, BDS-3, Galileo and GLONASS satellites are better than 0.04, 0.05, 0.03 and 0.16 ns when using the partial observations to estimate clock offset with 50, 60, 70 and 80 stations, respectively. For the multi-GNSS kinematic PPP using the estimated clock offset from 50, 60, 70 and 80 stations with partial observations, the positioning accuracy at 95% confidence level in the east, north and up direction are better than 2.70, 2.20 and 5.60 cm, respectively.https://www.mdpi.com/2072-4292/15/7/1776clock offset estimationrapid estimationmulti-GNSSpartial observationscomputational efficiency |
| spellingShingle | Wei Xie Guanwen Huang Wenju Fu Shi Du Bobin Cui Mengyuan Li Yue Tan Rapid Estimation of Undifferenced Multi-GNSS Real-Time Satellite Clock Offset Using Partial Observations Remote Sensing clock offset estimation rapid estimation multi-GNSS partial observations computational efficiency |
| title | Rapid Estimation of Undifferenced Multi-GNSS Real-Time Satellite Clock Offset Using Partial Observations |
| title_full | Rapid Estimation of Undifferenced Multi-GNSS Real-Time Satellite Clock Offset Using Partial Observations |
| title_fullStr | Rapid Estimation of Undifferenced Multi-GNSS Real-Time Satellite Clock Offset Using Partial Observations |
| title_full_unstemmed | Rapid Estimation of Undifferenced Multi-GNSS Real-Time Satellite Clock Offset Using Partial Observations |
| title_short | Rapid Estimation of Undifferenced Multi-GNSS Real-Time Satellite Clock Offset Using Partial Observations |
| title_sort | rapid estimation of undifferenced multi gnss real time satellite clock offset using partial observations |
| topic | clock offset estimation rapid estimation multi-GNSS partial observations computational efficiency |
| url | https://www.mdpi.com/2072-4292/15/7/1776 |
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