Investigation and Validation of the Time-Varying Characteristic for the GPS Differential Code Bias
The time-varying characteristic of the bias in the GPS code observation is investigated using triple-frequency observations. The method for estimating the combined code bias is presented and the twelve-month (1 January⁻31 December 2016) triple-frequency GPS data set from 114 International...
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| Format: | Article |
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MDPI AG
2019-02-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/11/4/428 |
| _version_ | 1819294816374095872 |
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| author | Haojun Li Jingxin Xiao Weidong Zhu |
| author_facet | Haojun Li Jingxin Xiao Weidong Zhu |
| author_sort | Haojun Li |
| collection | DOAJ |
| description | The time-varying characteristic of the bias in the GPS code observation is investigated using triple-frequency observations. The method for estimating the combined code bias is presented and the twelve-month (1 January⁻31 December 2016) triple-frequency GPS data set from 114 International GNSS Service (IGS) stations is processed to analyze the characteristic of the combined code bias. The results show that the main periods of the combined code bias are 12, 8, 6, 4, 4.8 and 2.67 h. The time-varying characteristic of the combined code bias, which is the combination of differential code bias (DCB) (P1⁻P5) and DCB (P1⁻P2), shows that the real satellite DCBs are also time-varying. The difference between the two sets of the computed constant parts of the combined code bias, with the IGS DCB products of DCB (P1⁻P2) and DCB (P1⁻P2) and the mean of the estimated 24-h combined code bias series, further show that the combined code bias cannot be replaced by the DCB (P1⁻P2) and DCB (P1⁻P5) products. The time-varying part of inter-frequency clock bias (IFCB) can be estimated by the phase and code observations and the phase based IFCB is the combinations of the triple-frequency satellite uncalibrated phase delays (UPDs) and the code-based IFCB is the function of the DCBs. The performances of the computed the IFCB with different methods in single point positioning indicate that the accuracy for the constant part of the combined code bias is reduced, when the IGS DCB products are used to compute. These performances also show that the time-varying part of IFCB estimated with phase observation is better than that of code observation. The predicted results show that 98% of the predicted constant part of the combined code bias can be corrected and the attenuation of the predicted accuracy is much less evident. However, the accuracy of the predicted time-varying part decreases significantly with the predicted time. |
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| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-12-24T04:32:20Z |
| publishDate | 2019-02-01 |
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| series | Remote Sensing |
| spelling | doaj.art-de079e80b48e49aa8c6c7c43d49ea76e2022-12-21T17:15:22ZengMDPI AGRemote Sensing2072-42922019-02-0111442810.3390/rs11040428rs11040428Investigation and Validation of the Time-Varying Characteristic for the GPS Differential Code BiasHaojun Li0Jingxin Xiao1Weidong Zhu2College of Surveying and Geo-Informatics, Tongji University, Shanghai 200092, ChinaCollege of Surveying and Geo-Informatics, Tongji University, Shanghai 200092, ChinaCollege of Marine Sciences, Shanghai Ocean University, Shanghai 201306, ChinaThe time-varying characteristic of the bias in the GPS code observation is investigated using triple-frequency observations. The method for estimating the combined code bias is presented and the twelve-month (1 January⁻31 December 2016) triple-frequency GPS data set from 114 International GNSS Service (IGS) stations is processed to analyze the characteristic of the combined code bias. The results show that the main periods of the combined code bias are 12, 8, 6, 4, 4.8 and 2.67 h. The time-varying characteristic of the combined code bias, which is the combination of differential code bias (DCB) (P1⁻P5) and DCB (P1⁻P2), shows that the real satellite DCBs are also time-varying. The difference between the two sets of the computed constant parts of the combined code bias, with the IGS DCB products of DCB (P1⁻P2) and DCB (P1⁻P2) and the mean of the estimated 24-h combined code bias series, further show that the combined code bias cannot be replaced by the DCB (P1⁻P2) and DCB (P1⁻P5) products. The time-varying part of inter-frequency clock bias (IFCB) can be estimated by the phase and code observations and the phase based IFCB is the combinations of the triple-frequency satellite uncalibrated phase delays (UPDs) and the code-based IFCB is the function of the DCBs. The performances of the computed the IFCB with different methods in single point positioning indicate that the accuracy for the constant part of the combined code bias is reduced, when the IGS DCB products are used to compute. These performances also show that the time-varying part of IFCB estimated with phase observation is better than that of code observation. The predicted results show that 98% of the predicted constant part of the combined code bias can be corrected and the attenuation of the predicted accuracy is much less evident. However, the accuracy of the predicted time-varying part decreases significantly with the predicted time.https://www.mdpi.com/2072-4292/11/4/428hardware delay biasuncalibrated phase delayGPS satellite clockprecise point positioninginter-frequency clock bias |
| spellingShingle | Haojun Li Jingxin Xiao Weidong Zhu Investigation and Validation of the Time-Varying Characteristic for the GPS Differential Code Bias Remote Sensing hardware delay bias uncalibrated phase delay GPS satellite clock precise point positioning inter-frequency clock bias |
| title | Investigation and Validation of the Time-Varying Characteristic for the GPS Differential Code Bias |
| title_full | Investigation and Validation of the Time-Varying Characteristic for the GPS Differential Code Bias |
| title_fullStr | Investigation and Validation of the Time-Varying Characteristic for the GPS Differential Code Bias |
| title_full_unstemmed | Investigation and Validation of the Time-Varying Characteristic for the GPS Differential Code Bias |
| title_short | Investigation and Validation of the Time-Varying Characteristic for the GPS Differential Code Bias |
| title_sort | investigation and validation of the time varying characteristic for the gps differential code bias |
| topic | hardware delay bias uncalibrated phase delay GPS satellite clock precise point positioning inter-frequency clock bias |
| url | https://www.mdpi.com/2072-4292/11/4/428 |
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