Springer Nature;Berlin/Heidelberg: Springer Science and Business Media LLC
摘要:
摘要： Differential ionospheric slant delays are obtained from a quiet-time, three-dimensional ionospheric electron density model, called the TaiWan Ionosphere Model (TWIM), to be used in code-based differential GPS positioning. The code observations are acquired from nine continuously operating GPS stations around Taiwan whose baseline ranged from 19 to 340 km. Daily 24-hour epoch-per-epoch positioning obtained for 70 most geomagnetic quiet days (2008–2010) for each of the 72 baselines. The performance of TWIM has been compared with the standard operational Klobuchar model (KLB) used by typical single-frequency receivers and the IGS global ionospheric model (GIM). Generally, TWIM performed well in reducing the differential ionospheric delay especially for long baselines and different levels of low solar activity. It has a much better performance compared to the operational KLB model. TWIM also performed similarly with GIM, though GIM has the best performance overall. GIM has the best ionospheric gradient estimates among the three models whose differential ionospheric delay-to-horizontal error ratio is more than 0.25. This is followed closely by TWIM with about 0.20. KLB only has a ratio of <0.10. The similarity of the performance of TWIM and GIM demonstrates the feasibility of TWIM in correcting for differential ionospheric delays in the C/A code pseudorange that is caused by electron density gradients in the ionosphere. It can provide decimeter-to-centimeter level accuracy in differential GPS positioning for single-frequency receivers during geomagnetic quiet conditions across all seasons and different levels of low solar activities. 其他題名： GPS Solut 出版者： Berlin/Heidelberg: Springer Science and Business Media LLC 出版日期： 2016-04-01 出處： GPS Solutions, 2016-04, Vol.20 (2), p.173-185 資源來源： SpringerLink Journals Online. 版權： Springer-Verlag Berlin Heidelberg 2014 版權： GPS Solutions is a copyright of Springer, (2014). All Rights Reserved. 識別號： ISSN: 1080-5370 識別號： EISSN: 1521-1886 識別號： DOI: 10.1007/s10291-014-0422-4
