标题:Multi-GNSS precise orbit positioning for airborne gravimetry over Antarctica
作者:Li, Min; Xu, Tianhe; Lu, Biao; He, Kaifei
作者机构:[Li, Min; Lu, Biao] German Res Ctr Geosci GFZ, D-14473 Potsdam, Germany.; [Li, Min; Lu, Biao] Tech Univ Berlin, TU Berlin, D-10623 Berlin, Germany.; 更多
通讯作者:Xu, Tianhe;Xu, TH;Xu, TH
通讯作者地址:[Xu, TH]Shandong Univ, Inst Space Sci, Weihai 264209, Peoples R China;[Xu, TH]State Key Lab Geoinformat Engn, Xian 710054, Shaanxi, Peoples R China.
来源:GPS SOLUTIONS
出版年:2019
卷:23
期:2
DOI:10.1007/s10291-019-0848-9
关键词:PPP; Double-difference; Position; Velocity; Clock offsets and drifts;; Airborne gravimetry; Antarctica
摘要:Accurate position, velocity, and acceleration information are critical for airborne gravimetry. In Antarctica, there is a sparse distribution of IGS stations, and the rough terrain makes it impractical to set up nearby reference stations. Therefore, traditional differential GPS techniques may be difficult to implement. Precise point positioning (PPP) is independent of reference stations and provides an unlimited operating distance. However, it is highly dependent on precise satellite orbit and clock information, and may be vulnerable to discontinuities of orbit or clock offsets. An extended PPP method, called precise orbit positioning (POP), is implemented towards multi-GNSS. This approach introduces a widely spaced network of stations and is independent of precise clock information, as it estimates satellite clock offsets and drifts on-the-fly and only relies on precise orbit information. The advantage of being independent of clock information is that the IGS ultra-rapid (predicted) products can be applied to real-time POP since the orbits can achieve an accuracy of about 5cm. This becomes significant when applied to airborne gravimetry, as gravity results calculated from gravity measurements and GNSS solutions can be investigated in real time. By means of processing of 5 IGS stations over Antarctica, it turns out that the PPP solution is greatly affected by discontinuities of the IGS orbit and clock offsets at the day boundaries, accompanied with some biases as large as several decimeters in the vertical component. However, the POP solution remains robust and almost no large positioning errors appear, and the accuracy improves by about 50% in the north, east, and up coordinate components. The aircraft positions derived from relative positioning, PPP, and POP during the kinematic flight period generally agree at the decimeter level because of the lack of observed satellites with elevation angles higher than 60 degrees. Nevertheless, the potential for POP to generate centimeter-level kinematic vertical positions over long baselines is illustrated. Moreover, the POP and double-difference derived velocities and accelerations agree with each other well in both static and kinematic flight periods. After a low-pass filter, the GNSS-based accelerations are of the order of 1 mgal and are considered useful for separating the disturbing kinematic accelerations from the gravity measurements.
收录类别:EI;SCOPUS;SCIE
资源类型:期刊论文
原文链接:https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063138391&doi=10.1007%2fs10291-019-0848-9&partnerID=40&md5=2c9177cdeceb3f4737bceac1ba22402e
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