An improved carrier phase smoothing pseudorange algorithm with self-modeling of ionospheric delay variation

doi:10.11947/j.AGCS.2019.20180404

Abstract

Abstract: The traditional single-frequency carrier phase smoothing pseudo-range algorithm is prone to divergence and precision degradation due to the influence of ionospheric delay. However, the existing solutions have limited accuracy improvement or need external data support. In this paper, the regularity of ionospheric variation is studied and a regressive model is established. On this basis, a self-modelling algorithm for single-frequency carrier phase smoothing pseudorange with ionospheric delay variation is proposed. The algorithm uses the ionospheric delay information contained in the pseudo-range and carrier observations to model the ionospheric delay, and deducts the ionospheric delay variation between epochs from the smooth pseudo-range, thus effectively avoiding the divergence of the smooth pseudo-range. Carrier smoothing pseudo-range algorithm of ionospheric self-modeling is realized by using GNSSer software. Static and dynamic observation data are used to carry out positioning experiment and precision analysis. The example shows that:① the long period regular Hatch filtering is seriously affected by the ionosphere; ② the precision of the self-modelling ionospheric delay can reach centimeter level, and the linear moving window fitting method is the best in the 30-minute window; ③ self-modeling ionospheric correction can effectively eliminate the influence of smooth pseudo-range ionosphere. With the increase of time window, the precision does not decrease; ④ the proposed algorithm is used for epoch-by-epoch single-frequency smoothing pseudo-range single-point positioning, and the positioning accuracy reaches sub-decimeter level in both static and dynamic NEU directions. In the dynamic positioning test, the horizontal and elevation direction accuracy is 6.25 cm and 10.4 cm, which are 5.4 times and 3.3 times higher than the original pseudo-range respectively.

Key words: ionospheric delay variation, Hatch filter, self-modeling, carrier phase smoothing pseudorange, single frequency

CLC Number:

P228

CHEN Zhengsheng, ZHANG Qinghua, LI Linyang, LI Xuerui, Lü Hao. An improved carrier phase smoothing pseudorange algorithm with self-modeling of ionospheric delay variation[J]. Acta Geodaetica et Cartographica Sinica, 2019, 48(9): 1107-1118.

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