Abstract
ABSTRACT Precise point positioning with ambiguity resolution (PPP-AR) is a powerful tool for geodetic and time-constrained applications that require high precision. The performance of PPP-AR highly depends on the reliability of the correct integer carrier-phase ambiguity estimation. In this study, the performance of narrow-lane ambiguity resolution of PPP using the Least-squares AMBiguity Decorrelation (LAMBDA) and bootstrapping methods is extensively investigated using real data from 55 IGS stations over one-month in 2020. Static PPP with 24-, 12-, 8-, 4-, 2-, 1- and ½-h sessions using two different cutoff angles (7° and 30°) was conducted with three PPP modes: i.e. ambiguity-float and two kinds of ambiguity-fixed PPP using the LAMBDA and bootstrapping methods for narrow-lane AR, respectively. The results show that the LAMBDA method can produce more reliable results for 2 hour and shorter observation sessions compared with the bootstrapping method using a 7° cutoff angle. For a 30° cutoff angle, the LAMBDA method outperforms the bootstrapping method for observation sessions of 4 h and less. For long observation times, the bootstrapping method produced much more accurate coordinates compared with the LAMBDA method without considering the wrong fixes cases. The results also show that occurrences of fixing the wrong integer ambiguities using the bootstrapping method are higher than that of the LAMBDA method.
Highlights
Precise point positioning (PPP) has been increasingly used in many geoscience applications, thanks to its powerful and cost-effective technique (Li et al 2015; Labib et al 2019)
In order to investigate the performance of NL ambiguity resolution (AR) using the boot strapping and Least-squares AMBiguity Decorrelation (LAMBDA) methods, accuracy improve ments in north, east and up components from the two AR modes with respect to the float PPP solutions are given in Figures 3 and 4 for each observation session and cutoff angle
The results show that the bootstrapping method pro duces much more accurate results for observation sessions longer than 2 h, while the LAMBDA method performs much better than bootstrapping for observa tion sessions equal to and shorter than 2 h for the 7° cutoff angle
Summary
Precise point positioning (PPP) has been increasingly used in many geoscience applications, thanks to its powerful and cost-effective technique (Li et al 2015; Labib et al 2019). Teunissen, Joosten, and Tiberius (2003) investigate LAMBDA, TCAR (ThreeCarrier Ambiguity Resolution), and CIR (Cascading Integer Resolution) techniques for relative positioning. Wuhan AC have been producing phase/clock bias products using the integer clock model (Laurichesse et al 2009) which is consis tent with CODE (Centre for Orbit Determination in Europe) final orbit. In this study, these phase/clock bias products were used for PPP-AR. The performance of bootstrapping and LAMBDA methods on PPP narrow-lane (NL) AR was investigated using PRIDE PPP-AR software, while con sidering different observation length and satellite geome try scenes.
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