Performance Evaluation of GPS Single-Epoch On-the-Fly Ambiguity Resolution

Abstract

GPS applications that require precise phase solutions in difficult environments, where loss of lock is likely, would benefit from instantaneous (single-epoch) phase integer ambiguity resolution. Among these applications are aircraft positioning and attitude determination during a photogrammetric flight, engineering surveying, and large-scale mapping. This paper reviews current GPS on-the-fly (OTF) techniques; a single-epoch ambiguity resolution approach is discussed in detail. Test results from 48 h of static data and 105 min. of kinematic data are presented. Results are also provided to demonstrate the ability of the algorithm to determine the attitude of a platform. Comparison of the technique's performance with that of commercial software demonstrates subcentimeter precision results all of the time (100 percent success), provided that at least five satellites are available and multipath errors are small.

Satellite Positioning with Large Constellations

“…The traditional method used for carrier-phase positioning is to resolve integer ambiguities prior to estimating the baseline coordinates. Multiple methods have been developed along these lines, including the works of Teunissen [2] and Chang et al [3] (already mentioned above), Hatch [8], Remondi [9], Al-Haifi et al [10], and Hassibi and Boyd [11]. Recent interest in positioning with multiple satellite constellations has spurred the development of integer ambiguity resolution algorithms that scale more favorably with the number of satellites [12].…”

“…Comparing ( 9) with ( 6), we see that the vector E ŵ m | ỹ, G can be interpreted as an estimate of the integer ambiguities m. In fact, it is the minimum mean-squared error (MMSE) estimator of the ambiguities. We emphasize that this MMSE estimator takes the integer nature of the ambiguities into account, as can be seen from (10).…”

Spatially convergent GPS kinematic positioning

“…At the correct receiver position, all the fractional, single-differenced phase measurements should theoretically be in alignment, resulting in the maximum ambiguity function value (Han and Rizos 1996;Hofmann-Wellenhof et al 1997). The position search algorithm, based on the ambiguity function, is characterized by its insensitivity to cycle slips and by its ease-of-use in connection with multiple reference stations (Al-Haifi et al 1997). In this paper, we discuss an integer ambiguity elimination technique that employs a periodic cosine function.…”

A Bayesian Technique for Real and Integer Parameters Estimation in Linear Models and its Application to GNSS High Precision Positioning

“…Most of ambiguity resolution methods discussed in the literature are based in a coarse estimation followed by a refinement process to find the final estimate [5]. In the case of the Ambiguity Function Method, the possible integer values are restricted to a grid corresponding to a discretization of the position variables [6].…”