A New Strategy for GPS Triple-Frequency Long-Baseline Ambiguity Resolution

Ji Liu; Chongmeng Zhang; Dongliang Shu

doi:10.2112/si99-027.1

An Improved Geometry-free Three Carrier Ambiguity Resolution Method for the BeiDou Navigation Satellite System

Journal of Navigation ◽

10.1017/s0373463316000163 ◽

2016 ◽

Vol 69 (6) ◽

pp. 1393-1408 ◽

Cited By ~ 4

Author(s):

Xing Wang ◽

Wenxiang Liu ◽

Guangfu Sun

Keyword(s):

Ambiguity Resolution ◽

Carrier Phase ◽

Success Probability ◽

Satellite System ◽

Observation Data ◽

Short Baseline ◽

Long Baseline ◽

Triple Frequency ◽

Wide Lane ◽

Three Carrier Ambiguity Resolution

BeiDou satellites transmit triple-frequency signals, which bring substantial benefits to carrier phase Ambiguity Resolution (AR). The traditional geometry-free model Three-Carrier Ambiguity Resolution (TCAR) method looks for a suitable combination of carrier phase and code-range observables by searching and comparing in the integer range, which limits the AR success probability. By analysing the error characteristics of the BeiDou triple-frequency observables, we introduce a new procedure to select the optimal combination of carrier phase and code observables to resolve the resolution of Extra-Wide-Lane (EWL) and Wide-Lane (WL) ambiguity. We also investigate a geometry-free and ionosphere-eliminated method for AR of the Medium-Lane (ML) and Narrow-Lane (NL) observables. In order to evaluate the performance of the improved TCAR method, real BeiDou triple-frequency observation data for different baseline cases were collected and processed epoch-by-epoch. The results show that the improved geometry-free TCAR method increases the single epoch AR success probability by up to 90% for short baseline and 80% for long baseline. The A perfect (100%) AR success probability can also be effortlessly achieved by averaging the float ambiguities over just tens of epochs.

Download Full-text

Predicting the Success Rate of Long-baseline GPS+Galileo (Partial) Ambiguity Resolution

Journal of Navigation ◽

10.1017/s037346331400006x ◽

2014 ◽

Vol 67 (3) ◽

pp. 385-401 ◽

Cited By ~ 22

Author(s):

Dennis Odijk ◽

Balwinder S. Arora ◽

Peter J.G. Teunissen

Keyword(s):

Ambiguity Resolution ◽

Satellite System ◽

Observation Time ◽

Baseline Length ◽

Success Rates ◽

Dual Frequency ◽

Variance Matrix ◽

Partial Ambiguity Resolution ◽

Long Baseline ◽

Triple Frequency

This contribution covers precise (cm-level) relative Global Navigation Satellite System (GNSS) positioning for which the baseline length can reach up to a few hundred km. Carrier-phase ambiguity resolution is required to obtain this high positioning accuracy within manageable observation time spans. However, for such long baselines, the differential ionospheric delays hamper fast ambiguity resolution as based on current dual-frequency Global Positioning System (GPS). It is expected that the modernization of GPS towards a triple-frequency system, as well as the development of Galileo towards a full constellation will be beneficial in speeding up long-baseline ambiguity resolution. In this article we will predict ambiguity resolution success rates for GPS+Galileo for a 250 km baseline based on the ambiguity variance matrix, where the Galileo constellation is simulated by means of Yuma almanac data. From our studies it can be concluded that ambiguity resolution will likely become faster (less than ten minutes) in the case of GPS+Galileo when based on triple-frequency data of both systems, however much shorter times to fix the ambiguities (one-two minutes) can be expected when only a subset of ambiguities is fixed instead of the complete vector (partial ambiguity resolution).

Download Full-text