ARIADNE with Ambiguity Resolution: Visual Marker Based Rapid Initialization of PPP-AR

摘要

Precise Point Positioning (PPP) offers advantages over Real-Time Kinematic (RTK) positioning in that it needs no ground base station or a rover to provide a communication channel with the base station. Therefore, PPP is expected to be applied in various fields, such as precise agriculture, intelligent transportation, construction, and mining. One major drawback of PPP is that it takes several tens of minutes for initial convergence to reach an adequate level of accuracy, and how to shorten the convergence time remains the key issue regarding the proliferation of PPP. In our previous work, we proposed a method of drastically reducing this initial convergence time of PPP (called "ARIADNE") by using an accurate fiducial marker whose position in Earth-fixed coordinates has been accurately measured using an onboard camera. In this contribution, in order to improve both the positioning accuracy and reliability, we introduce some new techniques to ARIADNE: (1) carrier phase ambiguity resolution (AR); and (2) estimating displacement of the marker's orientation. AR results in doubling the positioning accuracy, while displacement estimation enables the detection of any change in the marker's installation orientation and compensation for the effect thereof in the initialization process. Analytical results based on actual data acquired with a prototype system show that the above method and techniques work very well with a realistic setup of PPP-AR and marker performance, and successfully reduce the initial convergence time from tens of minutes to less than a minute.