FIG Peer Review Journal


Test Results of Locata Technology for Deformation Monitoring (4928)

Mazher Choudhury and Chris Rizos (Australia)
Mr. Mazher Choudhury
The University of New South Wales
164/B Botany St
Corresponding author Mr. Mazher Choudhury (email: mohammad.choudhury[at], tel.: + 61 423355034)

[ abstract ] [ paper ] [ handouts ]

Published on the web 2011-02-10
Received 2010-11-22 / Accepted 2011-02-10
This paper is one of selection of papers published for the FIG Working Week 2011 in Marrakech, Morocco and has undergone the FIG Peer Review Process.

FIG Working Week 2011
ISBN 978-87-90907-92-1 ISSN 2307-4086


Deformation monitoring requires very high levels of precision as well as accuracy. Although GNSS is a popular choice for 24/7 deformation monitoring applications, it suffers from interference and multipath vulnerability. In addition, the number of visible satellites and their geometric distribution plays an important role in the resultant accuracy and precision. To address these shortcomings, Locata Corporation invented a positioning technology called “Locata”. Locata provides position solutions using a network (a “LocataNet”) of time-synchronised pseudolite-like transceivers (or “LocataLites”) which can be installed almost anywhere for better network geometry. As soon as a Locata receiver tracks four or more LocataLite signals it can compute millimetre-level precise and millimetre-to-centimetre-level accurate position entirely independent of GPS. As these ranging signals have frequencies in the licence-free 2.4GHz Industry Scientific and Medical (ISM) band, other devices that also use the ISM band may cause degradation of Locata’s position solution. This paper evaluates the performance of the Locata technology in the presence of interfering signals. Zero baseline (ZBL) tests are used to observe the performance of two Locata receivers in conditions ranging from benign to hostile (high signal interference). Results from ZBL tests help to identify several research directions which can be pursued in order to improve Locata’s position solution for static applications such as deformation monitoring.
Keywords: Deformation measurement; static positioning; Locata