FIG Peer Review Journal


Locata: A New Constellation for High Accuracy Outdoor and Indoor Positioning (4917)

Chris Rizos, Yong Li, Nonie Politi, Joel Barnes and Nunzio Gambale (Australia)
Dr. Chris Rizos
School of Surveying & Spatial Information Systems
University of New South Wales
School of Surveying & SIS
University of New South Wales
Corresponding author Dr. Chris Rizos (email: c.rizos[at], tel.: + 61 2 93854205)

[ abstract ] [ paper ] [ handouts ]

Published on the web 2011-03-16
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


The Global Positioning System (GPS) is the best known, and only currently fully operational, Global Navigation Satellite System (GNSS) providing positioning capability anywhere in the globe, on a continuous 24/7 basis, with accuracies ranging from the dekametre-level to the sub-centimetre-level. Despite this versatility, GPS/GNSS cannot satisfy the high accuracy positioning requirements for many applications in engineering and mining surveying, machine guidance/control, structural monitoring, urban and indoor positioning. Russia has deployed its own GNSS called GLONASS which will be fully operational by the end of 2010. Fueling growth in precise positioning applications will be next generation GNSSs that are currently being developed and deployed, including the U.S.’s modernised GPS-IIF and GPS-III, the revitalised GLONASS, Europe’s GALILEO system, and China’s COMPASS system. Furthermore, a number of Space Based Augmentation Systems (SBASs) and Regional Navigation Satellite Systems (RNSSs) will add extra satellites and signals to the multi-constellation GNSS/RNSS ‘mix’. The main advantage that the multi-GNSS era will bring is more satellites. It is estimated that by 2015, if the planned deployments go ahead, there will be of the order of 150 – with perhaps six times the number of broadcast signals on which measurements can be made, compared to today’s GNSS availability. However, despite these planned extra satellite constellations the fundamental challenge of space-based positioning remains – to deliver high accuracy in areas where direct line-of-sight to four or more satellites is not available, as is the case in deep open-cut mines, heavily wooded, rugged terrain, urban and indoor environments. Locata’s positioning technology solution for either augmenting GNSS with extra terrestrial signals (as in the case where there is insufficient sky view for accurate and reliable GNSS positioning), or to replace GNSS (for indoor applications). Locata can therefore be considered a new type of localised “constellation”, able to provide high accuracy positioning coverage where GNSS fails. This paper introduces the technical aspects of this technology, summarises the R&D highlights, describes several tests that demonstrate a variety of applications for Locata, and presents some recent results of high accuracy outdoor and indoor positioning.
Keywords: GNSS/GPS; Positioning; Engineering survey; Locata; indoor positioning