FIG Peer Review Journal


Positioning in Active Deformation Zones - Implications for NetworkRTK and GNSS Processing Engines (8012)

Paul Denys and Christopher Pearson (New Zealand)
Dr Paul Denys
School of Surveying
Otago University
PO Box 56
New Zealand
Corresponding author Dr Paul Denys (email: pdenys[at], tel.: +64 3 4797596)

[ abstract ] [ paper ] [ handouts ]

Published on the web 2016-03-01
Received 2015-11-10 / Accepted 2016-02-01
This paper is one of selection of papers published for the FIG Working Week 2016 in Christchurch, New Zealand and has undergone the FIG Peer Review Process.

FIG Working Week 2016
ISBN 978-87-92853-52-3 ISSN 2307-4086


New Zealand’s actively deforming landscape results in both gradual and imperceptible deformation to instantaneous block shifts. The geophysical processes that cause the deformation include the tectonic plate motion (slow, regular deformation), earthquake events (instantaneous coseismic deformation), post-seismic relaxation (slow regular deformation) and slow slip events (irregular deformation occurring at timescales from days to years). Network RTK (NetworkRTK) and GNSS processing engines are current day positioning applications that need to be able to accommodate deformation that may be slow or fast, regular or irregular, in order to maintain accurate and reliable coordinates. Most commercial software can only apply velocities that are assumed to be linear. Deformation effects that are non-linear are not accounted for, which potentially leads to inaccurate coordinates. There are two aspects that need to be considered. The first is the ability to model the reference station coordinates, e.g. NetworkRTK. Secondly, the ability to model and transform non-reference station coordinates to the local datum, e.g. the rover positions computed using NetworkRTK and the positions derived from GNSS processing engine. For reference station coordinates, geodetic time series modeling can be used to accurately model both linear and non-linear deformation. But it becomes more challenging to model non-uniform deformation at non-reference positions. This paper considers examples in New Zealand of non-linear deformation that includes post-seismic relaxation and slow slip events.
Keywords: GNSS/GPS; Deformation measurement; Reference frames; Active Deformation Dynamic datums