FIG Peer Review Journal


Rigid Plate Transformations to Support PPP and Absolute Positioning in Africa (4858)

Richard Stanaway and Craig Roberts (Australia)
Mr. Richard Stanaway
University of New South Wales
PO Box 1364
Corresponding author Mr. Richard Stanaway (email: richard.stanaway[at], tel.: + 61 3 9486 7845)

[ 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


PPP, global RTK and GNSS post-processing services are now used extensively to provide realisations of ITRF and WGS84 globally with a precision of a few centimetres. Unless these instantaneous realisations are transformed to a static or semi-kinematic datum using a suitable kinematic transformation model, repeat surveys using these techniques will result in datum divergence as a function of time arising from the effects of unmodelled tectonic plate motion. Africa has a very sparse CORS infrastructure, and this limitation supports the use of PPP and related techniques. At present, there is no kinematic transformation applied through these services to maintain consistency of coordinate solutions, which account for plate motion. This paper describes a simple transformation strategy that can be applied on the African continent to enable instantaneous ITRF and WGS84 positions to be transformed to a specified reference epoch with a precision of a few centimeters on a decadal timescale. Adoption of this strategy will enable PPP and absolute ITRF positions to be transformed consistently to a fixed reference epoch for any given location in Africa not subject to localised deformation. The transformation parameters described are tested on a selection of IGS stations in Africa, and a worked example is shown to assist with implementation of the algorithm within software applications.
Keywords: GNSS/GPS; Positioning; Reference systems; Reference frames; Rigid Plate Transformations; ITRF; Kinematic Datums; PPP