Optical method for measuring bed topography and flow depth in an experimental flume 1Equipe de Dynamique des Fluides Géologiques, Institut de Physique du Globe de Paris (IPGP, UMR 7154, CNRS, Univ. Paris Diderot), 1 rue Jussieu, 75238 Paris Cedex 05, France
28 Jul 2011
2Department of Physics and Astronomy, University of Pennsylvania, 209 S. 33rd St., Philadelphia, PA 19104, USA
*now at: Univ. Aix-Marseille, CEREGE UMR 6635, Europôle de l'Arbois, BP 80, 13545 Aix-en-Provence cedex 04, France
Received: 01 Mar 2011 – Published in Solid Earth Discuss.: 15 Mar 2011 Abstract. We describe an optical method known as moiré for acquiring quasi-simultaneous
measurements of bed topography and flow depth in laboratory experiments. The moiré method
is based on projecting a fringe pattern (grating) on the bed and analyzing the deformation
of the pattern caused by the topography with respect to a reference plane. The height
of the object is encoded in the phase of the pattern and can be retrieved either through
Fourier transform or phase shifting algorithms. The methodology enables image-based
non-contact measurements over a continuous surface at very high spatial and temporal
resolutions. We use a commercial software package of a moiré method called Light3D to
map bed topography and flow depth in an experimental braided channel and demonstrate
how the method can be used to characterize a full range of statistics not previously possible.
Revised: 17 Jun 2011 – Accepted: 07 Jul 2011 – Published: 28 Jul 2011
Citation: Limare, A., Tal, M., Reitz, M. D., Lajeunesse, E., and Métivier, F.: Optical method for measuring bed topography and flow depth in an experimental flume, Solid Earth, 2, 143-154, doi:10.5194/se-2-143-2011, 2011.