Through-water close range digital photogrammetry in flume and field environments

Détails

ID Serval
serval:BIB_6280AE89BCDE
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Through-water close range digital photogrammetry in flume and field environments
Périodique
PHOTOGRAMMETRIC RECORD
Auteur(s)
Butler JB, Lane SN, Chandler JH, Porfiri E
ISSN
0031-868X
Statut éditorial
Publié
Date de publication
04/2002
Volume
17
Numéro
99
Pages
419-439
Notes
ISI:000175775300003
Résumé
Measurment of the structure of gravel-bed river surfaces is crucial for
understanding both bed roughness and the Sediment entrainment Process.
This paper describes the use of close range digital photogrammetry to
measure and monitor change occurring in submerged river gravel-beds in
both flume and field environments. High-resolution digital elevation
models (DEMs) were obtained and two-media (through air and water)
techniques were used to correct for the effects of refraction at the
air/water interface. Although suitable refractive models have been
developed, the use of proprietary software to generate DEMs
automatically introduces the problem of how to re-establish
collinearity. A simple refraction correction algorithm based upon
analytical geometry was developed and is described. This algorithm was
designed for use after initial DEM acquisition and allows any
photogrammetric software package to be used for data acquisition.
Application of this algorithm led to improvements in DEM accuracy by
reducing the systematic, width-dependent bias caused by refraction.
Research carried out in a flume environment allowed the algorithm to
;be tested by measuring a flooded and drained bed surface.
Non-systematic differences between the ``dry'' and ``wet'' DEMs arose
from reductions in stereomatching success in the two-media case. This
effect was thought to be due to light attenuation and the introduction
of residual parallax. Results suggest that close range digital
photogrammetry can be used to extract highquality DEMs of submerged
topography in both flame and field flurial environments, which
represents a particularly exciting development for fluvial
geomorphologists.
Web of science
Création de la notice
03/02/2011 15:41
Dernière modification de la notice
20/08/2019 15:19
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