A critical problem in hydraulics research is accurate measurement of
fluvially worked sediments, both in the field and in scaled
representations of field situations in laboratory flumes. Such
measurement must provide information on individual gran
characteristics, and their organisation into structures referred to as
bedforms. Existing measurement approaches are based upon mechanical or
laser profiling devices, which are both expensive and take considerable
time to acquire data, particularly where information is required at
very high densities. This paper demonstrates how conventional automated
terrain model taction software, combined with image acquisition using a
Kodak DCS460 digital camera, has been effective in generating digital
elevation models of complex bed morphology. This has reduced time spent
collecting data in the flume and has allowed data collection at much
higher spatial and temporal densities. Application of the method is
illustrated by research carried out at Hydraulics Research Wallingford.
Issues discussed include configuration of photographs and control
coordinates; appropriate camera calibration methods stability of inner
orientation of the Kodak DCS460; and accuracies obtained. Comparisons
with independent check data reveal that accuracies of +/-2.5 mm have
been achieved using a camera-to-object distance of 4.2 m.