Whilst such movements and measurements of change
are useful to the structural engineer, the full potential of
the digital photogrammetric technique can only be
Vector Scale 10mm
Section Scale 100mm
Figure 12 Exaggerated change in section of the rotor
blade between epochs 10 and 17.
realised if this information is amalgamated with data from
other instrumentation. A programme of structural
experiments featuring research into the combination of
disparate data from different instrumentation and the
visualisation of pertinent engineering information thus
derived is currently in progress.
7. CONCLUSIONS
In conclusion, for photogrammetry to achieve its
undoubted potential in the structural testing environment,
research is required to extend and adapt existing data
capture, processing and visualisation technologies for on
site use by engineers. Further work is necessary not only
to ensure and enhance data quality, but also to provide
the seamless integration of data from a wide variety of
instrumentation.
This application of a low cost digital photogrammetric
system to the analysis of small scale structural
deformation has demonstrated the quantity of information
of verifiable quality which can be rapidly obtained. There
is no doubt that more can be achieved if imaging and
experimental conditions are carefully designed. The
rudimentary digital photogrammetric system used, whilst
limited in image resolution, data acquisition rate and local
computing power, has proved successful such that the
key element of the project is the representation of the
data in a form suitable for interpretation by the engineer.
Work is currently in progress to design and build a new
more powerful system which can be used to routinely
monitor larger objects both in the laboratory and on site.
Work on a methodology to include the variation of lens
distortion with object space which is applicable to both
laboratory and uncontrolled environments is currently in
progress.
498
8. REFERENCES
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1840
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Cooper, M.A.R., and Robson. S. 1994. Photogrammetric
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Fraser, C.S., and Gruendig, 1988. The analysis of
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Robson, S., Brewer, A., Cooper, M.A.R., Clarke, T.A.,
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Robson, S., and Cooper, M.A.R., 1995. Digital
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Setan, H., 1995. S-Transformations: A practical
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Strang van Hees, G.L, 1982. Variance-covariance
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International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B5. Vienna 1996
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