Range Determination Using Target Images
Publication: Journal of Surveying Engineering
Volume 120, Issue 4
Abstract
An inexpensive and simple technique was developed for the survey of inaccessible objects, in which the image of the target is formed at an accessible location by means of an optical beam splitter. The three dimensions of the inaccessible object are determined from measurements conducted at the location of the object image and observed through the transparent component of the beam splitter. A simple prototype was built for tall vertical structures, horizontal or inclined roofs, and objects at potentially dangerous locations. With this prototype, the image may be formed at a convenient location for conducting the measurements, and cross sections can be determined at different planes. The beam splitter of the prototype is a 50/50 reflectance/transmittance half‐silvered mirror. The technique was used to subdivide a distance between two inaccessible targets, and also to map an ancient dome for restoration purposes. The time saved with the proposed technique in comparison with indirect theodolite surveying is considerable. The accuracy obtained matches the accuracy of optical distance‐measurement techniques, and can be largely increased by using prism‐binocular field glasses.
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References
1.
Ahmed, F. A. (1989). “Optimization and automation of inaccessible target surveying.” The Australian Surveyor, June.
2.
Ahmed, F. (1984). “Photogrammetric application of a video system in three‐dimensional recording.” Photogrammetric Engrg., 5(5), 593–596.
3.
Altman, J. H., and Ball, R. C. (1961). “On the spatial stability of photogrammetric plates.” Photogrammetric Sci. and Engrg., 5, 278–282.
4.
Hottier, P. H. (1976). “Accuracy of close range analytical restitutions: practical experiment and prediction.” Photogrammetric Engrg. and Remote Sensing, 42(3), 345–375.
5.
Karara, H. M. (1967). “Universal stereoscopic systems.” Photogrammetric Engrg., 33(11).
6.
Manual of photogrammetry (1966). American Society of Photogrammetry, 517–522.
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Copyright
Copyright © 1994 American Society of Civil Engineers.
History
Received: Jul 12, 1993
Published online: Nov 1, 1994
Published in print: Nov 1994
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