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Proceedings Paper

Hazards of reverse projection from hand-held cameras
Author(s): James R. Williamson
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Paper Abstract

To individuals working with photogrammetric analysis (dimensional reconstruction) of close- range photogrammetry using hand-held or video cameras there are certain situation tasks confronting them with a dimensional reconstruction analysis from a reverse projection procedure. Close-range reverse projection is analogous to completing a resection procedure manually, i.e., either the original negative, or an enlarged positive is aligned (position and orientation) to locate the original camera station. The tasks could require verifying the accuracy of a reverse projection procedure application; or, the task could be as an expert witness in opposition to another expert using reverse projection. The method of reverse projection is for all practical purposes an uncontrolled close-range photogrammetric attempt at aerial rectification. This discussion quantitatively defines the errors associated with the close- range reverse projection through two examples. To compound the error propagation the photograph provided for analysis is usually a cropped enlargement, e.g., 3' X 5', 8' X 10', and so on.

Paper Details

Date Published: 15 October 1993
PDF: 11 pages
Proc. SPIE 1943, State-of-the-Art Mapping, (15 October 1993); doi: 10.1117/12.157140
Show Author Affiliations
James R. Williamson, Supportware Inc. (United States)

Published in SPIE Proceedings Vol. 1943:
State-of-the-Art Mapping
Bill P. Clark; Andy Douglas; Bryan L. Foley; Brian Huberty; LeLand D. Whitmill, Editor(s)

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