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Title: MONITORING LANDSLIDE MOVEMENT WITH A 35-MM CAMERA
Accession Number: 00468616
Record Type: Component
Availability: Find a library where document is available Abstract: The methods of analytical photogrammetry and microcomputer technology are combined to generate contour maps or cross sections, or both, of landslides along roadways with minimal conventional surveying. A conventional 35-mm camera and 8-in. by 10-in. photographs are used for the mapping. A minimum of two overlapping photographs are needed of the area to be mapped. Also, a minimum of six well-distributed control points are needed. Control points are points for which position (X and Y coordinate pair) and elevation (Z) must be obtained by conventional surveying techniques. The photogrammetric model used is the direct linear transformation model. This model uses x and y coordinates of corresponding images on two or more photographs to determine the position and elevation of such images in a ground-based coordinate system. A microcomputer performs the calculations and an electronic digitizer connected to the microcomputer is used to obtain the image coordinates on the photograph. The ouput can be in the form of a coordinate list of desired points, cross sections, a contour map, or three-dimensional perspective plot. The graphics are generated by a pen plotter connected to the microcomputer. Studies indicate that the error vector at about 400 ft is 0.4 ft for this system of mapping. A slope in distress can be monitored over a period of time. To eliminate resurvey, the six control points have to be located in a stable area.
Supplemental Notes: Publication of this paper sponsored by Committee on Soils and Rock Instrumentation. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
Monograph Title: Monograph Accession #: 01418086
Authors: Ballantyne, J DDean Jr, D RThompson, B LPagination: pp 47-54
Publication Date: 1987
Serial: ISBN: 0309044723
Media Type: Print
Features: Figures
(1)
; References
(6)
; Tables
(1)
TRT Terms: Old TRIS Terms: Subject Areas: Geotechnology; Highways; I42: Soil Mechanics
Files: TRIS, TRB
Created Date: May 31 1988 12:00AM
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