Photogrammetric uses of a new-generation analytical stereoplotter in forestry

by Kiser, Jim (James

Abstract (Summary)
The development of personal computer software

coupled to an analytical stereoplotter allows major gains

in efficiency and accuracy in a number of forestry related

subjects. This thesis describes the operation of a system

developed by Carto Instruments.

This thesis demonstrates how area estimates might be

made in a systematic way within 5% of true values by

accounting for topographic displacement, non-horizontal

flight, and imprecise determination of scale, factors that

conventionally result in errors of more than 25%. Ground

distances were accurate within 3% at 300 feet on 1:31000

scale black and white prints. At a similar scale, tree

heights ranging from 40 to 100 feet could be consistently

estimated within 10% of true height.

When applied to mapping the location of snags, key

features of riparian zones, and changes in canopy

openings, the system proved satisfactory on various filni

media and scales. Historical analysis of aerial

photographs was demonstrated by adjusting to common scale

and measuring rates of vegetation change over four decades

toward canopy closure. The same approach has application

for other historical analysis where aerial photographs are


The application of the system to terrestrial

photogrammetry was demonstrated using 35 mm transparencies

to measure tree taper within an accuracy of 2 inches.

In summary, merging of software written for a

personal computer has finally made the benefits of

analytical stereoplotting economically available to a host

of forestry-related topics and provides an opportunity for

numerous applications including, as demonstrated, a more

accurate digitizing of data to be included in any

geographic information system.

Bibliographical Information:

Advisor:Paine, David P.; Sessions, John; Waring, Richard; Harrington, Tim

School:Oregon State University

School Location:USA - Oregon

Source Type:Master's Thesis

Keywords:analytical plotters photogrammetry forest surveys data processing aerial photography in forestry


Date of Publication:08/26/1991

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