Citation

Sarvothama. Indian Highw. 1980; 8(1): 12-19.

Copyright

(Copyright © 1980, Indian Roads Congress)

DOI

unavailable

PMID

unavailable

Abstract

The author states that an aerial photograph is the basic tool used by the photo interpreter. Aids to photo interpretation are broadly grouped under qualitative aspects of aerial photographs and the quantitative metric measurements that can be obtained from them. Ranges of scale suggested for different stages of highway works are given. Measurements of size of objects in highway planning and locations such as groups of hutments, rows of trees, heaps of stones can be distinguished by measuring planer dimensions and their heights. The shape of the object represents its structure composition and function. These aids furnish the approximate dimensions of culverts, roadside gutters, heights of trees, intervening obstacles and other such essential data for route location. Shadows cast by objects, tone and colour, texture, pattern elements indicating surface and sub-surface are also discussed along with stereoscopic examinations of photographs. A detailed description is given of interpretation of highway photographs along with photo interpretation keys and their classification. (TRRL)