Accession Number : AD0660906

Title :   PECULIARITIES OF IDENTIFYING FIELD PREPARATION POINTS UNDER CONDITIONS OF SHIFTING SANDS,

Corporate Author : AERONAUTICAL CHART AND INFORMATION CENTER ST LOUIS MO LINGUISTIC SECTION

Personal Author(s) : Alekseev-Shemyakin,V. P. ; Fedorova,O. S.

Report Date : OCT 1967

Pagination or Media Count : 16

Abstract : In a stereographic survey of shifting sands, the greatest difficulty is met in the local identification of field inspection points for horizontal and vertical control. On all air photos, the vegetation in sandy deserts is distinguished by the difficulty of recognizing individual plants. In the formation of the point image it becomes almost impossible to distinguish the shrub, the mound around it and the shadow of the shrub and mound. For air photo identification it is necessary to take into consideration wide, sessile crown shrubs, treelike crown shrubs and weedy growths. The time exposure should be chosen so that the main parts of the cast shadows do not cover nearby shrubs and so that the low growths are not covered the borchan's shadows. A study of photos from repeated flights over a single tract of desert was made. It was photographed 4 times in 8 years. Several conclusions were drawn from the tables made from this study, among them that identification of feature points in standard picture portions was possible in only about 40% of all photos. After 8 years only 3% to 5% of the feature points were identifiable. Methods and suggestions are given for taking flight photos in which field feature points will be identifiable more readily. (Author)

Descriptors :   (*PHOTOGRAMMETRY, PHOTOINTERPRETATION), STEREOPHOTOGRAPHY, MAPPING, IDENTIFICATION, TERRAIN, DESERTS, PHOTOGRAPHIC ANALYSIS, USSR

Subject Categories : Cartography and Aerial Photography

Distribution Statement : APPROVED FOR PUBLIC RELEASE