is desirable.
Where vegetation is dense, stereo photographs are preferred.
(2) Stereo pair separate plants from background and simplify analytical
study. Distant views give a clear idea of the vegetation coverage of the area.
3.
Photography of Soil Types.
a. General.
Pictorial documentation of various types of soil within a
specified area, indicating rock outcrops and positive or negative conditions
relating to trafficability, is an important supplement to terrain photography.
Features to be emphasized are:
(1) Details of soil and rock texture.
(2) Soil firmness or lack of firmness.
(3) Terrain slope.
b. Coverage.
Appropriate documentation is accomplished through medium and
close-up views, both single frame and stereoscopic. Stereo pairs are produced to
show rock outcrops and soil conditions.
Soil texture can be indicated by
photographing a handful of soil.
c. Trafficability.
Documentation photography, both aerial and ground, can
be used to determine trafficability. For example, the tracks of a vehicle with
varying loads can be photographed on a representative road or cross-country area
for purposes of comparison.
The impressions made by the wheels will indicate
wheel-bearing characteristics of that type road or soil.
A ruler should be
included in each photograph to illustrate the depth of the impression.
The
amount of loading carried by the vehicle must be stated on the data control sheet
of every photograph.
d. Supporting documentation.
Close-up photographs can be supported by one
or more long shots to establish the location of the pictorial target with respect
to pertinent environmental terrain features.
4.
Panoramic Terrain Photography.
a. Panoramics are a series of overlapping photographs carefully matched and
joined to form a composite wide-angle view of selected terrain of targets. There
are two basic types of panoramics, varying in respect to image detail and to
method of production.
(1) The first and most common, known as swing panoramic, involves the
selection of an ideal viewpoint and the exposure of a series of still negatives
by rotating the camera on its tripod after each exposure to provide a series of
overlapping images.
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