(map; aerial; ground; supplement) (2-7)
Before physically examining the area, a preliminary study is made of the best available maps and aerial
photographs, to pan operations and routes of ground parties, to determine areas which need inspection from the air,
and to anticipate conditions which may be encountered by personnel operating in the area.
The best available ______________________________ and ___________________ __________________ are
used for a preliminary study of the area.
(obscured; grounded) (2-31)
On single photographs, terrain relief is not discernible. If overlapping stereo pairs have been flown, relief can
be perceived and measured, but the stereoplotting equipment and trained personnel needed are generally only
available to topo units.
Stereophotography and stereo plotters are needed in order to perceive and measure ______________________.