Rifle Company, Infantry and Airborne Battle Groups - CIE Hub

evening civil twilight), EENT (end of evening nautical twilight),
moonrise, moonset, and the phase of the moon, are important in
determining visibility. At BMNT, enough light, under ideal conditions,
is available for infantry to effect close coordination among
individuals and to approach the enemy position relatively unobserved.
EENT is the last period of the day in which enough
light exists for such coordination. As a general rule, visibility at
BMCT is about 400 meters. At about halfway between BMNT and
BMCT (or EECT and EENT), there is enough light for ground
adjustment of close-in artillery fires. Visibility is affected by such
other conditions as cloud cover, fog, rain, snow, dust, and haze.
Rain, snow, freeze, or thaw may affect troop movements, particularly
by vehicle. Storms and extremes of temperature may
adversely affect personnel and equipment.
17. Terrain
Terrain is one of the major factors considered in the commander's
estimate of the situation. He studies the military aspects
of terrain described below to determine how he can best use the
terrain to aid in accomplishing his mission.
a. Observation and Fire. Observation assists in gaining information
of the enemy, in accurately directing fire on him, and in
controlling troops. Fields of fire are essential for the effective
employment of all available direct fire weapons. The commander
considers the available observation and fields of fire both from a
friendly and enemy point of view.
b. Concealment and Cover. Concealment is protection from
observation; cover is protection from fire. The commander determines
the concealment and cover available to both his company
and the enemy. He evaluates cover from the standpoint of protection
from the effects of flat trajectory fire, high angle fire, and
nuclear weapons. An area such as woods may provide concealment
from both air and ground observation; but little or no cover,
especially from high explosive shells and nuclear weapons.
c. Obstacles. Obstacles are either natural or artificial. They
should stop, delay, restrict, or divert movement. Natural obstacles
include such features as unfordable streams, swamps, very steep
slopes, and lakes. Artificial obstacles include those created by
nuclear or nonnuclear fires, minefields, flames, field expedients,
barbed wire entanglements, roadblocks, and antitank ditches. The
commander considers the effect of obstacles on friendly and enemy
movement of foot troops and wheeled and tracked vehicles.
d. Key Terrain Features. Any terrain feature whose seizure,
AGO 5508B 19