Noise
Due to the training that occurs at FMR, only small arms noise contours have been
modeled. Small arms weapons typically refer to hand‐held and easily portable weapons
of .50 caliber or less that are primarily used against personnel and lightly armored or
unarmored equipment. The Small Arms Range Noise Assessment Model is the computer
program used by the Army to model small arms noise zones. It uses the peak noise level
and incorporates the most up‐to‐date information available on weapons noise source
models, sound propagation, ricochet barriers, noise mitigation and safety structures, and
the direction weapons are fired to create the noise zones.
The noise zones that were modeled for FMR represent a maximum small arms training
scenario where all ranges are actively firing. This event is unlikely to occur due to the
overlap of some ranges and their associated safety zones. However, there are also
individual events where noise generated is louder than the model that is generated
based on an average. Noise Zone III falls entirely within the boundary of FMR. Noise
Zone II extends outside the boundary for approximately 4,000 feet to the east, 2,300 feet
to the south, and 3,700 feet to the west. However, there is currently minimal
development in this area, and there are very few noise‐sensitive uses. The noise zones
are illustrated on Figure 2.
Safety
Weapon Surface Danger Zones
A surface danger zone (SDZ) is an area around a weapons firing range from which the
access of all military personnel and civilians is restricted due to the inherent dangers
associated with the firing of live munitions. An SDZ can include the surface (and
subsurface) of land and water, as well as the air space overhead through which
projectiles are launched. An SDZ includes the weapons firing position, the target
impact area, and a secondary buffer area, which is an additional distance where errant
projectile / munitions fragments may land without risking harm to life or property.
Surface danger zones vary in size and shape depending on the type of weapon(s) fired,
their firing location, and the projectile trajectory.
Each of the firing ranges at FMR has an associated SDZ based on the type of weapons
fired at that range. For simplicity, the SDZs are initially modeled on a 2‐dimensional
plane. Some of the 2‐dimensional SDZs at FMR extend outside the installation’s
boundary onto privately‐owned land. For this reason, the AZARNG has modeled
3‐dimensional SDZs that consider the terrain around these ranges. When terrain features
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Arizona Army National Guard Profile