There
are three test ranges:
- NATO FORACS AUTEC (NFA)
in the Bahamas.
- NATO FORACS Greece (NFG) near Souda Bay, Crete,
- NATO FORACS Norway (NFN) near Stavanger, and
Each test range has dockside facilities for one-day
preparation of the ship. The on-range operating area is
approximately 7 x 10 km along an open-ocean shore-line.
The on-range control building provides target generation,
data processing, and range safety surveillance. Each
range also includes a shallow water area, equipped with
mine shapes for testing mine hunting sonars.
Tracking
Model of FORACS Tracking
System |
A NATO FORACS range
is equipped with optical and Differential
GPS tracking instrumentation which is capable
of fixing a reference point on the ship within
1 meter of accuracy.
The ship's general plans are used
during the dockside phase to determine the location of
each sensor on-board the ship relative to the FORACS
reference point. A theodolite aligned to the centerline
of the ship tracks an optical target ashore to provide a
measurement of ship's heading to better than 0.03 degrees
depending on weather conditions. From the measurements
above, the x-y location and orientation of each shipboard
sensor are calculated.
Navigation Systems
Accuracies of shipboard GPS and other navigation
systems are tested against the data (approximately 1
meter) generated by the FORACS tracking systems.
Targets
Model of FORACS Targets
Acoustic
- Active sonar range errors are measured at
dockside using a portable sonar transponder (500
Hz to 50 kHz).
- Active sonar range and bearing performance
on-range is measured using bottom-mounted
transducer arrays connected to shore-based
electronics by underwater cable. The frequency
range is from 2 to 50 kHz; maximum pulse length
is 10 seconds. In addition to synthesized CW and
FM pulse signals, an echo repeater mode is
available whereby an actual sonar transmission
may be captured, precisely delayed, and
re-transmitted. A Doppler offset may be added if
required.
- Mine hunting sonars up to 600 kHz can be tested
dockside using a High Frequency test set capable
of precise range delays. Dynamic bearing and
range accuracy is tested using bottom-mounted
mine shapes and acoustic reflectors.
- Passive sonar bearing accuracy is tested with the
underwater targets connected to a noise generator
- filter - amplifier ashore. Noise signals are
available throughout the range of 400 Hz to 50
kHz with the width of the noise bands adjustable
through appropriate filter settings.
Installation
of a FORACS Acoustic Target
Click on picture
to enlarge
Electro-Magnetic
- Radar transponders generate targets in the
frequency range
1 to 18 GHz and 26 to 40 GHz, with pulse
modulation capability equivalent to the
transmitted radar signal (maximum spectral band
width: 30 MHz).
- Radar reflectors are also used for passive
electro-magnetic targets.
- Electronic Warfare Support Measures (ESM) signal
sources provide a computer-controlled ESM target
system which is capable of transmitting up to
eight different signals simultaneously in the
band
2 to 18 GHz with the additional capability of
simulating specific radars whose characteristics
are stored in memory.
Fixed frequency transmissions are available at 24
and 35 GHz.
Electro-Optical
- An optical prism reflector target is used for
range accuracy tests of lasers.
- Infrared sensors are tested against a high
intensity lamp target, which is also used for
tests of TV tracking systems.
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