The beacon mode generates a separate beacon
frequency and an independent pulse with a PRI having
a range of 40,000 yds. The AN/SPQ-9B radar has
360-degree scan coverage for beacon targets. The
received beacon video is sent to the console for display
and distribution, while beacon track data is sent to the
computer for processing. The AN/SPQ-9B beacon
mode operates at the same time as the air and surface
modes.
The ASMD Sector function allows the air mode to
provide quick response detection of low-flying
high-threat targets. Through this function, the radar
automatically detects, tracks, and reports any targets
entering the ASMD sector that require a reaction time
of less than 30 seconds. The operator can select an
ASMD azimuth sector width between five and 360
degrees and a range of up to 20 NMI. The ASMD sector
function operates together with the air, surface, and
beacon modes.
The Surface-MTI Submode allows the surface
mode to cancel non-moving targets. The Surface-MTI
azimuth sector width is operator selectable between a
bearing width of five and 360 degrees, with the
AN/SPQ-9B automatically displaying any targets with
a relative speed exceeding 10 knots. The AN/SPQ-9B
R a d a r S u r f a c e - M T I s u b m o d e w i l l o p e r a t e
concurrently with the air, surface, and beacon modes.
The AN/SPQ-9B is installed on ships and aircraft
carriers in the following classes:
CG-47 TICONDEROGA class cruisers (figure
2-5)
LHD-1 amphibious ships (figure 2-2)
LPD-17 SAN ANTONIO class amphibious
ships
DD-963 SPRUANCE class destroyers (figure
2-10)
DDG-51 destroyers (figure 2-4)
The AN/SPQ-9 series radar also works with the
SPY-1 series radar. SPQ-9 radar helps to control a
number of weapons which include: SM-1/SM-2
missiles and the Mk 45 5”/54 gun.
Mk 23 Target Acquisition System (TAS)
The Mk 23 Target Acquisition System (TAS) is a
detection, tracking, identification, threat evaluation,
and weapon assignment system. It is used against
high-speed, small cross-section targets that approach
the ship from over the horizon at very low altitudes or
from very high altitudes at near vertical angles. The
TAS integrates a medium-range, two-dimensional,
air-search radar subsystem, an IFF subsystem, a
display subsystem, and a computer subsystem. This
allows TAS to provide automatic or manual target
detection and tracking, target identification, threat
evaluation, and weapon assignment capabilities for
engagement of air tracks. The Mk 23 TAS automatic
detection and tracking radar is also an element of the
Mk 91 Missile Fire Control system and is used on
SPRUANCE class destroyers, carriers, LHDs, LHAs,
and the LPD-17 class amphibious assault ships. The
Mk 91 MFCS and TAS control the SEASPARROW
missile as their primary weapon. Figure 2-9 shows a
Mk 29 box launcher for SEASPARROW missiles.
2-8
Figure 2-9.—Mk 29 box launcher for SEASPARROW missiles.
