Air Defense Artillery Control Systems
Modern CCCS are essentially specialized automatic data processing systems and,
as such, have shared in major state-of-the-art advances over the past few years.
As the vacuum tube gave way to the transistor, with its reduced size, weight, and
power requirements, so the transistor circuits of today have been replaced by
microminiaturized integrated circuits in new CCCS. Thus, the challenge of the
ever-increasing air threat is being countered by the most reliable and effective
command, control, and coordination equipment possible.
Radars used with the AN/GSG-5 system include defense acquisition radars AN/FPS-36,
AN/FPS-69, or any acquisition radar with a pulse rate of 200 to 400 pulses per second.
The radar furnishes target slant range and azimuth, hut no height data, to the AADCP.
The radar has IFF equipment which is used as an aid to identification.
The AADCP contains display equipment, computer and data storage facilities,
voice communications, and power and testing equipment. The situation display console
has controls and indicators that enable the controller to enter target identity,
position, and velocity into the memory system. The controls and indicators also
enable the controller to make or erase target assignments to batteries and to dump
data from the memory system. The plan position indicator (PPI) displays video from
the radar, local track symbols, SAGE/BUIC track symbols, battery return symbols,
and other symbols as selected by the controller.
Figure 33. Battery integration and radar display equipment (BIRDIE)
system AN/GSG-5.
Figure 34. AN/GSG-5 (BIRDIE) system.
The AN/GSG-5 can integrate a maximum of 16 Nike Hercules batteries and display
approximately 30 SAGE/BUIC and local tracks plus 16 battery returns. The automatic data
link (ADL) permits automatic transmission of digital data between BIRDIE and SAGE/BUIC.
The battery data link (BDL) transmits data from BIRDIE to the batteries. The batteries
transmit data back to BIRDIE and all other integrated batteries. The computer and storage
system allows semiautomatic tracking of targets up to a speed of 2,250 knots.
The data converter AN/GSA 77, described in detail later in this chapter,
which has replaced older battery terminal equipment in all ADA command, control,
and coordination systems, links the missile battery with the BIRDIE system.
The Missile Monitor (AN/MSG-4) command, control, and coordination system was developed
by the US Army to coordinate the fire of Nike Hercules and Hawk missile batteries with the
army in the field. These systems make it possible to observe and influence the entire air
battle from the widest viewpoint so separate actions of numerous batteries can be
supervised and unified into an integrated defense.
The AN/~IISG-4 system is composed of two basic subsystems: the AN/MSQ-28B or AN/MSq-56
sybsystem located at group-brigade level, and the AN/TSQ-38 subsystem (which is helicopter
transportable), located at battalion and battery level.
The AN/MSQ-2BB subsystem (fig 35) includes a frequency- scan, three -dimensional radar
AN/MPS-23A, a radar data processing center (RDPC), and a weapons monitoring center
(WMC). The AN/MPS-23A radar provides target detection, furnishing range, azimuth, and
elevation angle of the target. The antenna rotates mechanically in azimuth and scans
electronically in elevation. The AN/MPS-23A is equipped with IFF equipment.
The RDPC (fig 36) provides initial display of targets, a means for interrogation
of targets, and automatic tracking. Tracking is accomplished at six detector-tracker
(DT) consoles in the RDPC. Height data are observed on two range-height indicator
(RHI) consoles. The H, X, and Y coordinates of targets, plus X and Y velocities, are
stored as track data and sent to the WMC.
The WMC (fig 37) provides the group/brigade commander with an immediate presentation
of the tactical situation at all times. Track marker data are displayed in the form of
symbology on weapons monitoring consoles. Battery status also is received from the battery
and displayed on these consoles. This combined symbolic and read-out display of information
enables the commander to view the entire air battle and make assignments from the WMC to
the batteries under his control. The WMC can accept and utilize data from Air Force agencies
and adjacent defenses. The Missile Monitor system has the capability of directing more than
30 fire units against more than 150 targets.
The battalion-level component of the AN/TSQ-38 is the battalion operations central
(Bn OC) (fig 38). The BN OC gives the battalion commander the capability of either
monitoring reference data and the changing status, or making assignments to the
firing battery, depending upon the method of control and mode of operation. It links
the battalion uith the group WMC and fire units and displays battery status, target
video, and symbology on each of two consoles. The electronic search central AN/GSS-1
(or AN/GSS-7) of the battalion is connected to the Bn OC and can furnish radar data to
the Bn OC. In turn, the Bn OC can insert these data into the data link, thus providing
additional information to all fire units under WMC control in the normal mode of operation.
Figure 35. AN/MSQ-28B subsystem of Missile Monitor system.
Figure 38. Battalion operations central consoles.
The battery-level component used in conjunction with the AN/TSQ-38 is the data converter
AN/GSA-77. The data conveaer, which functions as a link between battalion and battery, is
a transmitter receiver that permits exchange of data between the battery and other elements
of the system. Information which may have originated at the WMC, BnOC, or other fire units
is received at the AN/GSA-77 in the form of binary digital data. The AN/GSA-77 converts
these data for display at the battery control console.
Information originating at the battery is converted to binary digital data by the
AN/GSA-77 and sent to the Bn OC and WMC.
The AN/MSG-4 system has six data link switching modes of operation. Only three of
these modes--normal, sector, and independent--are used in tactical operations. In the
normal mode, the WMC sends reference information and commands through the
Bn OC to the battery. The Bn OC monitors, but does not originate, commands to the
batteries. In the sector mode, reference information is sent to the Bn OC and the
batteries and the Bn OC originates commands to the batteries. In the independent mode,
all reference information and commands originate at the Bn OC. The other three modes
of operation are used for tests and emergencies.
The primary means of transmitting information, using binary digital data, is by
automatic data link. Common carriers of ADL include spiral-$ cable or microwave,
but any carrier capable of handling pulses made up of frequencies between 600 and
1875 hertz will suffice.
A new command, control, and coordination system, Missile Mentor(tlN/TSQ-51), has
been deployed in CONUS to replace some first-generation CCCS, including all Missile
Master systems. This new system is designed on the modular concept, allowing addition
or deletion of major functions so that requirements of various defense complexes may
be met with reduced operational costs, simplified maintenance, and increased
track-handling capability as compared to older systems. Data are automatically
exchanged by digital data link and voice communications with all defense elements,
including both Nike Hercules and Hawk fire units. This mobile AN/TSQ-51 system
requires no equipment air conditioning. The system integrates the operation of
surface-to-air missile ADA fire units by acquiring tracks, processing data, and
making track assignments to fire units. Each deployment site has a varying number
of associated fire units and remote data sources integrated into a coordinated air
defense system. Effective air defense command, control, and coordination are sustained
by the AN/TSQ-51 gathering and supplying up-to-date, real-time information on the air
situation, threat, and weapon availability.
Figure 39. AN/TSQ-51 operations trailer (interior view).
The AN/TSQ-51 system is comprised of two subsystems, the operations and equipment
trailers, which together serve as the Army air defense command post (AADCP), and
the remote radar integration station (RRIS). The RRIS, contained in one trailer, can be
used to provide radar gap-filler information as well as extend the effective radar range
of the defense. The operations trailer (fig 39) contains tracking and tactical display
(general purpose) consoles (fig 40) and operations boards. The equipment trailer
(fig 41) contains track equipment, including a general purpose digital computer.
The major functions performed by the system are target detection, acquisition,
identity, track correlation, threat evaluation, fire unitdesignation, and fire unit
status monitoring. The system gathers these data concerning its defense area and
extends the system coverage by analysis of track data from remote sources; i.e.,
semi-automatic ground environment (SAGE) system, backup interceptor control (BUIC),
RRIS stations, adjacent AADCP's, and surveillance radars. Actions are coordinated for
fire units under its command. The system operates in conjunction with standard
acquisition radars for local zone coverage. It has automatic and rate-aided manual
tracking facilities for keeping data current for local tracks. the operations trailer
equipment has been remoted into permanent facilities. Operation and maintenance of remoted
equipment are the same except for equipment cooling.
Figure 40. AN/TSQ-5l general purpose console.
The RRIS (fig 42) consists of one trailer containing tracking display (general purpose)
consoles, and a general purpose digital computer that differs from that in the equipment
trailer chiefly in its smaller memory capability. Each RRIS nets remotely located radars,
and each RRIS can compute data on tracks within its area of coverage and transmit data to
the parent AADCP. It also stores and displays data on AADCP-transmitted tracks.
The data converter AN/GSA-77 serves as the battery terminal equipment for the
AN/TSQ-51, performing the same functions as it does with the AN/MSG-4 system.
Figure 41. AN/TSW-51 equipment trailer (interion view)
Before any commander can engage an airborne threat, he must know the location of
the threat in relation to his unit. The location of the threat is expressed in terms
of azimuth, elevation, and range from the unit. In most current air defense artillery
command, control, and coordination systems, two types of radars are used to provide
these data: an acquisition radar to determine azimuth and range and a height-finder
radar to determine elevation. Use of two radars rather than one presents obvious
problems; e.g., two radars must be moved in a mobile situation, two radars must
be maintained and repair parts stocked for each, and two radars must be emplaced on
carefully selected terrain to prevent masking of the height finder radar so that
it can cover areas identical to those covered by the acquisition radar.
A three-dimensional (3D) radar can furnish all these data; i.e,, azimuth,
elevation, and range. This type of radar utilizes electronic scanning. One of the
later classes of electronic scanning radars, the AN/MPS-23 (a component of the
Missile Monitor FDS), provides three dimensional search. It supplies target azimuth,
elevation angle, and range data simultaneously from a single antenna (transmitter
and receiver) channel. The beam scans electronically in elevation while the antenna
rotates in azimuth. The antenna frequency-scan operation is similar in principle to
that of a slotted waveguide with the microwave energy radiated from the slots combining
to form a beam. When the frequency is matched and phased with the distance between
the slots, the direction of propagation is straight ahead. If the frequency of the
energy is changed, relative phase differences are set up from one slot to the next,
changing the direction of propagation accordingly. Continuous phase shifting is
achieved by using variable frequency exciters in the transmitter. These exciters
can be programed digitally to provide various patterns of beams scanning in elevation.
The AN/MPS-23 incorporates moving target indicator circuits that blank out returns
from stationary objects. It is capable of azimuth sector scanning a, well as
6,400-mil rotational scan. It provides variable scan rates in elevation and
azimuth and uses variable pulse repetition frequencies· The changing radiation
frequency gives this radar inherent resistance against electronic jamming.
Another proposed type of 3D radar incorporates many desirable characteristics,
such as mobility, compactness, light weight, ease of maintenance, and ability to
operate in an ECM environment Electronic equipment is sealed from such ambient
conditions as sand and dust, salt spray, rain, and humidity and is cooled by built-in,
air-to-air heat exchangers Transportable by helicopter, cargo aircraft, or standard
military vehicles, the lightweight 3D radar can be put into operation quickly at
remote sites. Rugged, compact design enables the entire system to be packaged in
two waterproof inclosures, 6.5 feet by 6.5 feet. The antenna package has a length
of 12 feet and weighs 2,300 pounds; the electric equipment shelter has a length of
9 feet and weighs 3,500 pounds.
The antenna inclosure of this radar is uniquely designed for transportability and
rapid assembly The pedestal and simplified aZimuth drive system are integral parts of
the lower portion of the antenna package, packed in the upper portion of the inclosure
are the reflector panels and waveguide lengths. The thin-shelled parabolic reflector
is assembled from four structural modules joined with quick-disconnect fasteners. Six
men can perform the entire assembly and hookup procedure.
All air defense must start with a knowledge of the attacking forces. As a result,
any air defense system must perform an aircraft tracking function which yields information
that commanders can use to engage the attacking force. This tracking function can exist
either as an integral feature of the air defense system, such as the defense acquisition
radar, or by the addition of radars specifically deployed for the purpose of early warning
or gap-filling.
The term, radar netting (fig 43), describes the process by which track data derived
from several additional or remote radars are gathered at a single center to produce an
integrated set of meaningful target information which can be distributed to all air
defense elements concerned.
Figure 43. Radar netting concept.
Radar netting can provide concurrent coverage of a selected area by more than one
radar. Each remote radar, independent of central computing facilities, can continue
to furnish processed track data to another user even if its primary user is disabled.
Another advantage is furnishing jam-strobe tracking or obtaining cross-hearings on a
jamming target to determine its position by triangulation.
A radar netting system exchanges data among various radars, surface-to-air missile
batteries, and command centers by advanced digital data transmission techniques. The
standard operational system consists of the following subsystems: radar tracking
station, radar netting unit, and battery terminal equipment.
The radar tracking station (fig 44) is a compact radar data processor which accepts
track information from its associated acquisition radar. This track information enters
the computer and is updated by manual tracking on the part of the console operator.
The computer stores the track data in digital form, which are then made available by
data link to any user in the netting system. The user receives position coordinates,
velocity components, laid size, identification, track number, and target height.
Figure 44 Radar tracking station (interior view).
Incoming track data irom each radar tracking station must be received at the
battalion operations central and relayed to the missile batteries as well as to the
other radar tracking stations. At the battalion operations central, the radar netting
unit (fig 45) acts as a sequencing and distribution device, channeling data from each
radar tracking station to the missile batteries through their terminal equipment,
to the battalion operations central displays, and to other radar tracking stations.
Data converter AN/GSA-77 (fig 46) is an onsite data processing unit that links
the missile battery to its command, control, and coordination system. It provides a
means of integrating both Nike Hercules and Hawk units into either the BIRDIE,
Missile Monitor, Missile Mentor, or Marine Tactical Data System. Digital commands
and target coordinate data, received over automatic data links from the CCCS, are
converted into suitable form for use by the weapon system. Battery status and
coordinates of the tracked target are encoded into digital form and transmitted
to the CCCS for use by the defense commander and retransmission to other batteries
of the defense.
Figure 46. Data converter AN/GSA-77.
Figure 47. Location of AN/GSA-77 in Nike Hercules and Hawk systems.
While the AN/GSA-77 normally exchanges data with other batteries through the
CCCS at the AADCP, it has the capability of communicating directly with adjacent
batteries over separate data links. If the AADCPitself is out of action, each battery
of the defense receives information on the actions of all other batteries. Upon loss
of one or more interbattery data links, the remaining linksare utilized in a manner
calculated to maximize information transfer. The various communication configurations
are automatically selected by the AN/GSA 77, although this selection may he manually
overridden by battery personnel.
The AN/GSA-77 is a microelectronic device which replaced FUIF and CDG. It is
mounted within the Nike Hercules director station or the Hawk battery control
central (fig 47), requires no air conditioning, and operates on only 178 watts of
400-hertz power. Automatic self-test, semiautomatic fault isolation plocedures,
onsite repair by replacement of throw-away, plug-in circuits, and general high
reliability of solid-state devices result in a significant increase in operational
readiness of air defense artillery units.
The present defense acquisition radars (DAR) have evolved from the early warning
radar AN/TPS-1. This radar included only the essentials required to provide early
warning information. Similar but not identicalequipment, the SCR-602A, appeared in
the military radar inventory during World War II. Later the AN/TPS-1B radar was
designed. The addition of moving target indicator circuitsto the AN/TPS-1 produced
the AN/TPS-1D, a medium-power search radar designed to detect targets in excess of
290 kilometers. It was first employed bythe Air Force and the Navy.
Subsequent issue of the AN/TPS-1D satisfied the requirement for long-range
radars at battalion level in air defense artillery units. In 1957, further
improvements were provided by more stable moving target indicator circuits, better
vertical antenna coverage, and a better display system which changed the nomenclature
to AN/TPS-1G.
To make the AN/TPS-1D and AN/TPS 1G radars more compatible with unit mobility,
they were packaged in a metal shelter, They also were assigned a new name, electronic
search central AN/GSS-1 (fig 48). In addition to the radar, the shelter contains radio
and telephone facilities, IFF equipment, and a manual plotting board. The shelter can
be mounted on a 2.5-ton truck and can serve as an emergency battalion AADCP. When
the larger 11- by 40-foot tripod-mounted antenna is provided with these radars, the
equipment becomes electronic search central AN/GSS-7 (fig 49).
Concurrently, the requirement for a radar with increased range for ARADCOM
units resulted in modification of these radars to provide a fixed early warning
radar, the AN/FPS-36. This radar employs the 11- by 40-foot antenna, which, with
receiver changes, improves the reception of radar returns and extends the range coverage.
Figure 48. Electronic search central AN/GSS-1.
Further modification of the AN/FPS-36 resulted in the AN/FPS-56 radar. This radar
consists of two AN/FPS-36 radars that transmit and receive through a common antenna,
thus providing two operating channels and increased reliability. The addition of ECCM
capabilities converted the AN/FPS-56 radar to the AN/FPS-61 (fig 50).
The modification of the AN/TPS family of radars did not cease with the development
of defense acquisition radars. These same radars are the basis for the development
of the alternate acquisition radars discussed in chapter 3.
If you have comments or suggestions, Send e-mail
to Ed Thelen
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Updated July 15, 1998
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Figure 36. Interior view of radar data processing center.
Figure 37. Interion view of weapons monitoring center.
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Figure 42. Remote radar integration station (interior view).
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Figure 45. Radar netting unit at battalion operations central.
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Figure 49. AN/GSS-7 antenna.
Figure 50. AN/FPS-61 radar.
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