PATRIOT is the abbreviaton of “Phased Array Tracking Radar to Intercept On Target”.
The MIM-104 Patriot is a surface-to-air missile (SAM) system, the primary of its kind used by the United States Army and several allied nations. It is manufactured by the Raytheon Company of the United States. Patriot is a long-range, all-altitude, all-weather air defense system to counter tactical ballistic missiles, cruise missiles and advanced aircraft. Patriot (MIM-104) is produced by Raytheon in Massachusetts and Lockheed Martin Missiles and Fire Control in Florida. As well as the USA, Patriot is in service in Egypt, Germany, Greece, Israel, Japan, Kuwait, the Netherlands, Saudi Arabia and Taiwan
- Missile Body Length: 520cm
- Missile Body Diameter: 40cm
- Fins: 4 x delta-shaped fins
- Fin Diameter: 85cm
- Range: 70km
- Maximum Altitude: Over 24km
- Time of Flight: Between 9 seconds and three and a half minutes
HOW PATRIOT WORK
The Patriot missile system has a remarkable goal to target. It is designed to detect, target and then hit an incoming missile that may be no more than 3 to 6 meters long and is typically flying at three to five times the speed of sound. The upgraded Patriot system can also destroy incoming aircraft and cruise missiles.
The Patriot missile system has been deployed in many situations because it is able to shoot down enemy missiles (e.g., Scud missiles) and protect soldiers and civilians from a missile attack. Patriot missile batteries were activated several times in the Iraqi war and were used extensively in the 1991 Gulf war. In this article, we will look at the technology that allows a Patriot missile to accomplish its goal.
Like the Stinger missile and the Sidewinder missile, the Patriot is a guided missile. However, the Patriot is somewhat more sophisticated. In both the Stinger and Sidewinder missiles, the infrared seeker is sensitive to engine heat. A human being is responsible for finding and identifying the target, appropriately aiming the missile so that the patriot heat-seeking eye can lock onto the target, and then firing the missile.
A Patriot missile, instead, depends on radar. The Patriot missile system uses its ground-based radarto find, identify and track the targets. An incoming missile could be 80.5 kilometers away when the Patriot's radar locks onto it. At that distance, the incoming missile would not even be visible to a human being, much less identifiable. It is even possible for the Patriot missile system to operate in a completely automatic mode with no human intervention at all. An incoming missile flying at Mach 5 is traveling approximately one mile every second. There just isn't a lot of time to react and respond once the missile is detected, making automatic detection and launching an important feature.
While the Stinger is a shoulder-launched weapon and the Sidewinder launches from aircraft, Patriot missiles are launched from Patriot missile batteries based on the ground. A typical battery has five components:
- The missiles themselves (MIM-104)
- The missile launcher, which holds, transports, aims and launches the missiles (M-901). This part is necessary because each missile weighs almost 1 ton.
- A radar antenna (MPQ-53 or MPQ-65) to detect incoming missiles.
- An equipment van known as the Engagement Control Station (ECS) houses computers and consoles to control the battery. (MSQ-104)
- A power plant truck equipped with two 150-kilowatt generators that provide power for the radar antenna and the ECS.
Since a Patriot missile battery can have up to 16 launchers, and there are also spare missiles to re-supply the launchers as missiles are fired, you can see that deploying a Patriot missile battery is not a small endeavor. Each launcher is roughly the size of a tractor-trailer rig, as is the ECS and the power supply truck. There are also operating personnel, technicians, support personnel, fuel for the generators, security forces to protect the battery.
PATRIOT ADVANCED CAPABILITY (PAC-3)
The Patriot Advanced Capability-3 (PAC-3) ballistic missile defense is the U.S. Defense Department’s priority short-range theatre ballistic missile defense program. The program is managed by the U.S. Army Lower Tier Project Office (LTPO) and is sponsored by the Missile Defense Agency (MDA).
The PAC-3 Missile is a high velocity interceptor that defeats incoming targets by direct, body-to-body impact. PAC-3 interceptors, when deployed in a battery, will significantly increase the system’s firepower, since 16 PAC-3s load-out on a launcher, compared with four of the Patriot PAC-2 interceptors.
The missile was first deployed during Operation Iraqi Freedom in March / April 2003. In February 2004, Lockheed Martin was awarded a production contract for 159 PAC-3 missiles, which includes 22 missiles to replace those expended in Iraq. Deliveries are to complete by April 2006.
A further contract for 156 missiles was received in February 2005. Of these missiles, 32 are for the Netherlands and 16 for Japan under foreign military sales (FMS) agreements. The Netherlands received the first PAC-3 missiles in October 2007. The US Army ordered another 112 missiles in May 2006 and 112 in March 2007.
Lockheed Martin was awarded a contract in January 2007 for the risk reduction/ concept definition of a programme for an air-launched Patriot PAC-3 missile system. The F-15C fighter would be the first aircraft to be fitted with the system.
In December 2007, the United Arab Emirates requested the foreign military sale of the Patriot system, including nine Patriot launchers, 288 PAC-3 missiles, 216 Patriot GEM-T missiles. The contract was awarded in December 2008. Kuwait has also requested 80 PAC-3 missiles and 60 GEM-T upgrade kits, a contract for the first six upgrade kits was placed in July 2008. In April 2008, Taiwan placed an order for a number of PAC-3 upgrade kits and, in October 2008, requested the sale of 330 PAC-3 missiles.
The Patriot system has four major operational functions:
- Command and control.
- Radar surveillance.
- Missile guidance.
The Patriot system is modular and highly mobile. All components consisting of fire control section included radar set, engagement control section, antenna mast group, electric power plant and launchers are truck or trailer mounted. The radar set and launchers (with missiles) are mounted on an M860 Semi-Trailers which are towed by an M983 "Dragon Wagon" HEMTT. A Patriot battery can prepare its equipment for movement (from firing posture) in approximately 30 minutes. The system can be emplaced from movement posture into firing posture in approximately 45 minutes. Missile reload is done using a M985E1 truck with a crane on the back. This crane is bigger than the standard crane found on most HEMTTs. Called a "Guided Missile Transporter" or GMT, this crane removes spent "cans" (empty missile canisters) off of the launcher. It then replaces them with fresh missiles. Because the crane nearly doubles the height of the HEMMT when not stowed, crews informally refer to it as the "scorpion tail".
A standard M983 with a regular sized crane is referred to as the LRPT (Large Repair Parts Transporter).
The heart of the Patriot battery is the fire control section and associated launchers, consisting of the AN/MPQ-53 or -65 Radar Set, the AN/MSQ-104 Engagement Control Station (usually referred to as the "ECS", the OE-349 Antenna Mast Group, and the EPP-III Electric Power Plant. The system's missiles are transported on and fired from the M901 Launching Station, which can carry up to four PAC-2 missiles or up to sixteen PAC-3 missiles. A Patriot battalion is also equipped with the Information Coordination Central, or ICC, a modified ECS which is designed to coordinate the fires of a battalion and uplink Patriot on to the JTIDS network.
THE AN/MSQ-104 ENGAGEMENT CONTROL STATION
The AN/MSQ-104 Engagement Control Station (ECS) is the nerve center of the Patriot firing battery. The ECS consists of a shelter which is mounted on the bed of an M927 5-Ton Cargo Truck or on the bed of a Light Medium Tactical Vehicle (LMTV) Cargo Truck. The main sub-components of the ECS are the Weapons Control Computer (WCC), the Data Link Terminal (DLT), the UHF communications array, the Routing Logic Radio Interface Unit (RLRIU) and the two "manstations" that is the system's man-machine interface. The ECS is air conditioned, pressurized (to resist chemical/biological attack), and shielded against Electromagnetic pulse (EMP) or other such electromagnetic interference. The ECS also contains several SINCGARS radios to facilitate voice communications.
The WCC is the main computer within the Patriot system. It is a 24-bit parallel militarized computer with fixed and floating point capability. It is organized in a multiprocessor configuration which operates at a maximum clock rate of 6 megahertz. This computer runs the operator interface, calculates missile intercept algorithms, and provides limited fault diagnostics. Compared to modern personal computers it has somewhat limited processing power, although it has been upgraded several times during Patriot's service life.
The DLT (Data Link Terminal) is the system which connects the ECS to Patriot's Launching Stations. It uses either a SINCGARS radio or fiber optic cables to transmit encrypted data between the ECS and the launchers. Through the DLT, the system operators can remotely emplace, slew or stow launchers, perform diagnostics on launchers or missiles, and fire missiles.
The UHF communications array consists of three UHF radio "stacks" and their associated patching and encrypting equipment. These radios are connected to the antennas of the OE-349 Antenna Mast Group, which are used to create UHF "shots" between sister Patriot batteries and their associated ICC. This creates a secure, real-time data network (known as PADIL, Patriot Data Information Link) which allows for the ICC to centralize control of its subordinate firing batteries.
The Routing Logic Radio Interface Unit (RLRIU) functions as the primary router for all data coming into the ECS. The RLRIU gives a firing battery an address on the battalion data network, and sends/receives data from across the battalion. It also "translates" data coming from the WCC to the DLT, facilitating communication with the launchers.
Patriot's Manstations are referred to as Manstation 1 and 3 (MS1 and MS3). These are the stations where Patriot operators interface with the system. The manstations consist of a monochrome (green and black) screen surrounded by various Switch Indicators. Each Manstation also has a traditional QWERTY keyboard and "isometric stick", a tiny joystick that functions much like the mouse of a PC. It is through these switch indicators and the Patriot user interface software (organized into dozens of separate pages known as "tabs") that the system is operated.
THE AN/MPQ-53 AND AN/MPQ-65 RADAR SET
The missile control radar AN/MPQ-53 is a frequency-agile multifunction G/H-Band radar group which performs entailed in the Patriot tactical air defence missile system. The antenna array is a 2.44 m diameter, 5,161-element phased-array planar configuration carried on a semi-trailer chassis. The antenna unit has separate arrays for target detection and tracking, missile guidance and IFF functions. The last of these tasks is carried out by an AN/TPX-46(V)7 interrogator, using a supplementary array adjacent the main circular search and track array on the antenna unit. Other supplementary arrays are for sidelobe cancellation and missile guidance signal reception.
The 3 to 170 km range radar performs its surveillance, tracking, guidance and Electronic Protective Measures (EPM) functions in a time-shared manner by using the system's computer to generate action cycles that last in milliseconds. Up to 32 different radar configurations can be called up with the beams tailored for long range, short range, horizon and clutter, guidance and EPM functions in terms of their power, waveform and physical dimensions. The data rate for each function can also be selected independently to give 54 different operational modes so that, for example, a long-range search can be conducted over a longer time period than a horizon search for low-altitude pop-up targets. None of the functions requires any given time interval which therefore allows a random sequence of radar actions at any one time, considerably adding to an attacker's ECM problem. The search sector is 90° and the track capability is 120°.The radar system has a capacity to track up to 100 targets and can provide missile guidance data for up to nine missiles.
The AN/MPQ-53/65 Radar Set is a passive electronically scanned array radar which is equipped with IFF, electronic counter-countermeasure (ECCM) and track-via-missile (TVM) guidance subsystems. The Patriot Radar operates in the NATO G band frequency range, between 4 and 6 GHz.
The AN/MPQ-53 Radar Set equips PAC-2 and older units, and the AN/MPQ-65 Radar Set equips PAC-3 units. The main difference between these two radars is the addition of a second traveling wave tube (TWT), which gives the -65 radar increased search, detection, and tracking capability. The radar's antenna array consists of over 5,000 elements which "flash" the radar's beam many times per second. Additionally, the radar's antenna array contains an IFF interrogator subsystem, a track-via-missile array, and at least one "sidelobe canceller" (SLC), a small array designed to decrease interference that might affect the radar. Patriot's radar is somewhat unique in that it is a "detection-to-kill" system, meaning that a single unit performs all search, identification, track, and engagement functions. This is in contrast to most SAM systems, where several different radars are necessary to perform all functions necessary to detect and engage targets. The detection range of the Patriot radar is in excess of 100 km, and it can simultaneously track up to 100 targets.
The beam created by the Patriot's flat phased array radar is comparatively very narrow and highly agile compared to a moving dish. This gives the radar its unmatched ability to detect small, fast targets like ballistic missiles, or low radar cross section targets such as stealth aircraft or cruise missiles. Additionally, the power and agility of Patriot's radar is highly resistant to countermeasures, including electronic countermeasures (ECM) radar jamming and radar warning receiver (RWR) equipment. Patriot is capable of quickly jumping between frequencies to resist jamming.The Patriot Radar costs $38 million.
The MPQ-53 Radar
- Weight : 79,008lb
- Length : 56.08ft
- Height : 11.83ft
- Width : 29.42ft
- Frequency : 4-6 GHz
- Range : 68km
- Detection Sector : 120deg
- Engagement Sector : 90deg
- Target Capacity : 50 simulations
- Missile Control Capacity : 9 in final engagement
AN/MPQ-64 Sentinel Air Defense Radar
- ·Radar Type:
o3-dimensional pencil beam
oRange-gated pulse Doppler
oPhase and frequency scanning
o30 rpm with electronic back-scan
- ·Secondary Radar: AN/TPX-56 IFF
- ·Track Selector: Elevation -10° to +55°, Azimuth : 360°
- ·Range: Up to 75 km
- ·Surveillance Sector:
oAdjustable horizon mask from digital terrain data base
o Azimuth : 360°
THE PATRIOT GUIDED MISSILE
There are a total of eight different variants of Patriot missiles: Standard, ASOJ/SOJC, PAC-2, PAC-2 GEM, GEM/C, GEM/T (or GEM+), and PAC-3.
The first fielded variant was the round MIM-104A, "Standard". It was optimized solely for engagements against aircraft and had very limited capability against ballistic missiles. It had a range of 70 km (44 miles), and a speed in excess of Mach 3. The MIM-104B "ASOJ" or "anti standoff jammer" is a missile designed to seek out and destroy ECM emitters. The MIM-104C PAC-2 missile was the first Patriot missile which was optimized for ballistic missile engagements. The GEM series of missiles (MIM-104D/E) are further refinements of the PAC-2 missile. The PAC-2's maximum range is reported to be around 160 km, and its speed was upgraded to Mach 5, making it substantially faster than the PAC-1. The PAC-3 missile is a totally new interceptor, featuring a Ka band active radar seeker, employing 'hit-to-kill' interception (in contrast to previous interceptors' method of exploding in the vicinity of the target, destroying it with shrapnel), and several other enhancements which dramatically increase its lethality against ballistic missiles. It has a substantially lower range of 15 km. The specific information for these different kinds of missiles are discussed in the "Upgrades" section.
The first seven of these are in the larger PAC-2 configuration of a single missile per can, four of which can be placed on a launcher. PAC-3 missile canisters contain four missiles, and as such sixteen rounds in total can be placed on a launcher. All Patriot missiles consist of a missile mounted within a canister that looks like a long box that is both the shipping and storage container and the launch tube. Patriot missiles are referred to as "certified rounds" as they leave the factory, and no additional maintenance is necessary on the missile prior to its being fired.
The PAC-2 missile is 5.31 meters long, weighs 900 kg and is propelled by a solid-fueled rocket motor at speeds in excess of Mach 5. The Patriot missiles cost between $1 and $3 million dollars per copy, depending on variant.
THE PATRIOT FUTURE
Patriot upgrades continue, with the most recent being new software known as PDB-6 (PDB standing for "Post Deployment Build"). This software will allow configuration 3 units to discriminate targets of all types, to include anti-radiation missile carriers, helicopters, unmanned aerial vehicles, and cruise missiles.
The PAC-3 missile is currently undergoing testing for a significant new upgrade, currently referred to as "MSE" or "Missile Segment Enhancement". The upgrade includes a new fin design and a new, more powerful rocket engine. The modification is alleged to increase the operational capability of the current PAC-3 missile up to 50% and is scheduled to be added to all existing PAC-3 missile stores by 2008.
Further upgrades to the dual-TWT radar set, the JTIDS uplink, and the system's processors and memory are scheduled to take place in the next few years.