MIM-104 Patriot is a mobile long-range air defence system with both anti-aircraft and anti-ballistic missile capabilities.

The development of the Patriot missile system can be tracked back in the 1960s. After the cancelation of SAM-A-19 Plato anti-ballistic missile project in February 1959, the US Army started the Field Army Ballistic Missile Defense System (FABMDS) program.

The General Electric design was accepted but in 1962, (US Army) came to the conclusion that the available technology cannot provide a cost-effective system. Thus, FABMDS program was also cancelled.

It was quickly replaced by the Army Air Defense 1970 (AADS-70) program. Renamed SAM-D (Surface-to-Air Missile - Development) in 1964, eleven years later, in 1975, a SAM-D missile successfully engaged a drone.

The following year, in 1976, SAM-D was renamed the PATRIOT Air Defense Missile System, and the development of the system went fully ahead.

The first Patriot units entered service in 1981 reaching the initial operational capacity in 1984.

At first, Patriot was used exclusively as an anti-aircraft missile system. The capability to engage ballistic missiles has been reached in the late 1980s when the Patriot Advanced Capability missile was introduced and the whole system received improvements.

Patriot elements

1. Radars:

1.1. The AN/MPQ-53 radar

The AN/MPQ-53 is a multifunction (G/H-Band) passive electronically scanned array radar for the Patriot PAC-2 units.

It has IFF (friend or foe identification), ECCM (electronic counter-countermeasure) and TVM (track-via-missile) capabilities.

Has a detection range between 3 and 170 km and is capable of tracking up to 100 targets and guiding up to nine PAC-2 missiles.

The radar is powered by the EPP (Electric Power Plant) and controlled by the Engagement Control Station (ECS).

1.2. The AN/MPQ-65 radar

AN/MPQ-65 is a (C-Band) passive electronically scanned phased array developed for both Patriot PAC-3 and PAC-2 units, replacing the older AN/MPQ-53.

AN/MPQ-65 radar has better search, detection, and tracking capability than the previous MPQ-53. This was obtained by adding a second traveling wave tube (TWT).

Mounted on M860 semi-trailers, MPQ-65 radar provides 120-degree coverage.

1.3. GaN-based active electronically scanned array (AESA) radar

Patriot will get a new AESA radar, based on Gallium nitride technology that will provide 360-degree coverage and will have a maintenance cost 50% lower than MPQ-65.

2. AN/MSQ-104 Engagement Control Station (ECS)

The Engagement Control Station (ECS) is the fire direction center of the Patriot system.

Trough a VHF data link antenna, which can be elevated to a height of 42 foot (12.8 m), the ECS can communicate with up to eight launching stations and control them.

Also, the ECS controls the radar, the electric power plant (EPP) and the antenna mast group (AMG), through data and control cables.

Inside the ECS shelter, are two operator stations, known as manstation one (MS1) and manstation three (MS3). Through these stations, the operators control the system during engagement.

The manstation two (MS2) is the voice communication station.

Other equipment part of the ECS are the weapon control computer, radar/weapon control interface unit, VHF data link terminal, VHF voice communication equipment and three UHF radio relay terminals.

3. OE-349 Antenna Mast Group (AMG)

The Antenna Mast Group (AMD) makes possible UHF communication between the Engagement Control Station (ECS), the AN/MSQ-116 Information and Coordination Central and the AN/MRC-137 Communications Relay Grpoup (CRG).

The OE-349 Antenna Mast Group consists of two remoted controlled masts that can be elevated to a height of 30.76 m (100 ft 11 in). On each mast, are two 4 kW antennas which can be controlled in azimuth.

4. Electric Power Plant (EPP) III

Consisting of two 150 kilowatt diesel generators connected to a power distribution assembly, the Diesel-Electric Power Plant (EPP) powers the radar and the AN/MSQ-104 Engagement Control Station (ECS).

The Electric Power Plant connects to the radar set by three power cables. The connection with the Engagement Control Station is made with a power cable and a control cable.

5. M901 Launching Station

The M901 Launching Station has four canisters, each of which can host a single PAC-2, PAC-2 GEM or PAC-2 GEM-T missile.

Being smaller in size, up to four PAC-3 and PAC-3 MSE missiles, can be fitted in one canister. Thus, each launching station can hold a maximum of 16 PAC-3 or PAC-3 MSE missiles.