Overview
Joint Surveillance Target Attack Radar System (JSTARS) is a long-range, C2BM (Command, Control and Battle Management), surveillance and target acquisition radar system designed by the US Army and US Air Force. This system was designed to classify, locate and track ground targets as well as to collect imagery and relays pictures to the base in all weather conditions.
JSTARS gives ground situation information through communication via secure data links with centres of military analysis, army mobile ground stations and air force command posts distant from the conflict location. It can determine the patterns, speed and direction of armed forces activity of helicopters and ground vehicles. It also provides image of the ground situation similar to that of the air situation provided by Air Warning and Control Systems (AWACS).
Development and Design
In 1982, United States Air Force and Army programs were merged for the development of new sensor technology E-8, which was tested on the Tacit Blue aircraft. In 1985, the first contract was given to Grumman Aerospace Corporation for the development of two E-8A systems. Even though these systems were under development, they were used in 1991 Operation Desert Storm to track the Iraqi armed forces under the direction of Albert J. Verderosa. It accommodated 49 combat maneuvers with a mission effectiveness rate of 100% and flew for more than 500 combat hours.
Boeing 707-300 series has been modified to E-8C JSTARS airframe that carries specialized communications, operations, control and radar subsystem. JSTARS aircraft propulsion system consists of four Pratt & Whitney JT3D-3B turbojet engines with a flight endurance of 11 hours or 20 hours with in-flight refueling system. In January 2007, the Pratt & Whitney and Seven Q Seven teams were selected to provide the JT8D-219 engine, including the new integrated propulsion pod system.
System and Radar
The synthetic aperture radar (SAR) can produce images of stationary objects. Besides its ability to locate, tract and detect large numbers of ground vehicles, it has a limited facility to detect slow-moving fixed-wing aircraft, rotating antennas and low, and helicopters.
The AN/APY-7 radar system can operate in fixed target indication (FTI), wide area surveillance, synthetic aperture radar (SAR), target classification and ground moving target indicator (GMTI) modes. An antenna is installed on the underside of the aircraft, which can be tilted for a 120 degree to either side of the plane to cover targets at more than 152 miles (250 km).
JSTARS gives ground situation information through communication via secure data links to the air force and army command centres. The secure digital data links include SCDL (Surveillance and Control Data Link) and SATCOM (Satellite Communications Link) for transmission of voice signal to the base and to JTIDS (Joint Tactical Information Distribution System). The JTIDS provides TADIL-J (Tactical Data Information Link-J) processing and generation and TACAN (Tactical Air Navigation) operation.
Characteristics
JSTARS technology was used in many operations like Kosovo War, Operation Enduring Freedom, Operation Iraqi Freedom, Operation Desert Storm, and recently in Afghanistan’s war. Some of the JSTARS characteristics are –
• Crew: four flight crew, plus 3 Army specialists and 15 Air Force (varies according to the mission).
• Length: 46.6 m (152 ft 11 in)
• Wingspan: 44.4 m (145 ft 9 in)
• Height: 13 m (42 ft 6 in)
• Max takeoff weight: 152,409 kg (336,000 lb)
• Power plant: 4× Pratt & Whitney TF33-102C turbofan engines
• Endurance: 9 hours (unrefueled)
• Cruise speed: optimum orbit speed 722 to 945 km/h (390 to 510 knots).
• Service ceiling: 12,802m (42,000 ft).
