Airborne surveillance

To keep an eye on the enemy activities deep inside the opponent’s territory, military commanders are increasingly relying on high speed data transfer which can be beamed from a powerful AWACS at a critical situation.

The AWACS, which has emerged as the 21st Century “Eye in the Sky”, can credibly meet the requirement of military planners and defence strategist in a unique way while it can be highly cost effective.

Airborne Early Warning and Control System (AWACS) aircraft is high value air asset in modern armed forces and homeland security departments, as they enable the forces which use them to have superiority over other forces deploying aircraft in a specific air space. AWACS is mobile, long-range radar surveillance and control centre used for air defence. AWACS is based on an airborne radar system installed on an aircraft, the main mission of which is to detect far off air targets. Even more so, it denies the enemy the use of that specific air space.

The AWACS was developed as consequence of increased air defence requirements that could not be met by ground based sensors. Besides, radar that functions on a dynamic airborne platform provides far more effectiveness in look-ahead capability as well as detailed coverage of a large volume of airspace, down to the ground level as it looks down. It offers better resolution, and provides ideal inputs for effective control and direction. More importantly, it multiplies the effectiveness of the Command and Control function.

AWACS is critical because it provides decision makers and commanders with key early warning intelligence, allowing them to make prompt decisions that will ensure their air superiority, in case of conflict.

From an early need of tracking low flying intruders against ground clutter, the airborne radar surveillance began as AEW&C and evolved as AWACS where its operational usage soon resulted in the expansion of its roles and capabilities-from early warning and control to providing complete real-time air situation picture to the commanders, and thus realize the important function of command and control as well as an airborne command post.

Due to increasing demand of network centricity in modern battlefield AWACS and other airborne surveillance sensors are at the heart of the efficacy of any C4ISR system.

AWACS play a major role on the modern battlefield by providing real-time intelligence and command and control needed to achieve and maintain air superiority over the combat area and to enable surveillance of borders in peacetime.

Even these days aircraft carrier based AWACS platform is also gaining significance to fulfill the role of the primary sensor. Fixed-wing AWACS platforms have superior coverage of airspace and more importantly have the ability to guide and control ship-borne fighters towards their targets, both in air defence and strike missions, an attribute lacking in the Airborne Early Warning (AEW) helicopter platforms.

The AWACS is also being used for homeland security missions, providing air surveillance of low flying airplanes involved in illicit activities such as smuggling , drug trafficking or insertion of goods and personnel related to terrorism. Furthermore, the organization of mass events often requires the use of aerial surveillance systems like AWACS for protecting against eventual terrorist threats.

AWACS is airborne radar system that detects incoming hostile fighters, cruise missiles and drones much before ground based radars. It also directs friendly fighters during combat operations with enemy jets while detecting enemy troops build up and warships.  Modern AWACS platforms are potent force multipliers with a range of almost 400 km. Mission system control (MSC) is the brain of the AEW&C system, as it incorporates all the data from sensors and other systems to control the whole system. It assesses threats using data received from the on-board sensors and other sources, and presents the Air Situation Picture (ASP).

It manages the whole communication system of the AEW&C system. The MSC can record the data and play back the same for conducting mission analysis. The Intercept Control Segment (ICS) integrated into the MSC will carry out recovery operations by guiding interceptors and vector strike aircraft.

Due to its multi mission capability, AWACS has now become an important tool for airborne surveillance for militaries around the world. Most of the countries in the world are now relying on information provided by AWACS platforms for their effective command and control operations.

The US has been a leader in developing advanced AWACS platforms and has seen success by using them in many conflicts where the country or its allies has been involved. Similarly Russia, Japan, Sweden, China and other countries in the world have also given priority of having AWACS as an important weapon for ensuring C4ISR capability.

India’s AWACS project

In recent years India has been shifting toward aircraft that would give it the ability to patrol and act at extended ranges. In January 2004, India and Israel signed a $1.1 billion contract for 3 Phalcon airborne warning and control system (AWACS) aircraft, as part of a $1.5 billion tripartite agreement with Russia. With the arrival of its first IL-76 Phalcon, India joined the global ranks of AWACS operators. The aircraft has to monitor huge swathes of Indian airspace, intercept communications and log radar frequencies, add some ground surveillance, and help command IAF responses.

AWACS capability was seen as an urgent need in India, so their initial effort focused on integrating proven systems from abroad.

India chose its IL-76TD medium jet transport as its base. IL-76/78 jets were well-proven within the IAF as strategic transports and aerial refueling tankers, and modified IL-76s already served in Russia as the A-50 AWACS.

In parallel, India has moved to implement AWACS capabilities on a smaller platform, in order to provide broader aircraft coverage of its territory. The goal there is to field a Tier 2 platform based on Embraer’s ERJ-145 jet, and Indian radar and electronics, allowing India to join the global ranks of AWACS designers.

Recently the India government cleared the DRDO project to build advanced next-generation AWACS which can detect incoming aerial threats like hostile fighters, drones and cruise missiles from 400-km away.

The Indian defence acquisitions council (DAC) approved the building of two AWACS, which will involve mounting indigenous 360-degree coverage AESA radars on Airbus A-330 wide-body jets, at a cost of Rs 5,113 crore.

The eventual plan is to induct eight such aircraft under the “AWACS-India” project since both China and Pakistan are well ahead of India in this critical area in modern-day warfare. Further six more AWACS will be ordered when the project is mid-way.

The “AWACS-India” project, with cost sharing between IAF and DRDO, is far more ambitious than the ongoing project to build three AEW&C (airborne early warning and control system) systems at a cost of Rs 2,275 crore. Under it, indigenous 240-degree coverage radars have been fitted on three smaller Brazilian Embraer-145 jets.

The AEW&C project is running years behind schedule, with the completion date now pushed back to December 2015. Project management is an important area of concern. Now that the IAF has had considerable operational experience in the operation of the AEW&C, it can contribute significantly with its operational database. It then becomes logical that the user manages the project if timelines are to be adhered to.

However the for procurement of two more Israeli Phalcon AWACS after the induction of the three is now in the final stages.

The nature of airborne threat to naval surface combatants has undergone a significant change lately.

These developments have necessitated the preferable tactics of destroying the attacking missile platform well before the missile is released to ensure a decent chance of survival of the defending vessels. Here AWACS have started playing an important role too.

The most successful aircraft carrier based AWACS platform is represented by Northrop Grumman E-2C ‘Hawkeye’. However the primary role of the E-2C Hawkeye aircraft is to operate as an all-weather AWACS platform to the naval task force capable of area and on-station search. From an operating altitude of 25,000 to 30,000-ft, the Hawkeye warns the naval task force of approaching air threats and provides threat identification and positional data to interceptors. Secondary roles include strike command and control, surveillance, guidance of search and rescue missions including support for anti highjack operations and as a relay to extend the range of communications between the airborne platforms and the Combat Information Centre (CIC) of the parent aircraft carrier.

India was also looking to acquire Hawkeye 2000 to be deployed on the Indigenous Aircraft Carrier (IAC) as these platforms will be ideally complemented by Indian Air Force Phalcons.

Aircraft carrier based Hawkeye 2000 will prove to be invaluable in enabling Indian Navy MiG-29K/KUBs to establish local air superiority in open oceans even within the range of enemy fighter and strike aircraft and will be instrumental in intercepting and destroying enemy strike and Long Range Maritime Patrol/Anti-Submarine Warfare (LRMP/ASW) platforms at great distances effectively.

Hawkeye meanwhile remains well within its development cycle with research proceeding on the next-generation, E-2E Advanced Hawkeye, to be fitted with a sophisticated next-generation solid-state, electronically steered Ultra-High Frequency (UHF) radar, Theatre Missile Defence (TBM) capabilities, multi-sensor integration and a Northrop Grumman Navigation Systems tactical cockpit.

Northrop Grumman’s E-2D Advanced Hawkeye is a game changer for naval forces in how they conduct battle management command and control. The E-2D gives the warfighter expanded battlespace awareness, especially in the area of information operations delivering battle management, theater air and missile defense, and multiple sensor fusion capabilities in an airborne system. With a two-generation leap in radar sensor capability and a robust network enabled capability, the advanced Hawkeye delivers critical, actionable data to joint forces and first responders. These advances provide warfighters with the necessary situational awareness to compress the time between initial awareness and active engagement.

AWACS platforms

Many countries have developed their own AWACS systems, although the Boeing E-3 Sentry and Northrop Grumman E-2 Hawkeye are the most common systems used worldwide.

Though, India is also not lacking behind. DRDO has developed a multisensor airborne early warning and control (AEW&C) system on a carrier jet, providing an airborne surveillance system in collaboration with CAB (Centre for Airborne Systems) for the Indian Air Force. It is the first native AEW system developed by DRDO and CAB. It was completely developed and built using the native technology platform. The AEW&C system is developed to serve the Indian Air Force in detection and tracking, identification and classification of threats, guidance and interception control, display of air situation picture and multisensor data integration. The system enables the armed forces to communicate with fighter jets and other AEW&C assets, while it also allows for Search and Rescue (SAR) operations, mission planning as well as record and replay for post mission analysis.

The jet platform selected for the DRDO AEW&C system is the Embraer EMB-145 from Brazil. The jet is modified to integrate mission systems. The cabin is also modified to house five operator work stations, four racks, additional fuselage fuel tanks and five rest crew seats. The modified aircraft has additional power unit to power onboard mission systems. It can also support the in-flight re-fuelling system for extended endurance of the mission.

The Government of India approved the AEW&C programme after the Indian Air Force (IAF) and Defence Research and Development Organisation (DRDO) jointly studied the feasibility of the AEW&C. Three EMB-145s were ordered by the Indian Government. The indigenous radar system of the DRDO was integrated after the aircraft was modified accordingly.

The system mainly comprises of a primary radar and secondary surveillance radar (SSR/IFF). The SSR provides Electronic Support Measures (ESM) and Communication Support Measures (CSM). It identifies and classifies the threats based on the emissions from them, and also serves as a Friend or Foe identification system.

The Indian AEW&C system uses C band data link, Ku band SATCOM and a set of five V/UHF frequencies. The C band and Ku band links form redundant links for air to ground communications.

The V/UHF frequencies are used for air to air data and voice communications. The communication systems allow the AEW&C system to communicate with satellites, radar ground control stations and more than 40 fighter aircraft.

E-3 platform

The E-3 airborne warning and control system (AWACS) is built by Boeing Defense & Space Group. The role of the E-3 is to carry out airborne surveillance, and command, control and communications (C3) functions for both tactical and air defence forces. In the USA the aircraft carries the designation E-3 AWACS. The UK designation is E-3 Sentry AEW (airborne early warning) and the French designation is E-3 SDA.

The role of the E-3 is to carry out airborne surveillance, and command, control and communications (C3) functions.

The E3 look-down radar has a 360° view of the horizon, and at operating altitudes has a range of more than 320km. The radar can detect and track air and sea targets simultaneously. In a tactical role, the E-3 can detect and track hostile aircraft operating at low altitudes over any terrain, and can identify and control friendly aircraft in the same airspace. In the strategic defence role, the E-3 provides the means to detect, identify, track and intercept airborne threats.

The basic E-3 aircraft is a militarised version of the Boeing 707-320B commercial jet airframe, distinguished by the addition of a large, rotating rotodome containing the main radar, identification friend or foe (IFF) and data-link fighter-control (TADIL-C) antennas.

The layout of the equipment in the fuselage is arranged in bays with areas allocated for communications, signal and data processing, command and control consoles, navigation and target identification systems. The aircraft is equipped with 14 command and control consoles fitted with high-resolution colour displays.

The primary radar housed in the rotodome is the Northrop Grumman AN/APY-1/2 AWACS radar. The radar transmitters, computers and display stations are housed within the fuselage. Boeing, with the electronic sensors and systems division of Northrop Grumman as subcontractor, carried out an E-3 AWACS radar system improvement program (RSIP) which upgrades the capability of the AN/APY-1/2 against threats from small radar cross section targets, cruise missiles and electronic countermeasures.

Experience has proven that the E-3 AWACS can respond quickly and effectively to a crisis and support worldwide military deployment operations. It is a jam-resistant system that has performed missions while experiencing heavy electronic countermeasures.

EMB- 145 platform

The EMB-145 AEW&C is a derivative of the Embraer ERJ-145 regional jetliner airframe, modified with the integration of an airborne early warning radar and mission system. The aircraft incorporates a reinforced airframe, new navigation and communication systems, an enhanced auxiliary power unit (APU), increased fuel capacity and a revised interior layout.

The EMB-145 AEW&C’s mission system is developed around the Ericsson ERIEYE active, phased-array pulse-Doppler radar and is integrated with an onboard command and control system. Electronic surveillance measures for monitoring communications and non-communications activities are also integrated with the system. The system comprises an active, phased-array pulse-Doppler radar including integrated secondary surveillance radar and identification friend or foe (SSR/IFF), a comprehensive, modular command-and-control system, electronic support measures (ESM), communications and datalinks.

Rather than conventional rotodome antenna system, ERIEYE has a fixed, dual-sided and electronically scanned antenna mounted on top of the fuselage. This places much less demand on aircraft size and is designed for mounting on commuter-type aircraft. The ERIEYE is capable of 360° detection and tracking of air and sea targets over the horizon. The instrumented range is 450km and a typical detection range against a fighter aircraft size target is in excess of 350km

Although capable of long endurance at normal patrol speeds, the EMB-145 has a high dash speed which contributes to survivability on patrol missions. The EMB-145 AEW&C crew includes the pilot and co-pilot, five mission systems specialists and up to three reserve crew members. The aircraft is equipped with five or six mission operator consoles.

The all-glass cockpit is fitted with five displays-primary flight displays, multi-function displays and the engine indication and crew alerting system (EICAS)-with multi-reversionary capabilities.

A-50 aircraft

The A-50 airborne early warning and control aircraft (AEW&C) was developed and manufactured by
the Beriev Aircraft Research and Engineering Complex Joint Stock Company, Russia. The A-50 aircraft was developed from the llyushin IL-76MD military transport aircraft.

The aircraft is known in the West by the NATO codename Mainstay. Beriev aircraft normally carry the Russian designation Be- followed by the number, however, the A-50 aircraft retained the well-known A-designation which Beriev allocated to the original prototype.

The A-50 aircraft detects and identifies airborne objects, determines their coordinates and flight path data and transfers the information to command posts. The A-50 also acts as a control centre, guiding fighter-interceptors and tactical air force aircraft to combat areas in order to attack ground targets at low altitudes. The role of the A-50 is comparable to that of the US’s E-3 AEW system.

The modernized A-50 aircraft can now take more fuel on board with the same take-off weight, while increasing the range and mission time performance. A satellite navigation system integrated into flight and navigation complex offers a dramatic increase in the navigational accuracy.

The A-50 aircraft was followed by four variants: A-50M, A-50U, A-50I and A-50E/I. The A-50M variant is an advanced version of the A-50 aircraft. The outdated analogue equipment of the A-50 have been replaced with digital electronics system to create the A-50M aircraft.

The A-50U is an updated Russian variant created by modernizing the element base of airborne radiotechnical complex, thereby reducing the total weight.

The A-50I is a variant specifically developed to meet the requirements of the Indian Air Force. It is additionally equipped with Israeli-made Phalcon radar. The variant, A-50E/I is an Israeli Phalcon radar export version.

The radar and guidance systems of A-50 have the capacity to track 50 to 60 targets simultaneously and to guide ten to 12 fighter aircraft simultaneously. The A-50 is fitted with a self-defence system when flying en-route and over patrol zones. The self-defence system ensures protection from guided and unguided weapons of the enemy’s fighters attacking the aircraft from its front and rear hemispheres. The self-defence system includes an electronic countermeasures system. The A-50 carries out patrol missions at an altitude of 5,000m to 10,000m.

The aircraft can also be protected from the enemy’s fighter aircraft via guidance of friendly fighters. The aircraft radio and electronics systems are robust against hostile jamming and provide good combat performance in dense electronic countermeasures environments.

Saab 2000

The Saab 2000 AEW&C airborne early warning and control aircraft is a variant of the Saab 2000 regional transport turboprop aircraft equipped with the spine-mounted Saab Systems Erieye PS-890 side-looking reconnaissance radar.

The aircraft, fully equipped for airborne early warning and control, can also be used for national security missions, border control, airborne command and control, disaster management coordination and for emergency air traffic control. The first customer for the Saab 2000 AEW&C was Pakistan.

The aircraft’s electronic warfare suite is based on the Saab Avitronics HES-21 electronic support measures (ESM) and self-protection suite. The HES-21 also provides a ground-based support system (EGSS), which provides mission data for the aircraft electronic warfare system and for analysis of recorded data.

The electronic support measures (ESM) system comprises digital narrow band and wide band receivers and associated antennae, providing close to 100 % probability of intercept (POI). The digital receiver is equipped with interferometer antenna arrays.

The aircraft can climb an altitude of 9,144m in 15 minutes. The maximum cruise and patrol speed of the aircraft are 629km/h and 296km/h respectively. The range is 3,218km. The take-off run of the aircraft is 1,400m and the maximum endurance is 9.5 hours. The aircraft weighs around 14,500kg and its maximum take-off weight is 23,000kg.

The self-protection system (SPS) comprises: defensive aids control system, radar warning, laser warning, missile approach warning and chaff and flare dispenser systems. The self-protection suite provides selection and, in automatic mode, the initiation of the chaff and countermeasures sequences.
Though ISR assets are as old as the WW II, the current network centricity is based upon radars and sensors for intelligence and surveillance and real time communication that have witnessed a technological leap.

Success in any conflict depends on ensuring accurate situational awareness at all levels-strategic, operational, and tactical. The role of information collectors, processors, and analysers is of critical importance in segments of operations. The variety of sensors and processing systems that aid decision making has grown enormously, In short, information has always been, and will always be central to the conduct of warfare, or rather the conduct of all kinds operations during peace and war. Therefore the role of AWACS will be critical in all future battlefield scenarios.