AWACS (Airborne Warning And Control System) is the central pillar of modern air defence systems and the most effective means by which a nation can avert the catastrophe of a surprise air attack. Surface-based radar which rely on short wavelengths for detection are limited to line-of-sight observations and oblivious to aircraft beyond the horizon (BVR). Even with careful positioning of the surface radar on mountaintops, the time between a fast enemy aircraft/missile being sighted and weapons being released is too little for effective countermeasures, assuming that correct identification of the enemy was instantaneous.
On the other hand owing to its elevation the AWACS has the advantage of a greater radar horizon compared to ground-based radar, which translates to surveillance of a larger chunk of airspace. A single AWACS of the E-3 class, on patrol at an altitude of say nine kilometres, could have the capability to provide surveillance up to a range of 400 km at low level and detect up to 600 targets. It incorporates technology sophisticated enough to direct up to 30 interceptions simultaneously. In addition the AWACS has a data link facility to pass target information to ground-based radar and the air defence network. An AWACS would also possess inherent ECM (Electronic Counter Measures) capability making it a difficult proposition for a hostile air force to electronically interfere with its operations. As far as its endurance is concerned, the AWACS has a patrol time of 8–16 hours on station depending on the type of aircraft used..
The radar of an AWACS platform has multi-mode operations to maximize detection possibilities. Modern AWACS radar are pulse-Doppler type like the Westinghouse AN/APY-1 mounted on the the rear fuselage of the Boeing E-3 Sentry of the United States Air Force (USAF). Mounted on the back of the aerial within the same saucer-shaped envelope is the complementary antenna of TADIL-C IFF (Identification Friend or Foe) and secondary surveillance radar. The pulse-Doppler radar permits AWACS platforms to locate targets flying close to the ground, filtering out “clutter†by Doppler shift induced in reflected signal pulses. By using a sharp beam and narrow Doppler filter, very low-level intruders can be tracked with accuracy in the PDNES (Pulse-Doppler Non-Elevation Scan) mode. If target elevation is required, the returning signal is electronically scanned in the vertical plane to elicit the data, this being known as PDES (Pulse-Doppler Elevation Scan) mode.
For targets beyond the horizon, there is BTH (Beyond The Horizon) scan available using the pulse radar without the Doppler option because ground clutter is in the shadow of the horizon. The AN/APY-1 or upgraded AN/APY-2 of Boeing E-3 Sentry radar operated within the rotodome rotates at a rate of 6 rpm, giving a scan every 10 seconds. Operation frequency is in the 10 centimetres wavelength, with seven operating modes, including a PDES, PDNES, BTH, a short-pulsed maritime mode, passive, and a test/maintenance and standby modes. However AWACS is mainly designed for defection of low level targets and its ability to pick up targets above its own level is limited.
For maritime operations, a very short pulse is employed to reduce the sea clutter and so reveal the moving and stationary vessels. Maps of coastal areas stored in the aircrafts computer automatically remove shoreline returns from the screen. Not only can the AWACS provide air battle management at sea, but also guide own aircraft to carry out anti-ship strikes. In addition it can make available data for OTH (Over-The-Horizon) targeting of ships by own missiles.
Finally there is the passive mode in which the radar is silent and only the ESM (Electronic Support Measures) equipment is listening for signs of radar and radio transmissions from other airborne platforms and ships. Again it is possible to “go passive†only in selected segments of the compass and interleave radar modes in each scan. ESM equipment and IFF (Identification Friend or Foe) are important complements to the radar.
Data received by all sensors is processed by an on-board computer like the IBM CC-2 onboard the E-3 Sentry, filtered for extraneous signals and presented to the tactical crew inside. The avionics automatically open a file on each new plot, track its progress and correlate radar ESM and IFF returns. In the display screens, clear computer-generated pictures appear in which each target is annotated with its vital characteristics. Under leadership of a tactical-controller the tactical crew manage target tracks and handle communications with airborne and ground units. In this context the E-3 employs the Link16 JTIDS (Joint Tactical Information Distribution System) and has quick secure voice communications.
The E-3 Sentry type of AWACS has a low-level coverage of 400 km and a patrol time of 8 hours on task. With this AWACS flying 150 km inside one's own territory, the lateral coverage along the border would be 750 km for each aircraft. Therefore, it could fly a racecourse pattern and still cover a 600 km long segment inside enemy territory for 8 hours.
During the Gulf War, the Russian A-50 “Mainstay†operating over the Southern Black Sea and Caucasus area, were observed flying sorties to monitor 'Coalition Forces' air operations in Turkey and Northern Iraq. Air patrol operations were reported as normally conducted at 10,000 metres flying ‘figure of eight’ flight patterns, with up to 100 kilometres between orbit centres.
The effect of AWACS platforms were well apparent during the war between Israel and Syria over Beka'a Valley in 1982, when the Israelis mercilessly decimated the Syrian Air Force in conjunction with their excellent battle management system. The Israeli example in Beka’a valley is often considered the classic exploitation of AWACS asymmetry since the Syrians did not posses such a system. Even in offensive air operations, the AWACS can guide own strike aircraft to enemy targets while steering them clear of their air defences. The Syrian Air Force decided to provide air cover to facilitate deployment of Syrian SAM (Surface-to-Air Missile) units on Beka’a valley but were overwhelmed by “array of†Israeli E-2C "Hawkeye" AWACS platforms, static balloons, RF-4E reconnaissance fighters, OV-1 "Mohawk" battlefield surveillance platforms and specially equipped Boeing RC-707s. Additionally all the Israeli fighters had data-links to process real time information and also the excellent Shafrir and AIM-9L "all aspect" WVR (Within Visual Range) missiles. The Syrian fighters were tracked as soon as they left the runaway and the Israelis enjoyed the vital tactical advantage of surprise. The result was the loss of over 80 Syrian aircraft as against 2 Israeli fighters. 36 of the Syrian fighters were MiG-23s. In addition the Syrian data-links were jammed.
Finally, the impact of an AWACS platform as an airborne command post need to be emphasised. AWACS will be invaluable in reconfirming enemy airborne targets at extended ranges, so that BVR (Beyond Visual Range) air-to-air missiles can be despatched with surety to decimate them. This process of reconfirmation is necessary since even today positive BVR identification presents growing challenges. No more will the fighter pilots have to follow the risky "eyeball/shooter" sequence, where the flight leader comes unacceptably close to the enemy formation for positive identification and passes the data to other fighters. His associates then fire the BVR missiles with devastating effect.
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On the other hand owing to its elevation the AWACS has the advantage of a greater radar horizon compared to ground-based radar, which translates to surveillance of a larger chunk of airspace. A single AWACS of the E-3 class, on patrol at an altitude of say nine kilometres, could have the capability to provide surveillance up to a range of 400 km at low level and detect up to 600 targets. It incorporates technology sophisticated enough to direct up to 30 interceptions simultaneously. In addition the AWACS has a data link facility to pass target information to ground-based radar and the air defence network. An AWACS would also possess inherent ECM (Electronic Counter Measures) capability making it a difficult proposition for a hostile air force to electronically interfere with its operations. As far as its endurance is concerned, the AWACS has a patrol time of 8–16 hours on station depending on the type of aircraft used..
The radar of an AWACS platform has multi-mode operations to maximize detection possibilities. Modern AWACS radar are pulse-Doppler type like the Westinghouse AN/APY-1 mounted on the the rear fuselage of the Boeing E-3 Sentry of the United States Air Force (USAF). Mounted on the back of the aerial within the same saucer-shaped envelope is the complementary antenna of TADIL-C IFF (Identification Friend or Foe) and secondary surveillance radar. The pulse-Doppler radar permits AWACS platforms to locate targets flying close to the ground, filtering out “clutter†by Doppler shift induced in reflected signal pulses. By using a sharp beam and narrow Doppler filter, very low-level intruders can be tracked with accuracy in the PDNES (Pulse-Doppler Non-Elevation Scan) mode. If target elevation is required, the returning signal is electronically scanned in the vertical plane to elicit the data, this being known as PDES (Pulse-Doppler Elevation Scan) mode.
For targets beyond the horizon, there is BTH (Beyond The Horizon) scan available using the pulse radar without the Doppler option because ground clutter is in the shadow of the horizon. The AN/APY-1 or upgraded AN/APY-2 of Boeing E-3 Sentry radar operated within the rotodome rotates at a rate of 6 rpm, giving a scan every 10 seconds. Operation frequency is in the 10 centimetres wavelength, with seven operating modes, including a PDES, PDNES, BTH, a short-pulsed maritime mode, passive, and a test/maintenance and standby modes. However AWACS is mainly designed for defection of low level targets and its ability to pick up targets above its own level is limited.
For maritime operations, a very short pulse is employed to reduce the sea clutter and so reveal the moving and stationary vessels. Maps of coastal areas stored in the aircrafts computer automatically remove shoreline returns from the screen. Not only can the AWACS provide air battle management at sea, but also guide own aircraft to carry out anti-ship strikes. In addition it can make available data for OTH (Over-The-Horizon) targeting of ships by own missiles.
Finally there is the passive mode in which the radar is silent and only the ESM (Electronic Support Measures) equipment is listening for signs of radar and radio transmissions from other airborne platforms and ships. Again it is possible to “go passive†only in selected segments of the compass and interleave radar modes in each scan. ESM equipment and IFF (Identification Friend or Foe) are important complements to the radar.
Data received by all sensors is processed by an on-board computer like the IBM CC-2 onboard the E-3 Sentry, filtered for extraneous signals and presented to the tactical crew inside. The avionics automatically open a file on each new plot, track its progress and correlate radar ESM and IFF returns. In the display screens, clear computer-generated pictures appear in which each target is annotated with its vital characteristics. Under leadership of a tactical-controller the tactical crew manage target tracks and handle communications with airborne and ground units. In this context the E-3 employs the Link16 JTIDS (Joint Tactical Information Distribution System) and has quick secure voice communications.
The E-3 Sentry type of AWACS has a low-level coverage of 400 km and a patrol time of 8 hours on task. With this AWACS flying 150 km inside one's own territory, the lateral coverage along the border would be 750 km for each aircraft. Therefore, it could fly a racecourse pattern and still cover a 600 km long segment inside enemy territory for 8 hours.
During the Gulf War, the Russian A-50 “Mainstay†operating over the Southern Black Sea and Caucasus area, were observed flying sorties to monitor 'Coalition Forces' air operations in Turkey and Northern Iraq. Air patrol operations were reported as normally conducted at 10,000 metres flying ‘figure of eight’ flight patterns, with up to 100 kilometres between orbit centres.
The effect of AWACS platforms were well apparent during the war between Israel and Syria over Beka'a Valley in 1982, when the Israelis mercilessly decimated the Syrian Air Force in conjunction with their excellent battle management system. The Israeli example in Beka’a valley is often considered the classic exploitation of AWACS asymmetry since the Syrians did not posses such a system. Even in offensive air operations, the AWACS can guide own strike aircraft to enemy targets while steering them clear of their air defences. The Syrian Air Force decided to provide air cover to facilitate deployment of Syrian SAM (Surface-to-Air Missile) units on Beka’a valley but were overwhelmed by “array of†Israeli E-2C "Hawkeye" AWACS platforms, static balloons, RF-4E reconnaissance fighters, OV-1 "Mohawk" battlefield surveillance platforms and specially equipped Boeing RC-707s. Additionally all the Israeli fighters had data-links to process real time information and also the excellent Shafrir and AIM-9L "all aspect" WVR (Within Visual Range) missiles. The Syrian fighters were tracked as soon as they left the runaway and the Israelis enjoyed the vital tactical advantage of surprise. The result was the loss of over 80 Syrian aircraft as against 2 Israeli fighters. 36 of the Syrian fighters were MiG-23s. In addition the Syrian data-links were jammed.
Finally, the impact of an AWACS platform as an airborne command post need to be emphasised. AWACS will be invaluable in reconfirming enemy airborne targets at extended ranges, so that BVR (Beyond Visual Range) air-to-air missiles can be despatched with surety to decimate them. This process of reconfirmation is necessary since even today positive BVR identification presents growing challenges. No more will the fighter pilots have to follow the risky "eyeball/shooter" sequence, where the flight leader comes unacceptably close to the enemy formation for positive identification and passes the data to other fighters. His associates then fire the BVR missiles with devastating effect.
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PM one of the mods when you have the link and we'll unlock the thread for comment
