Apache’s Longbow Radar enables rapid, multi-target engagement in all weather, over multiple terrains and through battlefield obscurants

Rajesh Uppal November 28, 2019 Air Force Comments Off on Apache’s Longbow Radar enables rapid, multi-target engagement in all weather, over multiple terrains and through battlefield obscurants 3,211 Views

Radars have emerged as most effective sensors for long range detection and tracking of military targets under all weather, day/night conditions. Radar is an essential electronic system for any military force, whether at land, sea, or in the air. Over the years military radar technology has gradually moved to higher frequencies, smaller antennas, and solid-state amplification in place of the triodes and magnetron vacuum tubes of the early radar systems. Over the past 30 years, radar systems have improved performance due to advances in technology, such as phased-array radars, active electronically scanned array (AESA) technology, and synthetic aperture radars (SARs).

Northrop and Lockheed Martin have developed together a well-known radar system, the AN/APG-78 “Longbow” fire-control radar system. Using Ka-band frequencies, the compact radar system has an effective detection range of 8 km. Fielded on the U.S. Army’s Apache AH-64D attack helicopter, the Longbow radar features low probability of intercept and can detect and locate multiple moving and stationary targets. It works in conjunction with the millimeter-wave-guided HELLFIRE Fire and Forget missile to lock onto a target before or after launch.

For more than a decade, the LONGBOW FCR has enabled Apache aircrews to automatically detect, locate, classify and prioritize multiple moving and stationary targets on land, air and water in all weather and battlefield conditions to the maximum range of the Longbow missile (8 kilometers). It can scan an area searching for potential targets presenting to the aircrew the top 16 of 100 targets in less than 6 seconds. It enables rapid, multi-target engagement in all weather, over multiple terrains and through battlefield obscurants.

The Apache LONGBOW system is a proven force multiplier that has been battle-proven in Operation Enduring Freedom and Operation Iraqi Freedom. In the days of fighting against the hordes of “Russian tanks”, the AH-64D (and now the AH-64E) would “hide behind” hills, hovering so the Longbow disk is just looking over the ridge. It can then spot an enemy tank, lock-onto it, and then pop-up and fire a few Hellfire anti-tank missiles and then re-hide.

International Customers

Earlier Longbow secured a foreign military sale contract from the US Army to provide fire control radar (FCR) systems for the Indian Air Force (IAF). Valued at $57.1m, the contract requires the company to produce and supply 12 FCR systems and spares for IAF’s new Apache AH-64E helicopters. India becomes 11th International Customer for LONGBOW LLC’s Apache Radar. The APG-78 Fire Control Radar (FCR) has been provided to the United States AH-64D Longbow Apache (Block II) helicopters, as well as, those operated by the United Kingdom, Israel, Kuwait, Greece, Japan and Singapore.

Lockheed Martin Missiles and Fire Control Longbow programmes president and director Jim Messina said: “With Longbow FCR, the Indian Air Force will receive a rapid all-weather targeting capability. “The FCR’s air over-watch mode provides aircrews with 360-degree situational awareness, improving survivability and mission success.”

The fire control radars on the South Korean Army’s AH-64E Apache Guardian helicopters are unable to properly detect enemy targets due to software glitches and the absence of a naval detection capability, according to the Defense Acquisition Program Administration in Oct 2018. The South Korean Army operates two battalions of 36 AH-64E Apache Guardian attack helicopters, which had been acquired under a 2013 FMS deal valued $1.6 billion.

Six of the 36 Boeing-built AH-64E helicopters, bought via the U.S. Foreign Military Sales route, are fitted with the Lockheed Martin-developed Longbow fire control radar. The top-mounted sensor suite for target acquisition is known for its ability to simultaneously detect 128 targets up to 12 kilometers away with precision.

However, during an air assault operational test held between last October and November, the radar failed to properly recognize the number of targets, as it mistook four designated targets for 101 targets, according to a DAPA report to Rep. Lee Jong-myung, a lawmaker of the main opposition Korea Liberty Party. In separate tests in a mountainous area, the radar mistook 18 targets that were 6 kilometers away for nine targets, and 18 targets that were 3 kilometers away for five targets. During a test over water, the radar failed to detect any target.

“The main purpose of acquiring these Apache attack helicopters was to help detect and thwart a possible infiltration by North Korean high-speed boats or hovercraft into the western coast of border islands,” said Lee, a member of the National Assembly’s Defense Committee. “Without a proper operational capability of the radar, however, it could not be fully operated for such missions.”

The legislator also noted the Apaches would be limited in the transfer of battlefield information to ground forces because its data link communications devices, such as Link-K, are still under development.

The LONGBOW Limited Liability Company, a joint venture of Lockheed Martin [NYSE: LMT] and Northrop Grumman Corporation [NYSE: NOC], received a $181 million contract from the U.S. Army for AH-64D Apache Block III LONGBOW systems. The contract includes the first international purchase of the Block III LONGBOW Fire Control Radar (FCR) by Taiwan, which will receive 15 Block III LONGBOW FCR systems.

LONGBOW FCR

The Longbow is a modification of the Apache helicopter which is comprised of a Fire Control Radar (FCR), a fire-and-forget millimeter wave-guided Longbow Hellfire missile, and the all-digital M299 launcher for the AH-64 Apache helicopter. Nearly 400 radars and more than 14,000 missiles have been contracted for the U.S. Army and international customers.

The Apache Longbow can automatically engage multiple targets, enable precision attacks in adverse weather conditions, provide fire and forget missile capability, and operate on the digital battlefield of the future. The U.S. Army testing of LONGBOW system shows its integrated capabilities enhance the Apache lethality fourfold and survivability sevenfold. It has scored 100% in many live-fire exercises proving missile’s operational capability with the FCR and other targeting systems, as well as its ability to strike targets at maximum range in adverse conditions.

The Longbow FCR, used in conjunction with a radio frequency interferometer (RFI), provides high performance with very low probability of intercept. The self-contained RFI allows accurate determination of the direction to enemy air defense units, allowing the opportunity for preemptive suppression from standoff range or evasion. Longbow is the result of a development and acquisition program for a millimeter wave radar air/ground targeting system capable of being used in day or night, in adverse weather, and through battlefield obscurants.

The new Radar Electronics Unit (REU) offers improved power ratios and built-in processor expansion growth. It offers the potential of integration of Future Combat Systems (FCS) Class IV Unmanned Aerial Vehicle control and a common tactical data link. In addition, it lowers maintenance and operations costs while achieving higher levels of reliability. Target data is digitally available through the data modem for real-time transfer to other platforms and command posts for target confirmation, rapid engagement, and reduced fratricide.

LONGBOW HELLFIRE Missile

The Hellfire missile is the primary 100-pound (45 kg) class air-to-ground precision weapon having multi-mission, multi-target precision-strike ability, and can be launched from multiple air, sea, and ground platforms, including the Predator drone. But the most common platform is the AH-64 Apache helicopter gunship, which can carry up to 16 of the missiles at once.

The LONGBOW HELLFIRE missile locks on targets before or after launch and has been used in Operation Enduring Freedom, Operation Iraqi Freedom and in a number of targeted killings of high-profile individuals.

The Longbow fire-and-forget missile allows the Apache to launch from a shielded location and in adverse weather and battlefield obscurants, increasing aircrew survivability. The missile can lock on to a target before or after launch and has been extensively tested against multiple countermeasures. Its unique Doppler beam-sharpening technology significantly enhances the probability of mission success.

The LONGBOW system employs fire-and-forget LONGBOW HELLFIRE AGM-114L air-to-surface missile which has a millimeter wave seeker which allows the missile to perform in full fire and forget mode. It also works in adverse weather and battlefield obscurants, such as smoke and fog which can mask the position of a target or prevent a designating laser from forming a detectable reflection.

Boeing AGM-114D Longbow Hellfire Range weighs 47 kilograms (104 lb), including the 9 kilograms (20 lb) warhead, and has a range of 8km to 12km. The Hellfire Air-to-Ground Missile System (AGMS) provides heavy anti-armor capability for attack helicopters. For antiarmor roles, the AGM-114 missile has a conical shaped charge warhead with a copper liner cone that forms the jet that provides armor penetration. This high explosive, antitank warhead is effective against various types of armor including applique and reactive. Actual penetration performance is classified. It can also be employed against concrete bunkers and similar fortifications.

U.S. Army’s Modernized Target Acquisition Designation Sight/Pilot Night Vision Sensor (M-TADS/PNVS) system, is an advanced electro-optical fire control system that Apache helicopter pilots use for safe flight both day and night, and during bad weather. M-TADS /PNVS system also known as Arrowhead provides target data for the handover.

TADS/PNVS features both day and night sensor assemblies. The new advanced targeting FLIR sensor uses SADA 1technology and has three fields-of-view, a multi-target tracker, multiple-code laser spot tracking and internal boresight. A charge-coupled device camera improves day TV viewing, and the TADS electronic display and control unit (TEDAC) cockpit panel improves target resolution, situational awareness and survivable space for the air crew.

Upgradation Programs

Longbow was awarded a $103 million contract for Fire Control Radar Mast Mounted Assembly (MMA) Refurbishment program for the United Kingdom in support of the International Apache Attack Helicopter Project Office at Redstone Arsenal, Alabama. The data link enabled fire control radar (DLE FCR) is integrated into the MMA on the Apache, allowing pilots to accomplish multiple mission requirements while providing battlefield intelligence, surveillance and reconnaissance.

DLE FCR allows Apache aircrews to receive real-time video and map data from Unmanned Aerial Systems (UAS) and other manned airborne platforms with downlink sensors. Pilots are able to select the frequency of a specific UAS with the desired view and stream information to their multifunction cockpit displays. They can also enter UAS target data to cue Apache sensors and weapons. DLE FCR enables two-way communication between manned aircraft and ground station or between multiple manned aircraft.

The US Army earlier contracted Longbow, a joint venture between Lockheed Martin and Northrop Grumman, to upgrade its Apache attack helicopter fire control radar (FCR) systems. Under the $89.8m contract, Longbow will produce 84 radar electronics units (REUs) and software upgrades. The Longbow fire control radar’s electronics units reduce the size, weight and power requirements of the system by replacing two electronics boxes. The upgrades will increase the processing capability of the radar to support new software features in development.

The new LONGBOW Block III FCR REU provides reduced size, weight, maintenance and power requirements of the radar system. The LONGBOW Block III UTA provides a two-way, high-bandwidth data link, enabling aircrews to control Unmanned Aircraft Systems’ (UAS) flight path, sensors and lasers at long ranges. The system also provides the ability to receive high-quality UAS imagery on displays.