Falcon Edge IEWS

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EWmaster

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Unread post15 Jul 2005, 14:43

One of the most secretly held pieces of equipment in the new batch of block 60 F-16s seems to be the EW gear, aka Falcon Edge or IEWS (Integrated Electronic Warfare Suite). After an extensive search on the internet here is what I have found:

According to the Norhrop Grumman's Defensive Systems Division (DSD) website, Falcon Edge is "based on a revolutionary concept that leverages the latest radio frequency (RF) and digital technologies(...). Falcon Edge is comprised of two major subsystems: a passive receiver and an active jammer. Both systems utilize common technology that allows higher levels of subsystem interoperability. Falcon Edge features high sensitivity, wide-band digital receivers, and digitally based countermeasures".

That didn't satisfy me so the search went on. Why this system is so secretive? A paper entitled "Was the horse let out of the barn" of the National Defense Univeritie's War College give us a partial explanation: after comenting some aspects of the (then) proposed sale of Block 60s to the UAE the text says that the advanced EW system is "entirely internal, as opposed to the external pods carried by USAF F-16. The system incorporates classified digital technology that warns pilots of enemy radars while simultaneously sending out countermeasure signals, and will automatically dispense chaff and/or flares to decoy enemy radar or missiles. A significant capability is that it also provides the location of the threat emitter, rather than simply showing the direction the radar is comming from, to allow the pilot to attack it".

Another interesting source was, of course, Aviation Week. The only article I have found in this magazine that briefly deals with the B60's EW issues is the one published in March 13, 2000. Northrop Grumman DSD website says that Falcon Edge features an active jammer, but Aviation Week goes further and affirms that "the F-16 Block 60 being sold to the United Arab Emirates has the first radar counter-countermeasures system with an adaptive cross-polarization capability against coherent monopulse Doppler radars. That should allow it to defeat the most advanced surface-to-air missiles. In all, the EW system offers 11 new or updated technologies for foiling radars and radar-guided missiles".

Globalsecurity explains the last quote: "There are two types of cross polarization techniques used in modern EW systems, adaptive and non-adaptive. The new adaptive cross polarization system determines the polarization of the incoming signal and then retransmits the signal with an orthogonal (cross) polarization. Adaptive cross polarization is an improvement over non-adaptive since non-adaptive systems can only assume the polarization of the incoming signal and then retransmit a signal that is swept about the orthogonal of the assumed polarization."

With respect to the receiver portion of the advanced EW system, an article of Jane's IDR (International Defence Review/February, 2001) contains a short but interesting reference. It states that Northrop Grumman "has additionally developed the LR-105 RWR and precision targeting system for the F-16 Block 60. The LR-105 is a highly modified adaptation of the LR-100 electronic support measures (ESM) system, which combines the NexGen digital receiver chipset with Litton's patented Long Baseline Interferometer passive geolocation technology".

Finally, the former Journal of Electronic Defense (now eDefense) provides updated information on two articles:

"The Falcon Edge IEWS is a derivative of DSD's Tactical Radar Electronic Combat System (T-RECS), originally developed for use on unmanned aerial vehicles (UAVs), that features a brand new digital radar-warning receiver (RWR) and digitally based radio-frequency (RF) jammer" (May 10, 2005).

"In terms of avionics, the Block 60 looks more like a F/A-22 Raptor or F-35 Joint Strike Fighter (JSF) than any other F-16. The radar, electro-optical suite, EW system, mission computer, and cockpit displays represent the largest elements of the development program. Northrop Grumman (Baltimore, MD) provides the Block 60 sensors(...).

Also from Northrop Grumman (Rolling Meadows, IL) is the Falcon Edge EW system, which stems from research, begun in 1993, into low-cost, high-performance EW gear based on commercial off-the-shelf (COTS) technology. Some Falcon Edge components use the same Motorola (Tempe, AZ) processor as the Power Mac G4 and some of its signal-processing hardware uses chips from Internet-capable cell phones.

The Falcon Edge provides radar warning, jamming, and emitter targeting. As in the case of the F/A-22 and JSF, the passive EW system helps to locate and identify airborne and surface targets and can locate a surface target in distance as well as bearing. BAE Systems (Nashua, NH), which did not win the integrating contract for the EW system but provides precision direction-finding (PDF) antennas to Northrop Grumman, has stated that the Block 60 system was designed to "exceed existing system capabilities several-fold," including long- and short-baseline interferometry antennas used for target location.

The Falcon Edge includes a Raytheon (Goleta, CA) fiber-optic towed decoy (FOTD). Initial flight tests, focusing on endurance and aerodynamic stability, were completed successfully in December. According to Raytheon, this was the first demonstration of an FOTD in high-risk flight regimes, including high-G deployment and high-G maneuvers representing extremes of the F-16 flight envelope. Terma (Lystrup, Denmark) supplies the Block 60's expendable countermeasures, with extra dispensers in the weapon pylons.

The Block 60 avionics are coordinated by an Advanced Mission Computer (AMC) and a fiber-optic network, using COTS technology, supplied by Lockheed Martin's Naval Electronics & Surveillance Systems unit (Eagan, MN). The AMC was a late improvement to the Block 60, replacing the Ada-language-based MMC. Advantages include less reliance on unique components and the fact that it is much easier to hire programmers to work in C++ than in Ada." (August 1, 2003).


Any comments?
Last edited by EWmaster on 10 Mar 2006, 14:43, edited 14 times in total.
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EriktheF16462

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Unread post15 Jul 2005, 14:55

yeah admin delete the post and ban the poster if the FBI isn't already beatin on his door.
F16 462 AD USAF. Crew dog for 3 and Even a pointy head for a few months.
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Unread post15 Jul 2005, 15:28

Front View of the B60. Note the two pair of aligned antennas in both sides, directly behind the radome. These supposedly belongs to the IEWS.
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Obi_Offiah

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Unread post16 Jul 2005, 00:16

EriktheF-16462 wrote:yeah admin delete the post and ban the poster if the FBI isn't already beatin on his door.


Hi Erik

I can't really see a problem with the post. EWmaster has quoted open material in the public domain from established publishers has well as the manufacture. I'd expect thoughs in the know to stay away from this thread and others to speculate.

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Unread post16 Jul 2005, 00:22

Interesting information, to say at least! 8)
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16spec

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Unread post16 Jul 2005, 14:08

The system incorporates classified digital technology that warns pilots of enemy radars while simultaneously sending out countermeasure signals, and will automatically dispense chaff and/or flares to decoy enemy radar or missiles. A significant capability is that it also provides the location of the threat emitter, rather than simply showing the direction the radar is comming from, to allow the pilot to attack it".


Doesn't sound like anything new to me. They probably cut and paste that description from the Block 40 debut.
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Unread post16 Jul 2005, 15:21

16spec wrote:
Doesn't sound like anything new to me. They probably cut and paste that description from the Block 40 debut.


Threat azimuth is old news. Threat azimuth and range is something else entirely.

I'd love to know how they do it.
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Unread post16 Jul 2005, 15:39

PointyHead wrote:
16spec wrote:
Doesn't sound like anything new to me. They probably cut and paste that description from the Block 40 debut.


Threat azimuth is old news. Threat azimuth and range is something else entirely.

I'd love to know how they do it.


I think this has to do with the new digital RWR revolution thats about to happen, using methods such as PLAID or Precision Location and Identification. JED Online had a good article describing the technique back in 2000. I saved the article before the site became subscriber only, but there may be copyright issues with posting it here?.

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Unread post16 Jul 2005, 16:15

Hi Obi. Thanks for your clarification. Maybe PLAID is related to the IEWS. In the budget description for the USAF EW (fiscal year 2004), which you can find at:

www.globalsecurity.org/military/library ... 04270F.pdf

there is a mention of PLAID development:

"PLAID will improve situational aircrew awareness by providing accurate ground emitter location and unambiguous identification. Threat systems can disupt or negate operational missions, even wihtout firing, by requiring aircrew reactions that affect mission objectives. Improved threat information from a modernized Radar Warning Receiver will assist the aircrews in determining precise threat range/directions and provide option responses short of mission abort or violent aircraft maneuvering. Knowing threat location will help an aircrew respond 'real time' to threats by providing accurate information to allow the aircrews to reroute around hostile areas. PLAID will, where feasible, utilize existing aircraft RWR antennas and wiring (Group A hardware). Some modifications may be necessary to optimize geolocation performance and minimize electromagnetic interference. PLAID development is currently focused on the ALR-69 RWR but PLAID technology can also be applied to other RWRs. Aditional related enhancements to provide the capability to pass ground emitter target data (location, type, ID) to other system are under consideration."

NOTE: Could you transcribe here the eDefense (formerly JED) article has you mentioned? I'm very interested in all of the issues that surround advanced EW techniques and I have a lot of articles of JED too (I was very disappointed when its website went "closed"). I have seen numerous articles of numerous publications (AW&ST, Jane's, JED...) posted in various forums which contains subscribers-only information, so I think you can put it here.
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Unread post17 Jul 2005, 03:32

Threat azimuth is old news. Threat azimuth and range is something else entirely.

I'd love to know how they do it.


Block 40 and above ALR-56M equipt aircraft display both azimuth as well as approximate threat range on the azimuth indicator. Or are we talking about something different here?

Anyways yeah the rest of that sounds pretty interesting, very fancy to say the least.
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Unread post17 Jul 2005, 15:48

I have been thinking in all those digital RWR issues and my conlussion is that all of them, as mentioned by Obi Offiah, can be included into the digital RWR revolution. In fact, the F-22, described by Bill Sweetman as an antenna farm (it has 30 plus antennas smoothly blended into the wings and fuselage), has three types of analog receivers, but there are plans to reduce them to a broadband digital receiver (see Avionics Magazine "Air dominance with the F-22 raptor") as part as the widest Lot 5 modernization effort. Precission location of ground and airborne threats by ESM (Electronic Support Measures) is essential in the battlefield of the future. F-22's ESM, the ALR-94, can detect and track a target with very high accuracy, as far as 2º by 2º in azimuth and elevation. This is comparable as the best tactical SIGINT/jamming aircraft such as Prowler/Growler ICAP-III. This "almost SIGINT" capability will give future fighters and enormous advantage and the possibility of being employed in the SIGINT or jamming role with minmal modifications. F-16 block 60 belongs to this revolution, but the main difference between this fighter and the new stealth ones (F-22, F-35...) is that it has an advanced jamming system with is not present in the new generation of stealth aircraft that encompasses stealth above all.
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Unread post18 Jul 2005, 00:25

I too am an aircraft enthusiast, but....... I agree with Erik. I don't know where you got the pics of the F-22 schematics. They don't look like something you would see in magazine though. Anything that labels specific antenna and equipment locations (especially on a highly classified acft) should not be out. I don't know if you are in the military, but COMSEC is a huge deal. There is no reason that anybody, other than those involved, needs to know this information.

LOOSE LIPS SINK SHIPS!! I'm sure you've all heard that one before.
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Unread post18 Jul 2005, 01:05

Hi Taco. First of all, I'd like to say definitely that I dont work for the military or any of their contractors. There seems to be a little controversy with that in this forum. I am simply an aviation enthusiast who has searched almost every inch of the internet looking for the rarest and most cutting edge pieces of information. And in relation to the F-22 EW/CNI graphics, you can find them at www.aeronautics.ru/nws002/f22/systems.htm . Less conspiracy theories please!!
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Unread post18 Jul 2005, 12:21

Radar Warning Receivers: The Digital Revolution
by Dave Adamy

Radar warning receivers (RWRs) have been an important part of electronic warfare (EW) since the Vietnam War. They have been repeatedly upgraded to meet new threats, but they still look and work a lot like the original systems. The threats are still changing, causing the RWRs to change with them; but the main driver for change now is the increasingly complex tasks we want these systems to perform.

WHAT IS AN RWR?

An RWR is a specialized receiving system used to identify, locate and display threat radar signals very quickly. Although mostly associated with aircraft, RWRs also protect ships and ground-mobile assets. The RWR typically has an instantaneous 360° field of view and covers the whole radar-threat spectrum quickly enough to receive the first beam of a radar signal to reach the protected platform. Its processing only identifies known threat signals from a threat-parameter-identification table. It is optimized for rapid data throughput, collecting only enough data and performing only enough processing to identify the threat type unambiguously. It typically has enough sensitivity to receive main-beam transmissions and enough angle-of-arrival accuracy to support situational awareness in a cockpit and to hand off threats to a jammer.

The RWR must have a 100- percent probability of intercept (POI), or very nearly 100-percent POI, for all threat-signal types it is expected to encounter. POI in this case means the ability to receive and display a signal within a very short time (typically about one second) starting when the first energy (above the sensitivity threshold) from that signal reaches the location of the protected platform.

AN RWR IS NOT AN ESM SYSTEM (YET)

Fig 1 Most RWRs operate from four or more cavity-backed spiral (or similar) antennas with their boresights aimed symmetrically around the protected platform.

An electronic-support-measures (ESM) system is different from an RWR in that the ESM system typically has more sensitivity and greater location accuracy. However, the main difference is that an ESM system performs more detailed analysis on received signals. It will typically measure and record all of the signal parameters and may also have some sort of human intervention - making the ESM system closer to an electronics-intelligence (ELINT) system. It also typically has less than 100-percent POI (by the RWR definition). The ESM system typically receives threat signals in their side lobes, rather than requiring illumination from the main beams. It knows the location of threat emitters with enough accuracy to hand off that information to another platform or to support weapon targeting.

Cliff Moody of the Information Warfare Battle Lab (Kelly AFB, San Antonio, TX) expressed the opinion that RWR-system users want to convert RWRs to ESM systems while still retaining the RWR capability. This is a view shared by most of the leaders in the RWR field interviewed for this article. A recent study in the UK showed that the RWR function cannot be adequately performed by existing ESM systems, so the clear implication is that both RWR and ESM systems will require performance enhancements to perform both jobs. It seems very clear that no-one is willing to back off on RWR performance requirements to gain the additional ESM capabilities, since one hit from an unseen weapon can ruin your whole day.

NEW REQUIREMENTS

The changes in RWR requirements are driven by new threats, but more importantly from additional operational functionality that users would like to get from RWRs. The primary desired changes are as follows:
  1. enough sensitivity to receive all threats from their side-lobe effective radiated power (ERP), beyond the lethal range of the weapons they control;
  2. direction-finding (DF) accuracy adequate to hand off threat location to another friendly platform;
  3. determination of the number of pulse-Doppler radars present and discrimination of friendly emitters from enemy emitters;
  4. specific-emitter tracking (SET) or, preferably, specific-emitter identification (SEI); and
  5. detection and location of low- probability-of-intercept ( LPI ) radars.
NEW RWR TECHNIQUES

There are several important new techniques supporting basic changes in the way the RWR task is performed. They are discussed here in general technical terms.

PLAID is the Precision Location and Identification technique, in which precision measurements are made on signals received by normal RWR antennas. From collected amplitude and phase data, threat-signal parameters are measured to resolution two orders of magnitude better than in normal RWR processing. This is expected to support SET and SEI. Lt Col James Schoeneman, the acquisition management division chief for EW programs at the Air Force Materiel Command, observed, "PLAID's parametric resolution is adequate to 'see' the effect of a little 'ding' in an antenna."

By determining fine scale differences in the frequency of signals received by two antennas, PLAID will be able to calculate differential-Doppler (DD) contours, and from very accurate measurements of differences in the time of arrival of pulses at different antennas, it can calculate time-difference-of-arrival (TDOA) contours. These two sets of contours (which are perpendicular to each other at the emitter location) allow the precise calculation of emitter location even when the threat has emission control (i.e., variable ERP). It is anticipated that PLAID will be able to detect and process LPI modulations as well, although software enhancements will be required.

The PLAID approach includes an advanced digital receiver (ADR) with sufficient processing power to support modern algorithms for time- and frequency- domain analysis. The installation design requires that the ADR replace an existing RWR unit or that an existing unit be internally modified, but no A-kit modifications are anticipated.

PLAID has been flight tested on F-15 and C-130 aircraft and met all its objectives, including SEI and precision location. A competition is underway to select a supplier to provide this capability on the AN/ALR-69 RWR for the US Air Force.

PDID is the Pulse-Doppler Identification Module, a special analysis module to process pulse-Doppler (PD) signals from airborne fire-control radars. This is a digital processor subsystem that accepts video outputs from any RWR. It analyzes PD signals using the same techniques employed by the receivers in PD radars. The result of this analysis is the determination of the number of PD signals which are present and the identification of the specific radar types (i.e., friendly or enemy). The PDID module increases the sensitivity (against PD signals) of the RWR with which it is used by optimally filtering the received signals. Its algorithms analyze the fast Fourier transform (FFT) of the video from the RWR, extracting sufficient parametric discrimination to employ SEI techniques, thereby allowing SET throughout one or several missions. The results of the analysis are returned to the host RWR for display along with its other threat information.

PDID has been successfully demonstrated at the test range at Eglin AFB. It is designed for installation as an augmentation to any RWR or as a modification to an RWR. Since many RWR suppliers indicate that they are replacing computer boards in their processors with fewer boards, PDID is one of the upgrades that could fill that extra available space.

Les Wade of Condor Systems (San Jose, CA) summarized, "PDID is a quick-reaction, low-cost solution to a critical problem: the prevention of fratricide in air-to-air combat because of confusion of PD-emitter types."

Advanced Tactical Targeting Technology is a program to develop a multiple-aircraft threat- location approach. This depends on data links between tactical aircraft to share angle-of-arrival information. With angle of arrival information from multiple platforms, a processor can triangulate to determine threat-emitter location. When the collection platforms are separated by distances of the same order as the distance to the threat emitter, location accuracy is enhanced. Also, multiple measurements from multiple moving platforms allow the averaging of data to reduce the uncertainties caused by individual angular-measurement errors. Initially, the platform-to-platform links will be existing links, but eventually, laser-based datalinks are expected to be employed.

Sophisticated new software approaches are the flipside of the digital hardware enhancement. New algorithms and new approaches to optimizing system assets are under constant development by most of the RWR suppliers. Al Sock, Director of Advanced Technology at Sanders (Nashua, NH), explained, "A great deal of software sophistication goes into the optimum application of narrowband resources - for example, 'hypothesis testing' in which we hypothesize what the threat can do to optimize sensor management to improve response time with a priori and measurement knowledge." This is in addition to the new algorithms supporting functions like direct-signal analysis and precision emitter location. To this, Paul Westcott, chief of the Sensors Application and Demonstration Division at the Air Force Research Laboratory (Wright-Patterson AFB, OH), adds, "New systems will have open-system architectures with little if any proprietary software. This will optimize future software developments through unfettered competition in system upgrades."

LPI -SIGNAL DETECTION

Because of the nature of LPI -signal modulations, they cannot be detected by normal receivers. Detection and processing of these signals will require sophisticated digital receivers which can apply matched filtering and correlation techniques to collected signal data.

Menahem Oren, general manager of Elisra (Bene Beraq, Israel), believes that " LPI modulations cannot be properly processed with 'snap shots' of data. These signals will require the collection of continuous streams of data." We can collect and process all current threat signals with current receivers but will need digital receivers are needed to detect LPI signals.

NEW SOLUTIONS, NEW PROBLEMS

New solutions sometimes uncover new challenges to be overcome, as indicated by the following:
  1. Increased sensitivity allows the detection of emitters in their sidelobes, but on the other hand, it forces the receivers to receive (and deal with) a significantly increased numbers of signals. Each 1 dB of additional sensitivity increases the area in which signals of any given radiated power can be received by 25 percent.
  2. Increased numbers of signals increase the processing load. Increased processing power and memory will be required to deinterleave, prioritize and identify all received signals.
  3. Increased measurement fidelity means that more bits of data are produced. This requires more computing speed and more memory. Within single platforms, the explosion of digital capability handles this problem, but the transportation of this data is still challenging. Higher datalink bandwidths require higher carrier frequencies which are more line of sight and require antennas with narrower beams. Narrower beams require tighter antenna tracking - a problem between rapidly maneuvering platforms.
  4. Differential Doppler (DD) provides extremely accurate emitter location, but the measurement is based on frequency shifts caused by the velocity of the aircraft making the measurements. This causes no problem for ground emitters but a significant problem for airborne threat emitters: the velocity of airborne threats is of the same order as that of the protected aircraft, so the Doppler shifts caused by the two aircraft are difficult to separate. Although people in the business believe that this will yield to advanced processing algorithms, it remains a problem at the moment, limiting the usefulness of DD systems to ground-emitter location.
RWR HISTORY

Fig 2 The original RWR block diagram included four antennas, four crystal video receivers, a processor and dedicated controls and displays.

The original RWRs deployed early in the Vietnam War were designed to detect and locate a very number of threat-radar types. By the end of the war, we were already dealing with large threat libraries.

The classical RWR worked with a few (typically four) directional antennas (small cavity-backed spirals) located somewhat symmetrically around the aircraft, as shown in Fig 1 . The block diagram (see Fig 2 ) was simple and efficient. Signals from these antennas went to crystal video receivers covering the full threat-frequency range in bands selected by front-end filters. Video outputs from the crystal video receivers were passed to a processor unit, which analyzed the top-level parameters of the received pulse trains to determine the type of radar (and, hence, the type of weapon) and its operating mode. By comparing the amplitudes of the (usually four) inputs from the distributed antennas, the processor determined the angle of arrival relative to the nose of the aircraft. The range to the radar was estimated from the received signal power. The type of threat and its location relative to the aircraft were displayed to the aircrew. At first, the location was displayed as a series of strobes on a 3-in. cathode-ray tube (CRT). The angle of the strobe showed the direction of arrival, and the length of the strobe indicated (roughly) the distance to the threat (the longer the strobe, the closer the threat). The type of threat was indicated on a lighted display panel.

Later, the display showed synthetically generated strobes with coding for the general type of threat (plus the lighted panel). Then, the displays were changed to write a character on the CRT at the estimated location of the threat. The character identified the type of threat, so the aircrew could get the whole threat picture from the single screen display (which was still the 3-in. CRT).

Audio outputs have always been provided. At first, they were just stretched pulses, so a skilled operator could hear the pulse-repetition frequency and the scan pattern of threat radars. Later, this "raw video" audio output was replaced by synthetic audio for important audio warnings.

Recent RWRs look much like the original systems. They also contain many of the same components. The antennas are little changed (although dual-polarity antennas are in use with some systems), and most still have crystal video receivers. However, as shown in Fig 3 , most have additional receiver assets, either in the processor chassis or in a separate chassis. These include instantaneous-frequency-measurement receivers, narrowband superheterodyne receivers or channelized receivers. They often have band-stop filters to remove continuous-wave and PD signals from the crystal-video-receiver inputs, and most have a capability to insert new threat-parameter data rapidly. Some modern RWRs drive dedicated displays, and some input data to integrated displays, incorporating data from several subsystems.

EVERYTHING'S GOING DIGITAL

Fig 3 Modern RWRs typically have the assets of the original RWRs plus filtering and additional receiver assets.

The key to improvements in RWRs is clearly increased incorporation of modern digital technology. Most existing RWRs use computer chips much less capable than those in handheld computers - and are precluded from upgrading by configuration control - while commercially available components are coming down in price and doubling their processing speed and memory with shocking regularity. As pointed out by Lynn Gahagan of Litton's Advanced Systems Division (College Park, MD), "For the first time, our [computer] capability exceeds our need." This is a shocking change in an industry that has always had to scratch and claw at the limits of the state of the art to meet our operational needs in life-and-death situations.

Since the addition of new units to a platform require expensive A-kit changes, most of the approaches to adding digital capability to RWRs involves replacing processing boards within the units. The increased capability of modern processing chips allows vastly increased processing power on fewer boards, meaning that the modified unit will have more computing power to do the existing tasks better and spare card slots to add even more capability. Increased processing capability will allow the integration of advanced processing algorithms, the rapid analysis of greater amounts of data in real time, and the incorporation of digital receivers.

Although an RWR cannot perform the same functions as an ESM system, the two can be integrated, as illustrated by the AN/ALR-76/504 (shown here). (Lockheed Martin photo)

According to Frank Bauman, Litton's PLAID program manager, everyone is trying to "move the digital world closer to the antenna, because the cost of RF hardware is going up and the supply is going down, while digital processors are going the other direction." He added, "The digital chips from the industrial world are clearly increasing capability and reliability while reducing cost." Jacques Draperi of Thomson-CSF Detexis (Paris, France) reinforced this, explaining that adequate sensitivity and accuracy can be achieved today by selection of appropriate narrowband and wideband receivers, but that, in the future, digital receivers will clearly be required.

Digital receivers are being planned for virtually all RWR- upgrade programs. A digital receiver comprises an analog-to-digital converter (ADC), which digitizes RF signals. FFTs are then applied to the digitized signals to change them into the frequency domain. The resolution cells in the FFT can be set to optimize the effective bandwidth for individual signal types or processing tasks, thus improving intercept sensitivity. Because the modern ADC provides very high sampling rates and quantizing ratios, the signal data has enough character to allow sophisticated analysis of signals for specific emitter identification. Westcott noted, "Digital-receiver technology will allow us to measure frequency to tens of Hertz and time to sub-nanoseconds." This technology also allows correlation functions to be performed for the analysis of digital-signal modulations, including those applied for LPI purposes.

The venerable RWR will be with us for the foreseeable future, and it will probably look much the same. However, with all of the new requirements being thrustupon it, the internal hardware - and even more the embedded software - will have a whole new look and a whole new way of doing a whole new job.

Source: This article was posted at JED Online (now Edefence Online) in June 2000
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Unread post18 Jul 2005, 12:40

Just for your information:

The graphics were initially published in the old Lockheed-martin website around 1999-2000 (when it actually contained information), under the f-22 media package section.

They were also reproduced in the F-22 book published by Aviation Week.
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