Electronic Combat Systems
Electronic Warfare includes any military action involving the use of electromagnetic and directed energy to control the electromagnetic spectrum or to attack the enemy. The three major subdivisions within electronic warfare are electronic attack, electronic protection and electronic warfare support. Electronic Countermeasures [ECM] is the element of electronic warfare involving actions taken to prevent or reduce an enemy's effective use of the electromagnetic spectrum. Externally mounted reprogrammable jammers provide protection for combat aircraft against both ground and airborne radar threats.
Electronic warfare/target sensing systems (EW/TSS) are those systems that include smart weapons, munitions, sensors, and processors that rely on signature data, such as electronic intelligence (ELINT), measurement and signature intelligence (MASINT), and other signature parametrics to identify specific targets or events. With the increased fielding of EW/TSS within the Services, a coordinated, integrated and synchronized process for the reprogramming of EW/TSS during joint task force (JTF) operations must be identified to maximize the effectiveness of these systems. Moreover, today's military operational planners must address the application of EW/TSS reprogramming within the framework of command and control warfare (C2W).
EW/TSS reprogramming provides the means to respond to changes in threat signature characteristics or unique theater signal environments, enhancing the capability and survivability of the joint force. Threat parametric signature changes occurring during contingency or combat operations may require operational decisions to change tactics, bypass or avoid the threat, reprogram EW/TSS against the threat, or target the threat for physical destruction. Reprogramming of EW/TSS provides a timely means to respond to immediate threat changes and correct system deficiencies or mitigate the impact of the threat change.
The reprogramming process starts with the collection and processing of intelligence data, progresses through assessment and engineering phases, and results in the distribution and loading of updated software and, in some instances, hardware/firmware. Reprogramming is integrated into operational plans through EW mission planning and the weaponeering phase of the targeting process. While reprogramming is generally an EW function on the Service component level, close coordination and deconfliction among the Service components in a JTF is done through the joint commander's electronic warfare staff (JCEWS). The staff coordination process begins with the interaction between the operations and intelligence staff directorate at the JTF and component level, because a signature parametric change may be identified as a result of the intelligence process or from operational mission reports.
The Joint Command and Control Warfare Center (JC2WC) has reprogramming oversight responsibilities for the joint staff. Oversight responsibilities include requirements to organize, manage, and exercise joint aspects of EW reprogramming and facilitates the exchange of data used in joint EW reprogramming. Although actual reprogramming of equipment is a Service responsibility, the coordination or reprogramming at the joint/combined level must occur because of the similarities in EW equipment. The CINC/JTF EW officer is responsible for facilitating the exchange of reprogramming data among the components.
The US military has recognized the increasing threat to its tactical aircraft from anti-aircraft infrared (IR) guided missiles. The lethality and proliferation of IR surface-to-air missiles (SAMS) was demonstrated during the Desert Storm conflict. Approximately 80% of U.S. fixed-wing aircraft losses in Desert Storm were from ground based Iraqi defensive systems using IR SAMS. Both IR SAMS and IR air-to-air missiles have seekers with improved Counter-Countermeasures (CCM) capabilities that seriously degrade the effectiveness of current expendable decoys.
Electronic Warfare like most defense-related technologies, felt the pinch of declining budgets in the early 1990s, but significant progress in the modernization of EW capabilities was still made, especially in the infrared area. Reductions included the retirement of the ASPJ, EF-111, and F-4G "Wild Weasel," and the termination of the EA-6B ADVCAP, F-15 PDF, and B-1B defensive systems.
The Suppression of Enemy Air Defense (SEAD) has borne the brunt of cutbacks with its loss of the EF-111, F-4G, and EA-6B ADVCAP. The loss of these assets or capabilities (for affordability reasons) constrains the warfighter's flexibility, but the warfighter will not be without a SEAD capability. The Joint Chiefs of Staff (JCS) investigated the non-lethal SEAD or support jamming area and concluded that the EA-6B, with the activation of additional aircraft, could perform the SEAD mission for both the US Air Force and the US Navy. Although there are performance differences between the EF-111 and EA-6B airframes (primarily range and endurance), EA-6B shortcomings can be ameliorated with proper mission planning and some additional support capabilities.
The retirement of the F-4G "Wild Weasel" has affected SEAD most. The lethal SEAD mission now rests solely on the shoulders of the F-16 Harm Targeting System (HTS). Although F-18s and EA-6Bs are HARM capable, the F-16 provides the ability to use the HARM in its most effective mode. The original concept called for teaming the F-15 Precision Direction Finding (PDF) and the F-16 HTS. Because this teaming concept is no longer feasible, the current approach calls for the improvement of the HTS capability. The improvement will come from the Joint Emitter Targeting System (JETS), which facilitates the use of HARM's most effective mode when launched from any JETS capable aircraft.
The Navy, as the lead service for the joint Integrated Defensive Electronic Countermeasure (IDECM) system, awarded an IDECM engineering and manufacturing development contract in 1996. The IDECM is the ASPJ replacement for the Navy's F-18E/F aircraft. The IDECM contains an RF subsystem consisting of an onboard techniques generator and a towed transmitter decoy. The techniques generator is actually a jammer receiver and processor. It is planned that this RF subsystem will have potential application on the B-1B as well as other platforms, such as the U-2 and TIER II+. The IDECM towed decoy also has application on the F-15.
The ASPJ, though terminated, has found use as a contingency asset. It is presently installed in F-18s and being used in the Bosnia operations area. Once it successfully completed the operational evaluation, by the end of 1996 it was installed in the F-14D using existing assets.
The Army has taken a significant step in modernizing helicopter survivability equipment with the introduction of the Advanced Threat Radar Jammer (ATRJ) and the recent award of the Advanced Threat Infrared Countermeasure (ATIRCM) system. The ATRJ is an integrated system with the jammer's receiver and processor also functioning as a radar warning device. This dual function negates the need for a separate radar warning receiver, which reduces future acquisition and support costs. The ATRJ has the capability to generate the more exotic countermeasure techniques needed to defeat the most sophisticated surface-to-air weapon systems.
One of the most revolutionary developments in electronic warfare is the ATIRCM system. Infrared countermeasures have moved towards laser-based jammers due to inherent tracking and pointing requirements. The ATIRCM functions include detection and cueing, tracking and pointing, and jamming. In operation, the system detects missile launch and decides if the missile is approaching the aircraft. If the missile is approaching, the system tracks the missile with enough accuracy to point a jamming laser at the missile seeker.
The front end of the ATIRCM system is a missile warning system. As the Army's ATIRCM approached an engineering and manufacturing milestone decision, the joint Air Force and Navy advanced missile warning program was proceeding toward a similar juncture. The respective service acquisition executives decided to merge the joint Air Force and Navy Common Missile Warning System (CMWS) for high performance tactical aircraft with the Army's ATIRCM program, thus creating the ATIRCM/CMWS program. The decision to merge the two programs stemmed from their similar system technical and timing requirements. Now, tactical aircraft and helicopters will have the same missile warning sensors and processor with different algorithms to account for different speed and altitude regimes. For the first time, real-time feedback of jammer effectiveness will be possible because ATIRCM tracks the missile. The Army has also taken integration a step further and plans to integrate its ATRJ and ATIRCM and merge with their onboard expendables dispenser.
When an aircraft has been detected, targeted, locked-on, and the missile fired, the emphasis has to shift to defeating the in-flight missile. Of course, except in the case of autonomously guided missiles, countermeasures against the ground (or hostile aircraft) tracking and command guidance system could still be effective (as in the case of conventional RF countermeasures). There are already have a number of countermeasures against RF seekers.
The real challenge is posed by the shoulder-launched "fire and forget" type of IR guided missiles. In most cases, such missiles require lock-on prior to launch; they do not have autonomous reacquisition capability. Given an adequate hemispheric missile warning system (such as that in development), it is quite conceivable that the missile can be defeated in flight. One approach is to use an RF weapon (directed from the aircraft under attack, or counter-launched) to defeat the guidance electronics. For optical or IR seekers that are obviously not "in-band" to the RF weapons, a "back-door" means of coupling the RF energy into the attacking missile must be used. Such back-door mechanisms exist; however, they are notoriously unpredictable and statistically diverse, differing by orders of magnitude from missile to missile, even those of the same class, depending on the missile's maintenance history.
Another approach is to use a laser to attack the threat in its seeker band. For highly dynamic aircraft that can maneuver to avoid the threat, it may suffice to simply blind the missile and assume it can be avoided. For slower, high-value aircraft (e.g., C-17, AWACS, JSTARS), blinding may not be sufficient; the threat could still glide in close enough to fuse and cause damage. In this case, it is possible to use a "smart" jammer, wherein the oncoming missile is first identified, and then a tailored in-band jamming signal is sent to cause break lock or actual deflection. Both the Naval Research Lab (for ship defense applications) and the Air Force Wright Laboratory are developing multiwavelength laser systems to accomplish this countermeasure. This technology is one step beyond the near-term ATIRCM system in that the laser waveform is tailored to the specific threat and hence will cover a wider class of missile seekers.
The infrared imaging missile seeker represents a leap in technology that may require more robust infrared countermeasures to defeat it, such as expendables that mimic an aircraft plume in several key ways. Resembling the aircraft to be protected would potentially defeat an IR tracker that may use several aircraft plume characteristics for tracking.
In 1994 the Joint Directors of Laboratories/Technology Panel for Electronic Warfare (JDL/TPEW) published the Tri-Service Infrared Countermeasures (IRCM) Techbase Master Plan. Under the sponsorship of OSD DDR&E, the services compiled a comprehensive plan with all the services' 6.2 through 6.3 IRCM programs, including the Advanced Research Projects Agency (ARPA) IRCM laser program. The plan took more than 2 years to complete and was the work of the EO/IR Countermeasures Committee members and the TPEW principals. What was needed was an integrated, single program that addressed the needs of all three services to protect helicopters, high performance tactical aircraft, and large transport vehicles. The main technology areas addressed were missile warning, expendables, multi-line laser sources, pointer trackers, band four fiber optic cable, and jamming waveforms. The plan was separated into near-, mid-, and long-term programs because of an urgent need to get countermeasures against some of the IR missile threats fielded and the need to focus the service technology teams. Each of the services was given specific areas of research, many of which were critical to the other services' technology demonstrators and advanced technology demonstrations (ATD). In addition to the threat to aircraft, the plan also addresses the IR anti-shipping missile threat and the IR top attack munition/antitank guided missile threat to ground vehicles.
The Partnership Process for EW Acquisition was commissioned in June 1995 by Darleen Druyun, the Acting Assistant Secretary of the Air Force (Acquisition), and Lt Gen Howard W. Leaf (USAF, Ret), the Director of Air Force Test and Evaluation. Lt Gen Ralph E. Eberhart, then the Air Force Deputy Chief of Staff for Plans and Operations, agreed to co-sponsor the effort in January 1996 and coined the term "Partnership Process." The Partnership members from the military Air Force, Navy, and industry EW community represented organizations with functional responsibilities across the gamut of EW acquisition (for example, acquisition, operations, logistics, requirements, test and evaluation, modeling and simulation).
The Partnership Process looks beyond technical specifications, to place the focus on system suitability/performance based on the concept of military worth to tactics and campaigns, then best solutions based on cost and schedule constraints. The Partnership Process has drawn on lessons learned from world-class companies to redesign the process of EW acquisition. The changes instituted by the Partnership provide great benefits to the EW community and the warfighter and should serve as the model for reforming other areas of acquisition.
Source:
FAS
