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December 10, 2012
David Fulghum Ashdod, Israel
Some of the mystery ingredients of Israel's potent aerial strike forces are embedded in variants of the Gulfstream G550—darling of the business jet set—that are modified by Israel Aerospace Industries into military special-missions aircraft.
Versions of these compare roughly to the U.S. Air Force's RC-135 Rivet Joint (signals and communications intelligence), E-8B Joint Stars (radar ground surveillance) and the E-3 AWACS (air-to-air surveillance). But there also are some interesting differences. The sensor combinations are being shifted and expanded, data is being transferred and networked through protected communications links, and multi-spectral fusion is creating a real-time targeting and command capability. Such changes have become increasingly important as enemy forces have become smaller, faster and more lethal since the beginning of the Second Intafada in 2000.
First in the portfolio is the special electronics mission aircraft (SEMA) and airborne command-and-control post. The Israeli air force (IAF) has three of the aircraft operational, according to open sources.
The IAF describes the SEMA design as"battle-proven," which likely means it has been operationally active in the campaigns against Hezbollah in Lebanon and Hamas in Gaza, as well as the mysterious 2007 attack on the Syrian nuclear reactor and the raid on a Sudanese arms production and storage site earlier this year.
IAF officials asked IAI to compress signals, communications and other intelligence-collection capabilities into more-efficient airframes. The need was for smaller, cheaper, higher-performance aircraft that require less power and cooling for extensive electronic payloads, said Gideon Landa, General manager of Elta's Airborne Systems and Radars Div., earlier this year.
"The G550 became available and Elta made a very capable sensor suite that was compact enough to fit in it," he says.
The aircraft have electronic and communications intelligence-gathering packages and secure, advanced communications. It also functions as a command-and-control post that can conduct strike and intelligence-gathering missions far from Israel.
SEMA can operate independently anywhere in the world. Monitoring air defenses and military command and control communications in the Middle East is a far less demanding mission. The SEMA offers advantages that the Boeing 707 family was never able to provide to intelligence operations—speed, altitude (for a better electronic horizon), unrefueled range and long-range, hard-to-intercept communications. The aircraft's operational altitude is about 50,000 ft. and the radar and sigint horizon is about 250 nm. However, that range is conservative and probably limited only by the curvature of the Earth.
"If you are monitoring a target from 200 nm away, you don't have to use self-protection," Landa says. "If you want more detail from [directly over] the battlefield, you can also use unmanned aircraft carrying surveillance payloads."
Because of the advanced sensors and the expanded data-processing power on board, much of the detailed information is quickly available to SEMA aircrews. In addition, more than one SEMA can operate in a networked and synchronized formation to develop electronic orders of battle at much higher speed than single platforms. That capability has been tested during IAF training exercises in Greece and Italy.
"Even on a small platform you can do processing and use low-probability-of-intercept communications for a quiet, mobile network," says Gad Cohen, IAI's vice president for aviation and aerospace.
In addition, using "the advanced communications on board, we can operate most of the systems from the ground," Landa says. "So, we can carry more equipment and 10-12 signals intelligence and command-and-control guys. At the same time, it can be used by up to 30 operators on the ground."
Carrying fewer crewmen and more fuel translates to more time on station—up to 10 hr. unrefueled. SEMA is not designed for electronic attack, nor does it yet carry an electronic warfare suite, despite the fact that Elta has an impressive portfolio of electronic warfare systems.
"Our systems are decision-support —gathering information, creating theater awareness and providing tools to commanders," says Baruch Reshef, deputy director of group marketing for Elta. "We're in the area of fire control and not weapons. HPM [high-powered micowave weapons] is not our niche."
The next aircraft in the family is the conformal airborne early warning (CAEW) platform. Two are operational with the IAF.
"There was a huge hesitation in the military," Landa says. "They questioned how we could put a 20-ft. antenna on something as small as the G550, supply the power and cooling and still have it [cruise operationally] at 41,000 ft. But we did it."
"This variant is more like the Joint Stars," Landa says. "We have several solutions on different platforms that are not yet fully operational. Some are in full-scale development and production, others are in initial development."
One of the designs is called the multi-mission airborne reconnaissance and surveillance system (MARS2). Its capabilities include a very sophisticated synthetic aperture radar (SAR) and ground moving target indicator (GMTI). The payload also can include elint and comint as well as advanced communications and data links.
One of the benefits of integrating simultaneous radar, communications and signals intelligence onboard is that electronic emitters and other targets can be detected, identified and mapped with great precision, and the enemy's electronic order of battle can be monitored. Moreover, the addition of high-volume processing for SAR/GMTI means enhanced real-time intelligence exploitation. There can be up to four extra people on board for decision-making and tasking of other forces.
"So not only do we know what the bad guys are talking about, we know where they are located," Landa says.
Part of the enemy's visibility comes from the detailed intelligence sent from the midst of the battlefield by unmanned aircraft and pods on manned strike aircraft.
"We don't care what is manned and unmanned or what is strategic, standoff or stand-in, as long as they have our sensors onboard and share information via a networked infrastructure," Landa says. "All those aircraft are linked by network-centric solutions. Then data-sharing is seamless."
Because the aircraft can operate independently by using protected data links, it is less vulnerable to some kinds of electronic attack and cyberintrusions.
"We are using a variety of data links," Landa says. "What we typically fly on our multi-mission aircraft are dedicated line-of-sight data links for air-to-air and air-to-ground communications. They are typically wide band to handle the bulk of the information relayed to the ground forces, ships or ground centers. It is quite safe [from intrusion or detection] because it is narrow beam. Secondly, we also use non-line-of-sight datalinks—UHF, VHF and HF—which are more narrow band, but very long-distance."
Yet another available option is satellite communications that provide tactical data link networks. This capability also is designed and developed by Elta.
A limitation to the system could be the transfer of large, wide-area, high-resolution, synthetic aperture radar maps and electro-optical images. A way to address that bottleneck is to put four to six operators onboard the aircraft for imagery exploitation, so that the mass of data does not have to be transmitted from the aircraft. Part of the map is assigned to an intelligence expert onboard who knows virtually every stone of the area he or she is assigned to analyze.
Moreover, improved data processing and analytical tools are on the way from Elta's research and development centers. For example, as new radar technology is developed, it can be blended with signals intelligence, communications and electronic warfare capabilities.
Aircrews want to "keep in touch with the area they are scanning all the time," Landa says. "We call it persistent coverage or staring radar. In order to cover that much, we want a narrow beam to provide as much power as possible to an area of interest. You need to concentrate energy. As the field of view becomes narrow, the resolution and accuracy become better."
Another advantage to the narrow beam is that it is difficult to intercept and exploit. But to cover the necessary area at least to some degree, there needs to be a multi-beam radar with each beam operating as a separate radar with its own signal and radar processor.
"Many' means hundreds or even thousands," Landa says. "We call it new-generation multi-mode AESA radar. We start with an antenna that has many transmitting and receiving elements. The computer can manipulate the data infinitely, and the memory in the computer will pay attention to items of interest and continuously check them [for new or changing information]."
IAI also is looking at offering more unmanned options for the next generation of intelligence-gathering aircraft.
"More and more platforms will be UAVs," Reshef says. "Since they can't carry big payloads, there will be several working in parallel, all communicating to one central point that gathers the information and produces one combined picture of the theater we are working in."
