Saab has sold more than 20 AEW&C systems to eight customers, a respectable share of a small but lucrative market (the UAE deal for two GlobalEyes and upgrades to two Saab 340AEWs was worth US$1.27 billion). The core of the system, the EriEye radar, started development more than 30 years ago. Although it has been upgraded continuously, it was time for a revamp.

The EriEye Extended Range (ER) on the GlobalEye looks like the original, with a dual-sided, air-cooled active electronically scanned array (AESA) operating in the S-band, but the hardware is all new, from the power supply through the transmit-receive modules and receiver-exciter to the processor.

The new radar is already running in rooftop tests at Saab’s Gothenburg site, and the first Global 6000 platform for the UAE is due to arrive in Linköping “shortly” for the start of modifications. The system is due for delivery in 2019.

Two years ago, Saab pulled a rabbit out of its hat by announcing that it was on the way to delivering the first production AESA radar based on gallium nitride (GaN) radio-frequency components, the land-mobile Giraffe 4A. GaN radar modules beat gallium arsenide (GaAs) in many ways, but chiefly they are more efficient (so they can produce more power without overheating) and have a wider bandwidth (good for jamming resistance) and lower noise.

That last attribute is important to Saab’s radar development. When Saab unveiled the Giraffe 4A, engineers touted the “purity” of the new radar’s signal – a measure of how much of the energy is concentrated at the nominal wavelength. With a high-purity signal it is possible to measure very small Doppler shifts and pull smaller echoes out of clutter. The radar can detect targets with very small radar-cross section (RCS) measurements, such as micro-drones and stealthy aircraft.

Other counter-stealth technologies in Saab’s new radars include “multiple hypothesis” tracking, in which weak and ambiguous tracks are analyzed over time, and either declared or discarded based on their behavior.

In fact, the EriEye ER’s name is a bit of a misnomer. Like any powerful AEW&C radar, the EriEye can see conventional aircraft at normal cruise altitudes all the way to its radar horizon. The new version restores its range against stealthy targets, against which it offers a 70% range increase or “the same range, against a target one-tenth the size,” a Saab engineer says. “That was a major criterion in the design”

The radar also works better against small and relatively slow surface targets, which becomes more important when combined with the GlobalEye’s signals intelligence (Sigint) suite. Rather than simply being an AEW&C aircraft, it can surveil the entire area – sea, littoral and air – with radar, fused with a Sigint picture. The aircraft can also carry a belly-mounted, 360 deg.-scan X-band radar – an option selected by the UAE – to add to the surface picture.

In the early 2000s, Israel took a different approach to multi-spectral surveillance, developing separate AEW&C, Sigint and ground-surveillance systems, mounting them on a common platform and netting them together via a single datalink to a central ground command and control system.

Saab’s “swing role” philosophy is different: according to Micael Johansson, head of the company’s electronic defense business, the high performance of the Global 6000 platform allows it to carry multiple sensors, quickly reposition itself to make optimum use of its sensors for dedicated missions, and still offer long endurance – up to 11 hours – at a long distance from its base. For instance, in a counter-drug mission, GlobalEye can maintain an air picture and a sea picture and monitor a transfer taking place onshore.

That in turn could mean a bigger AEW&C market. Some customers, Saab believes, see the advantage of AEW&C but can’t commit that kind of money for a single-mission system. Says Johansson: “With an AEW that has swing-role flexibility, we can capture customers that might be hesitant.”