Stay Vigilant

Thales’ Vigile-D is already in service with the Royal Navy and will soon enter service with the Dutch and Portuguese navies promising a step change in ELINT collection.

Already in service with the Royal Navy, new deliveries of Thales’ Vigile-D naval electronic support measure are on the horizon.

Thales has told Armada Analysis that it will commence deliveries of its Vigile-D wideband digital Electronic Support Measure (ESM) to naval customers in the Middle East, and to the Dutch and Portuguese navies where it will equip several undisclosed vessels. While not confirmed by Thales, it is believed that these may include three examples of the ‘De Zeven Provinciën’ class frigates and the two frigates of the ‘Bartolomeu Dias’ class respectively within the next two years. Phil Ventress, the company’s head of strategy, product policy and marketing says that the Vigile-D is the “world’s first ever wideband digital receiver that is completely software defined.” He continues that the system is already in service onboard the Royal Navy’s Type-45 ‘Daring’ class anti-air warfare destroyers. Mr. Ventress argues that analogue receivers are no longer up to the challenge of operating in the current and future operating environments due to the growing saturation of the electromagnetic spectrum, providing a crowded environment in which radar transmissions can hide: Forthcoming fifth-generation cellular and wireless communications which will proliferate in the coming five-to-ten years will inhabit wavebands of 450 megahertz to five gigahertz, 5.925GHz to 7.150GHz and 24.250GHz to 52.600GHz. These same wavebands include L-band (1.215GHz to 1.4GHz), S-band (2.3GHz to 2.5GHz/2.7GHz to 3.7GHz) and C-band (5.25GHz to 5.925GHz) frequencies routinely used by naval surveillance radars and the K-band (24.05-24.25GHz) and Ka-band (33.4GHz to 36GHz) transmissions used by some anti-ship missile active radar homing seekers: “An analogue system is faced with saturation, and they can get desensitised in the electromagnetic environment,” says Mr. Ventress.

Thales’ specifications for the Vigile-D states that it covers a standard waveband of two gigahertz/GHz to 18GHz, although this is extendable downwards to 500 megahertz, and upwards to 40GHz. Direction of arrival accuracies of one degree are offered with a system sensitivity of at least 65 decibel-milliwatts as standard with higher sensitivities available on request. In terms of signal analysis, the Vigile-D can crunch up to two million pulses-per-second, with a frequency accuracy of 0.1 megahertz and a time accuracy of 25 nanoseconds. Regarding performance, Mr. Ventress says that the Vigile-D offers 0.5 gigahertz/GHz to 40GHz of instantaneous bandwidth, continuing that the system does not need to scan to discern signals of interest: “We sample right at the front end of the antenna, and we use four interferometers and antennas for our bearing accuracy.” He continues that the product’s “secret sauce” is its signals intelligence processing. This, Mr. Ventress says, allows it to detect radars employing low probability of interception/detection waveforms even in electromagnetically congested environments.

Mr. Ventress stresses that much thought has gone into how the system displays Electronic Intelligence (ELINT). Traditionally, electronic warfare practitioners see their ELINT displayed in a parametric fashion, detailing the radar’s characteristics. He stated that the company is keen to move away from this purely parametric approach, instead displaying ELINT in the form of a recognised electronic picture. This would be in a similar fashion to how a radar generates a recognised air or maritime picture. In this way the location of emitters can be clearly seen alongside their parameters. This approach, he added, would allow ELINT to be fused with other intelligence including data received from the Automatic Identification System transmitted across a waveband of 161.975MHz to 162.025MHz by all vessels displacing over 600 tonnes as per International Maritime Organisation regulations. Similarly data from ADS-B (Automatic Dependent Surveillance-Broadcast) air traffic control transponders carried by aircraft transmitting on frequencies of 978MHz and 1090MHz could be overlaid onto the ELINT. This would result in a richer tactical picture not only for the EW practitioner, but for the crew in general: “We’ve never been about purely parametrics,” Mr. Ventress says: “We’re about platform identification.”

Over the longer term, Mr. Ventress and his colleagues are examining ways in which artificial intelligence and machine learning could help naval ELINT systems interpret the deluge of data they will receive as the spectrum becomes ever-more saturated: “We are bringing in artificial intelligence techniques to crunch the data on behalf of the operator. Let the machine do the hard work and analyse the parametrics.” This could help the machine to provide ever-more accurate identification information, possibly moving towards the self-generation of emitter libraries. The advent of such technology maybe sooner rather than later, he states: “We are not that far away, and we could be seeing this within the next five-to-ten years, or even sooner.”

by Dr. Thomas Withington