Euronaval 2024 – Warning, hailing, and suppressing: Safran DSI LROI-COIL first international appearance
Military and paramilitary forces engaged in asymmetric operations often face situations where the threat is unclear, hence lethal fire might not be the appropriate answer. Safran Defense & Space Inc. (SDI), the US arm of Safran Electronics & Defense, developed a man portable laser system, the LROI-COIL, in service with the US military, which was seen for the first time outside the US at Euronaval 2024
For naval forces, a typical situation that is often characterised by a high degree of uncertainty is when small and fast boats approach a combat ship moored in front of a harbour or along a coast. In many cases using firepower might be excessive, especially if it turns out that the approaching vessel is not actually a real threat. To fulfil a US military requirement, SDI developed a man portable system, the Long Range Ocular Interrupter-Compact Ocular Interrupter Laser (LROI-COIL), which allows to escalate the response, and to determine the real intention of the approaching surface watercraft.
The LROI-COIL comes in the form of a binocular on steroids, with a mass of 4.6 kg; in the rear part we find the colour OLED two-eye display with a 600×800 pixels resolution that shows the image provided by the low-light monochrome TV sensor. On the front of the LROI-COIL we find on top two rows of 10 laser diodes each, while at the bottom on the left we find the LLTV lens, followed moving to the right by two series of lenses, each couple belonging to a laser rangefinder.
The 20 1W laser diodes provide a total output up to 26 W, emitting a Class 4 eye-safe green laser beam with a 520 nm wavelength, a 5 Hz output modulation with a 60 ms pulse width. In the hail/signal mode the central zone has a diameter of 10 metres at 2,700 metres distance while in the suppression/interdiction mode the diameter is reduced to 4 metres at 1,000 metres distance. The suppression irradiance is comprised between 100 and 2,500 µW/cm2. EDR On-Line understood that the output power is automatically trimmed by the system once the operator has selected the appropriate mode, the output power being regulated according to the mission and distance. The latter is provided by one of the two rangefinders, a Class 3R working on the 905 nm wavelength for short distances, and a Class1 operating on the 1,533 nm wavelength.
The LROI-COIL allows therefor to first hail and then warn, with minimal disturbance to the contact of interest, higher power bringing the intruder to renounce as it will be impossible to continue operating the vessel aiming at the target ship.
Of course, the LLTV channel, which is fitted with multiple zoom levels up to x4, can be used also for surveillance, inspection, and target acquisition. Apart from the image provided by the LLTV channel, the display also shows the visible laser illuminator reticle, as well as system information and messaging, including the battery status, power being provided by a Bren-Tronics BT70757BV Lithium-Ion rechargeable battery that ensures a one-hour continuous operation of the LROI-COIL, the system being of course used for much shorter periods at a time.
Safran Defense & Space Inc. is currently producing the system for the US Navy, around 200 units having already been delivered, now a special security agreement allowing the company to propose the system on the international market. Presented at Euronaval to answer specific naval requirements, the same system can obviously be used also by land forces for similar purposes.
Photos by P. Valpolini
