Digital Raven Enhanced with New Gimbaled Payload, Image Processing

RQ-11B Raven small UAS fitted with the Mantis gimballed EO Payload
RQ-11B Raven small UAS fitted with the Mantis gimballed EO Payload. Photo: Aerovironment
Following the 'digital upgrade', Ravens are open for more enhancements. Photo: US Army

The Raven small Unmanned Aerial System (SUAS) has become a popular intelligence, surveillance and reconnaissance asset supporting low echelon formations (battalion and below). The Raven won its popularity due to the system’s simplicity and reliability as the manufacturer, Aerovironment Inc. (AV) developed the system to be used and operated by soldiers, in the field – simple, robust and effective. One of the unique features of the Raven, as well as other small and Micro UAS from AV is the use of fixed cameras staring forward and sideways, offering the user simple means to focus on the mission and on the target. For those who want more from their Ravens, AV is now offering a new gimbaled payload enabling the operator to keep the target in sight regardless of the aircraft attitude or flight path. AV unveiled the new payload today at the Army Aviation Association of America Annual Professional Forum and Exposition.

The modular payload is a member of AV’s Mantis family of gimbaled, micro multi-sensor payloads. It comes with a high-resolution color and an infrared thermal video sensor, as well as a laser illuminator (pointer), all integrated into a multi-axis sphere capable of continuous pan. The new gyro-stabilized payload will become a standard component of future Raven systems. AV also plans to offer it as an upgrade for previously fielded units. According to AV, upgrading existing digital Raven systems to accommodate the new payload requires only a software update to each air vehicle and ground control station.

The new payload is one of four products offered in AeroVironment’s “Mantis” suite of gyro stabilized, gimbaled sensor payloads now available for commercial applications including unmanned aircraft systems, manned aircraft, ground vehicles and watercraft. Designated Mantis i23, the new payload fits under the Raven’s nose, it measures 3.1 inches in diameter and weighs only 450 grams (16 oz). It packs a 5 megapixel daylight camera and 640×480 bolometric (uncooled) IR thermal camera with four zoom levels. The payload uses two levels of stabilization – electro-mechanical (gyro) and electronic (image stabilization).

The gimbaled payload doesn’t come cheap. At a price range of $48,000 – $30,000 (depending on quantity), the i23 costs almost as the whole Raven. However, at these rates, it is still relatively cheap, compared to larger and heavier multi-sensor payloads available on the market.

The value of the gimbaled sensor payload is not measures only in dollars, as it enhances the Raven capabilities by allowing a higher level of visual fidelity and continuous observation of an item of interest, regardless of the air vehicle’s flight direction. Furthermore, the new payload replaces two separate Raven system payloads previously required for day and night operation, one containing a stationary electro-optical sensor, the other a stationary infrared sensor. Flight algorithms allow the air vehicle to manage its own flight path based on what the user wants to see, rather than requiring the user to control both the air vehicle and the sensor separately.

“Our new mini-gimbal payload significantly increases the Raven system’s capability and can be quickly and easily integrated into the thousands of digitally enabled air vehicles already deployed,” said Tom Herring, AeroVironment senior vice president and general manager of its Unmanned Aircraft Systems business segment. Integrating the new gimbaled sensor payload marks the fourth upgrade to the Raven system since its introduction in 2003 and follows the successful introduction of AeroVironment’s digital data link (DDL) to replace the Raven system’s original analog communication modules.

Kestrel moving target indication software processes MTI tracks from the Raven's digital video from live or recorded clips. Photo: Sentinent.

Another innovation offered for AV’s small UAS, including the Raven is the Kestrel Moving Target Indication (MTI) package developed by the Australian company Sentinent. The software package is now available through AV, offering Raven, Puma or wasp III operators to automatically detect moving objects viewed through electro optical (VIS or IR) full motion video. Kestrel is integrated in the AV Common Ground Control System serving AV’s SUAS processing the video received from the drone to automatic extract motion detection and geo-location of detected tracks. The new application increases SUAS mission efficiency, by expanding area coverage and providing real-time and forensic operation support.

In February 2012 AV secured the exclusive, global distribution rights of Sentinent’s Kestrel software and is now integrating the system with its SUAS systems.

According to Herring this software makes it much easier to detect and track multiple moving objects in the battle space, thus delivering improved situational awareness to the system operator and tactical commander. “Kestrel Land MTI is deployed in a variety of theaters all over the world,” Simon Olsen, sales and marketing manager at Sentient added, “The automated cueing capability has proven to be a decisive edge in a number of operational missions. This extensive operational experience was a key prerequisite for this relationship to proceed.”

The Mantis i23 miniature payload fitted on the Aerovironment RQ-11B Raven. This 450 gram miniature payload packs a 5 mp digital video camera, a 640x480 uncooled thermal imager and laser pointer. Photo: AerovironmentI