Unmanned Systems Technology 005 | Selex ES Falco UAV | Sense and avoid systems | RCV Engines DF70 | DSEI show report | Fuel cells | CUAV Expo, InterDrone and CUAV Show reports | SLAM

27 Selex ES Falco UAV | Dossier absorbers for each of the two under-wing legs and the single front leg wheels, is considered a small price to pay for protecting the highest value items on board. Even a semi-prepared airstrip is useable for take-off and landing given the sophistication of Falco’s landing gear, which also incorporates pneumatic tyres. The central location of the parachute bay means that when it is controlling a landing (normally only in the case of an emergency) the underwing wheels will tend to contact the ground ahead of the nose wheel for a stable touchdown. Design process Design of the Falco began in 2000. Selex ES used wind tunnels in Milan and Turin to assist initial design studies, correlating with its in-house CFD work. That CFD work was cross-checked with the wind tunnel and vice versa. The CFD work started with relatively simple software (in-house developed programs using formulations such as vortex lattice and panel solvers coupled to viscous 2D boundary layer algorithms). It then progressed through increasingly powerful tools (3D Panels, Euler and full Navier-Stokes solvers), demonstrating good correlation with wind tunnel tests and providing a deep insight into the phenomena observed during experiments and, later, full-scale flight trials. There was an initial wind tunnel study into the wing section geometry, then a study of the wing body as a complete item and finally a study of the entire craft with payloads and all other items that cause parasitic drag. Tests included the use of flow visualisation through the use of coloured surface oils, tufts and smoke injected into the airstream. All in all, the study was very time-consuming; the pay- off was excellent aerodynamics. Payload A typical Falco payload consists of imaging sensors plus radar. Its standard imaging system uses an electro-optical/ infrared sensor and offers the possibility of zooming the lens. As standard, the Falco also uses Selex ES’ PicoSAR radar. All-weather surveillance is possible using radar as opposed to camera imagery. PicoSAR is a compact, lightweight airborne ground surveillance radar system. It is an active electronically scanned array (AESA) rather than a traditional fixed-plate system. Selex ES says the key to PicoSAR is the use of AESA technology in a small, compact configuration, adding that “using many low-power, solid-state transmit/receive modules within its array, the PicoSAR radar is more reliable than conventional radar systems”. PicoSAR can be mounted directly onto the Falco platform and the beam steered electronically, or it can be mounted on a gimbal for an even greater field of view. It delivers high-resolution synthetic aperture radar imaging with a ground moving target indication capability. It is that which gives the Falco its all-weather ground mapping and surveillance capability. PicoSAR’s frequency is X-band. Its scan coverage is about 45º, and its maximum range is about 20 km. Often the Falco’s payload will give it a multimode radar capability, such as Selex ES’ Gabbiano. This means not only long-range air to ground (PicoSAR) but also air to air and air to sea, both with the capability to classify other craft from their signatures, plus a navigation mode, including a weather avoidance capability. The Gabbiano radar family provides an efficient, mechanically scanned, X-band solution for surveillance over land, along coasts and on sea in all weather conditions. In addition to standard air-to-surface search modes, it offers high resolution ISAR (Inverse Synthetic Aperture Radar) modes. These provide automatic target feature extraction, allowing the early classification of intercepted targets during missions at sea. The Synthetic Aperture Radar (SAR) mode provides a high-resolution imaging and mapping capability over wide areas. Other modes include Sea Moving Target Indicator (SMTI) and Ground Moving Target Indicator (GMTI), which support the detection of moving targets at sea and on the ground respectively. Ground mapping, weather modes (compliant with civil regulation requirements), all standard beacon modes and terrain avoidance modes provide effective navigation aids and Unmanned Systems Technology | Dec 2015/Jan 2016 The Falco under construction at Selex ES