Unmanned Systems Technology 015 | Martin UAV V-Bat | William Sachiti | Sonar Systems | USVs | Desert Aircraft DA150 EFI | SeaCat AUV/ROV | Gimbals

65 2022 broadband/wideband multi-beam echo sounder, a sensor whose 60 kHz bandwidth is claimed to provide twice the resolution of other commercial sonars in terms of data accuracy and imagery. The system’s range is 500 m with a claimed range resolution of 1.25 cm at all frequencies. R2 Sonic quotes a ping rate of 60 Hz and pulse lengths of between 15 and 1115 μs. The Sub Bottom Head is designed to provide a clear view of what lies under sediment during archaeological, geological and military tasks using a Tritech dual-frequency SeaKing parametric sub-bottom profiler. While its 200 kHz primary frequency profiles the seabed, the transducer’s multi-element composite design enables the echo sounder to emit much lower frequencies while minimising the unit’s overall size. With a 20 kHz pulse, it penetrates the seabed and highlights structural differences that conventional echo sounders cannot reveal, according to Tritech, showing buried objects and layers in the sediments. Tritech Seanet Pro software enables quick visualisation of results, allowing the operator to choose the 200 kHz seabed image or the 20 kHz sub-bottom view, or both at the same time. The Geo-Magnetic Head is designed to detect metal objects under sediment. It includes a cable intake, a towed Geometrics G-882 caesium vapour marine magnetometer and a cable guidance system. Designed for professional surveys in deep or shallow water, the G-882 produces a digital output that can be recorded with any serial data logger, says Atlas. Survey Head Four combines the capabilities and sensors of Survey Head One and the Sub Bottom Head, and adds a connecting port for a G-882 magnetometer. The Water Quality Head integrates a Sea and Sun CTD 90 water condition monitor that contains sensors for pH, conductivity, salinity, dissolved oxygen, temperature, pressure, turbidity and chlorophyll. It is also fitted with an enviroFlu-HC hydrocarbon sensor, microFlu coloured dissolved organic matter sensor and a Ramses photosynthetically active radiation irradiance sensor, all from TriOS. Developed for operator-controlled inspection of objects, the Inspection Head contains a forward-looking multi-beam sonar and a pan/tilt camera. The Tunnel Inspection Head contains five cameras for a 360° view, and has LED lighting. The wide video graphics array cameras are based on 752 x 480-element chips, while the low-light camera can generate usable images down to 0.5 lux. Dedicated guidance software in the head controls the SeaCat via what is called the ‘backseat driver’ interface. Designed for inspecting man-made underwater infrastructure and ship hulls, the Harbour Inspection Head contains a 3D video camera and a BlueView MB2250-45 high-frequency multi-beam echo sounder. Finally, the Custom Head option allows a customer to commission Atlas to build a head to their specifications. Alternatively, the company will provide a detailed interface control document to enable customers to develop heads of their own. Engineering challenges Marbach says the hardest part of any AUV development project is to get it ready for series production, to a state in which it can be said to be mature, that it works reliably and that each vehicle off the line will perform to the same consistent standard. “The design has to be bullet-proof, more or less,” he says. As well as meeting all the requirements, the engineering Unmanned Systems Technology | August/September 2017 In the SwapHead concept, the SeaCat has a standard interface for mechanical, electrical and data connections The hardest part of any AUV development is to get it ready for series production, to a state where it works reliably. The design has to be bullet-proof