Optical viewing systems have a large potential to improve safety for people working at sea. The TRAGVIS project is dedicated to developing a portable active viewing system for maritime search and rescue services.
Accidents can take place at sea at any time. The resulting rescue operations may last several hours, or sometimes even several days. Human eyesight and passive instruments are insufficient for carrying out effective rescue operations at night. Even during daylight hours, visibility conditions are often restricted – for instance due to heavy rain or thick banks of fog – active sensor systems, equipped with their own light source, offer considerable potential in such conditions: range-gating systems (RGS) consist of camera systems that work with active, pulsed (laser) illumination. In this case, the pulses of the light source are synchronised with the camera’s shutter. As a result, the atmospheric backscattered signal – for example caused by the fine particles or water droplets in fog – is largely suppressed. In addition, different depth levels can also be resolved in the image.
Available range-gating systems are often too large and heavy to use on the vessels operated by the German Maritime Search and Rescue Service (Deutsche Gesellschaft zur Rettung Schiffbrüchiger; DGzRS). For this purpose, its design must be as lightweight and compact as possible. The TRAGVIS project has therefore set itself the target of developing a cost-effective, compact and hand-held range-gating sensor – aimed at the needs of its end users – built for use in search and rescue operations at sea.
The research project is being implemented in several stages. In a preliminary study, existing detection and active illumination technologies are identified. In parallel, a needs analysis is being carried out amongst the potential end users. This will be followed by the selection and characterisation of the individual components in order to develop two complete systems. The first system will be installed on the roof of the Institute to study its long-term performance under different visibility conditions. The second device will be tested on board a rescue vessel in cooperation with the German Maritime Search and Rescue Service focusing on finding people and specific objects in the water.
Further key aspects of the TRAGVIS project are the eye safety of the illumination device, development of software and algorithms, and complementary measurements of environmental conditions such as aerosols in order to characterize the sensors. In addition, the benefits for other fields of application and use on other (e.g. airborne) platforms will be assessed.
Weather station / aerosol data
In order to investigate the vision enhancement achieved with Gated-Viewing instruments we measure particle size distributions using a PALAS Fidas 200 S aerosol spectrometer. This data is primarily used to characterize TRAGVIS’ system performance under different environmental conditions. However, it is potentially interesting for different research fields as well (e.g. meteorology, environmental sciences), and we decided to share this data complimentary on demand. In case of interest, please use the contact information below to get in touch with us.
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