Frag Out! Magazine
Issue link: https://fragout.uberflip.com/i/1115818
the largest of the three, features batter- ies, HISAS sidescan sonar antennas and light diodes for the camera. The aft section includes system control elements, an HD camera, another auxiliary propeller, and a drive shaft with a power screw. The successive development versions of Hugins for military applications are used by naval forces of Norway (one vehicle), Italy (one vehicle), Finland (three vehicles), Po- land (currently one vehicle), and of a few other countries. The "civil" versions are used by several dozen companies operating in the mining and offshore industry. According to manufacturer's declarations, the vehicle in the version used on "Kormo- ran" offers an endurance of "over 30 hours" at an optimal speed. The exact parameters depend on the type of the task carried out and on the hydrological features of the ba- sin the vehicle is used in. The most important system carried by the vehicle is the HISAS 1032 sidescan synthetic aperture sonar. It's the prima- ry sensor of the vehicle, able to get very high-resolution images of the seabed. The sonar has been developed by Kongsberg with mine countermeasure tasks in mind in particular, and with a special consideration of the feature of mine detection in adverse conditions, typical of the Norwegian rocky sea bottom. The applied technology of synthetic aper- ture makes the sonar able to detect very small objects found on the seabed (like mines or improvised explosive devices). Thanks to the application of SAS technol- ogy, the system makes it possible to get sonar images of the maximum resolution of 2x2 cm, with the value being independent of the distance between the processor and the object searched for. This means that a single Hugin is theoretically able to scan about 2.4 km2 of seabed in one hour of its operation. Apart from acting as a synthetic aperture sonar and providing hi-res images, HISAS offers a few additional features. The first of them is the ability to create "multi-as- pect"/3D images of the detected objects, which increases the likelihood of identify- ing any potential dangers. Another feature is the so-called "shadow enhanced SAS", which is an ability to analyze the shadow cast by a mine or another object on the seabed. It is employed at the stage of "pro- cessing" of the data provided by the sonar. It is a very effective but time-consuming (i.e. requiring a lot of computing power) method, able to enhance the standard im- age analysis. The features of the HISAS sonar are supplemented and supported by other sensors found in the vehicle. The first is the multi-beam EM 2040 echosounder, able to form a "sonar mosaic" – a 3D image of the scanned object. In order to enable autonomous visual identification of the de- tected object, the vehicle comes also with a camera offering monochromatic hi-res NAVY