The survey vessels (VS) CAPELLA and KOMET as well as the survey, wreck search and research vessels (VWFS) ATAIR, DENEB and WEGA are used in hydrographic surveying and wreck search.
The Geodetic Group is responsible for ensuring hydrographic surveying in the North Sea and Baltic Sea and the digital coverage of coastal topography. It digitally records the topography of the coastal zone and prepares the data for further use. Modern Global Navigation Satellite Systems (GNSS) and terrestrial surveying systems are used for this task. The positioning of the systems is carried out by means of a satellite positioning service (SAPOS).
The processing, visualisation, documentation and archiving are carried out in a Geographical Information System, which is coupled to a geodetic calculation software. Thus it is possible to continuously observe the inventory of objects on the coast and in the harbours and to document structural changes by supplementary measurements.
For the GNSS positioning of the survey units and for tide correction of the measured water depths onboard the ships, the survey systems require correction data in real time.
This method is mainly used with the SAPOS-HEPS service using the generally available mobile network. Since network coverage is not ensured in all survey areas, the BSH operates PDGPS reference stations at selected locations such as lighthouses, which due to their height are expected to have a long range for the transmission of correction data. These are equipped with UHF (decimetric wave) and VHF (ultra-short wave) transmitters. This makes it possible to feed the survey data in real time on board, up to 70 km away from the reference station and with an accuracy of <10 cm. Some of these stations are only used temporarily. In addition to maintenance and ongoing operation, the Geodetic Group is also responsible for installation, calibration and troubleshooting of the systems. It currently operates seven stations in the North Sea area and six stations on the Baltic Sea coast.
Another surveying task at the BSH is the calibration of sensors on the ships of the BSH. All systems on board the survey vessel are calibrated to each other. The resulting offsets are made available to the surveying software in digital form. This is the only way to ensure high-quality and uniform observations of the seabed.
The Geodetic Group is responsible for the surveying part of the training to become a geomatics technician at the BSH. Two instructors are available for these activities in the field and in the office.