Coordination of Vertical Coordinates in the Baltic Sea
The Baltic Sea region is set to unify its vertical datums for nautical charts by 2025, aiming to enhance safety and consistency in navigation. This coordinated effort, led by the Baltic Sea Hydrographic Commission (BSHC), will see the adoption of the European Vertical Reference System (EVRS) as the harmonized vertical reference system.
The EVRS, based on geopotential height, is aligned with the European Vertical Reference Frame (EVRF). The transition to this common vertical reference system is expected to have an impact of around 15-20 cm on depths in the northern parts of the Baltic Sea.
The BSHC's Chart Datum Working Group (CDWG) has identified the importance of this harmonization, given the current inconvenience caused by differing national vertical reference systems. These systems, based principally on mean sea level (MSL), have resulted in difficulties for navigators, data transfer between Hydrographic Offices, and other users of depth and water level data.
The CDWG, which includes representatives from all Baltic Sea Hydrographic Offices, national geodetic and oceanographic organizations, and the Baltic Sea Oceanographic Observation System (BOOS), will guide and follow up the implementation process. They have prepared a roadmap time line, with the goal of establishing the new system in use by 2020.
The harmonized vertical reference system will simplify navigation and reduce the risk of errors due to differing vertical datums. It will also enhance wider and easier use of data in accordance with the INSPIRE directive and enable the full utilization of future enhanced navigation systems based on IHO S-100 standards.
In addition to the transition to the EVRS, the CDWG will also study other water level related issues. These include developing a common geoid model for the Baltic Sea and fostering studies related to dynamic topography of sea surface in the Baltic Sea. The CDWG will also prepare questionnaires to study and clarify relevant issues.
The CDWG, under the leadership of Jyrki Mononen, who has been acting as the chairman since 2013 and holds an MSc in land surveying from the Technical University of Helsinki, will hold annual meetings for decision making, follow up, and to review the current situation concerning harmonization of vertical references.
The CDWG will also study the dynamic topography of the sea surface and how to predict water level changes to meet future needs for more efficient and safer shipping. This initiative was established by the BSHC in 2005, with the aim of studying and fostering the harmonization of vertical reference systems.
The BSHC, through the CDWG, is committed to ensuring that depths on sea and heights on land will be referenced to the same vertical reference system by 2025, improving safety and consistency in navigation across the Baltic Sea.
- The transition to the European Vertical Reference System (EVRS) by 2025, led by the Baltic Sea Hydrographic Commission (BSHC), will not only simplify navigation but also enhance the utilization of future enhanced navigation systems based on IHO S-100 standards, due to the elimination of errors caused by differing vertical datums.
- Beyond the transition to the EVRS, the Chart Datum Working Group (CDWG) will focus on other water level-related issues, such as developing a common geoid model for the Baltic Sea, fostering studies related to dynamic topography of sea surface, and preparing questionnaires to study and clarify relevant issues.
- As climate change continues to impact the environment and the Baltic Sea in particular, the CDWG, under the leadership of Jyrki Mononen, will study the dynamic topography of the sea surface and how to predict water level changes to meet future needs for more efficient and safer shipping, with the long-term goal of improving safety and consistency in navigation across the Baltic Sea.
