INTERNATIONAL HYDROGRAPHIC REVIEW 
MAY 2020 
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Likewise, the HRS of the BSCD2000 will be aligned to the respective national HRS on land with 
smooth transitions from country to country. The ellipsoidal height part of the quasigeoid model is 
referenced to the GRS 80 5 ellipsoid (Moritz 1980) of the national realizations of the European 
spatial reference system ETRS89 used for GNSS, whereas the physical height part is again 
consistent with the national levelling heights 6 . 
By that, BSCD2000 is inherently connected with the existing geodetic standards for height deter 
mination (European reference systems ETRS89 and EVRS), making it compatible with the nation 
al geodetic infrastructure, such as GNSS positioning services. In particular, the connection to the 
height systems on land facilitates the planning and construction of offshore projects mainly in the 
energy sector. 
In other words, BSCD2000 shares the “common European zero levels for levelling and 
GNSS”. 
Hence, BSCD2000 for the first time enables seamless cross-border use of real-time GNSS 
positioning in combination with ENC for ship navigation in the Baltic Sea. This also forms the 
foundation of novel techniques that are emerging under the term “Sea Traffic Management”. 
Based on real-time GNSS, high-resolution ENC and unified water level forecasting, the ship can 
continuously monitor its current and projected UKC without echo sounding. One highlight applica 
tion of this “situation-aware navigation” that also has been studied within the EU co-funded 
FAMOS project are ship routes optimized for fuel efficiency, because the fuel consumption of a 
large vessel increases considerably for low UKC due to the hydrodynamic squat effect. 
5 - The geometric shapes of the GRS 80 and the WGS84 ellipsoids are identical at the sub-mm level. 
6 - The Scandinavian countries are particularly affected by postglacial land uplift. BSCD2000 assumes the land uplift 
epoch 2000.0. This means that all relevant coordinates and quantities (ellipsoidal heights, physical heights, quasigeoid 
heights) referto this common epoch, as opposed to the previously inconsistent MSL epochs. Compared to that major 
geophysical effect, the impact of expert-level details - such as treatment of the permanent tide - are within the uncer 
tainty specifications of BSCD2000 and the national EVRS realizations, so that they are not discussed in this paper. For 
such geodetic details, the reader is again referred to the BSCD2000 specification paper (Agren et al. 2019).