http://orcid.org/0000-0003-4140-9374
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Abstract
Even though the entire Baltic Sea is included in previous geoid modelling projects such as the NKG2015 and EGG07, the accuracy of contemporary geoid models over marine areas remains unknown, presumably being offshore around 15–20 cm. An important part of the international cooperation project FAMOS (Finalising Surveys for the Baltic Motorways of the Sea) efforts is conducting new marine gravity observations for improving gravimetric quasigeoid modelling. New data is essential to the project as the existing gravimetric data over some regions of the Baltic Sea may be inaccurate and insufficiently scarce for the purpose of 5 cm accuracy geoid modelling. Therefore, it is important to evaluate geoid modelling outcome by independent data, for instance by shipborne GNSS measurements. Accordingly, this study presents results of the ship-borne marine gravity and GNSS campaign held on board the Estonian Maritime Administration survey vessel “Jakob Prei” in West-Estonian archipelago in June/July 2016. Emphasis of the study is on principles of using the GNSS profiles for validation of existing geoid models, post-processing of GNSS raw data and low-pass filtering of the GNSS results. Improvements in geoid modelling using new gravimetric data are also discussed. For example, accuracy of geoid models including the new marine gravity data increased 11 mm as assessed from GNSS profiles. It is concluded that the marine GNSS profiles have a potential in providing complementary constraints in problematic geoid modelling areas.
Additional information
Notes on contributors
Sander Varbla
Sander VARBLA, master’s student, Tallinn University of Technology, Department of Civil Engineering and Architecture, Road Engineering and Geodesy Research Group.
Artu Ellmann
Artu ELLMANN received his MSc degree in geodesy from the Moscow State University of Geodesy and Cartography (formerly MIIGAiK) in 1993 and a PhD degree from the Royal Institute of Technology (KTH) in Stockholm in 2004. He is currently Professor in Geodesy at the Department of Civil Engineering and Architecture, School of Engineering at the TTÜ. National correspondent to the International Association of Geodesy (IAG) since 2006. His research interests include physical geodesy (gravity field and geoid modelling in particular) and remote sensing applications for engineering surveying.
Silja Märdla
Silja MÄRDLA received her MSc degree in geodesy from TTÜ, currently she is a PhD candidate and research scientist at Tallinn University of Technology focusing on gravity field and geoid modelling studies. She has also studied construction geodesy and terrestrial laser scanning related problems.
Anti Gruno
Anti GRUNO, received his MSc degree in geodesy from TTÜ, currently working Estonian Land Board Photogrammetry Department. Main task is Airborne Lidar scanning data processing.
