Vegard Ophaug

Vegard Ophaug

Professor

  • Department of Geomatics

I am a geodesist with research interests in gravity field modeling, geoid computation, satellite and terrestrial gravimetry, and satellite altimetry, with applications to sea-level science, ocean dynamics, geodynamics, glaciology, and climatology.

This short video nicely sums up what my research is about. See also this interview with Kristian Breili for more on how we measure terrestrial gravity (in Norwegian).

During my PhD studies, I was mainly involved in the GOCODYN project (2014-2018), which investigated how recent developments within geodesy can improve our understanding of sea level, ocean dynamics, and gravity field in the Norwegian coastal zone. It encompassed various topics such as optimal combination of recent satellite and regional gravity data, dedicated coastal altimetry products, modern geoid computation techniques, and the observation and modeling of temporal gravity variations due to postglacial rebound.

Currently, I am working with Christian Gerlach and Kristian Breili (and other external partners) on investigating different approaches to error propagation in geoid computation, as well as the combination of sea-level observations from various sensors, such as sea-level recorders, new-generation altimetry satellites, and unmanned surface vehicles (USVs). We supervise the SEGREF project (2021-) of PhD candidate Matea Tomić, investigating geoid computation, error budgeting and combination strategies for different types of geodetic and oceanographic observations (including new-generation SAR altimetry) for determining a transformation between chart datum and NN2000.

Since 2004, the Department of Geomatics has an FG5-type absolute gravimeter at its disposal, which has been used in various observation campaigns over the years, with main applications to postglacial rebound and glaciology studies. Recent research activities within terrestrial gravimetry included supervision of the HYDROGRAV (2019-2023) project of PhD candidate Brian Bramanto, which concerned hydrological contributions to terrestrial gravity measurements.

  • Publications

    List of publications from my research. (Cristin)

    • Tomic, M., Breili, K., Gerlach, C., Ophaug, V. (2024): Validation of retracked Sentinel-3 altimetry observations along the Norwegian coast. Adv. Space Res., doi:10.1016/j.asr.2024.01.055
    • Bramanto, B., Breili, K., Gerlach, C., Gumilar, I., Ophaug, V., Wahyudi, E. J. (2023): Geodetic/gravimetric evidence for mass loss in the subsidence area of Bandung, Indonesia. J. Geodyn. 157, doi:10.1016/j.jog.2023.101987
    • Ophaug, V., Gerlach, C. (2020): Error propagation in regional geoid computation using spherical splines, least-squares collocation and Stokes's formula. J. Geod. 94, doi:10.1007/s00190-020-01443-y.
    • Ophaug, V., Breili, K., Andersen, O. B. (2019): A coastal mean sea surface with associated errors in Norway based on new-generation altimetry. Adv. Space Res., doi:10.1016/j.asr.2019.08.010.
    • Idzanovic, M., Ophaug, V., Andersen, O. B. (2017): The coastal mean dynamic topography in Norway observed by CryoSat-2 and GOCE. Geophys. Res. Lett. 44, doi:10.1002/2017GL073777.
    • Ophaug, V., Gerlach, C. (2017): On the equivalence of spherical splines with least-squares collocation and Stokes's formula for regional geoid computation. J. Geod. 91, 1367-1382, doi:10.1007/s00190-017-1030-1.
    • Ophaug, V., Breili, K., Gerlach, C., Gjevestad, J. G. O., Lysaker, D. I., Omang, O. C. D., Pettersen, B. R. (2016): Absolute gravity observations in Norway (1993-2014) for glacial isostatic adjustment studies: The influence of gravitational loading effects on secular gravity trends. J. Geodyn. 102, 83-94, doi:10.1016/j.jog.2016.09.001.
    • Ophaug, V., Breili, K., and Gerlach, C. (2015): A comparative assessment of coastal mean dynamic topography in Norway by geodetic and ocean approaches. J. Geophys. Res. Oceans 120, 7807-7826, doi:10.1002/2015JC011145.
  • Teaching

    Currently, I am course responsible for and teaching contributor to

    Geomatics undergraduate:

    • GMLM102 (5 credits) - Geodetic surveying basics (Grunnleggende landmåling)
    • GMGD200 (10 credits) - Geodesy (Geodesi)
    • GMGD230 (5 credits) - Marine geodesy (Marin geodesi)

    Geomatics graduate:

    • GMGD310 (10 credits): Physical geodesy (Fysisk geodesi)

    In addition comes supervision of PhD and master students.