Primarily we use space geodetic methods such as geodetic very long baseline interferometry (VLBI) and global navigation satellite systems (GNSS), as well as ground based radiometers, and gravimeters. This is augmented by corresponding theoretical work and model calculations.
Measurements of global geodynamical motions
- Land uplift, both vertical and horizontal.
- Absolute sea level rise with a variety of measurements of sea level with respect to the earth’s crust. This is a key parameter for climate models and possible ocean warming.
- Earth deformation effects that are caused by ocean and atmospheric loading of the earth's crust.
- Earth rotation and its variations measured with VLBI.
- Measurements of global crustal motions (plate tectonics) started in 1980. Onsala is one of the radio astronomical observatories that have the longest history in measuring global crustal motions.
- Short-time predictions for weather services, in particular for extreme weather events.
- Long term measurements with GNSS over long time scales, 15 years or more. These have probably a very large potential to monitor climate change and/or validate regonal and global climate models.
- Measurements of molecules in the troposphere and the middle atmosphere with ground based radiometers.
- Measurements of ionospheric variations with GNSS.
Measurements of the gravity field.
- Measurements with a suoperconduction gravimeter to investigate changes in the gravity field due to land uplift.
- Modeling the influence of tides and the atmosphere on gravity measurements.
- Modellling ocean and atmospheric loading effects on gravity measurements.