More information about geoid models can be found at the pages about the geoid.
SWEN17_RH2000 is a geoid model that has been adjusted to SWEREF 99 and the height system RH 2000. The model includes a correction for the postglacial land uplift and an interpolated, smooth representation of the GNSS/levelling residuals to make the transition from heights above the ellipsoid in SWEREF 99 to heights above sea level in RH 2000.
The standard uncertainty of SWEN17_RH2000 has been estimated to 8‑10 mm everywhere on the Swedish mainland, Öland and Gotland with exception of a few areas where the uncertainty is larger. These areas are in the far north on the border to Norway and in lake Vättern (standard uncertainty approximately 2‑3 cm) and the highest mountains to the north-west, depending on the difficulties to model a gravimetric model in mountainous areas (standard uncertainty about 2‑4 cm). The standard uncertainty at sea is also larger; some 2‑4 cm in coastal waters and probably around 5‑10 cm further out to sea.
The geoid models are represented by geoid heights in a regular grid, from which geoid heights in other points can be calculated by a suitable interpolation method, e.g. bicubic splines. Bilinear interpolation using the four closest node points will result in a slightly larger interpolation error, but still very small compared to the uncertainty of the geoid model. Compared to prior geoid models, the grid resolution is twice as high. The resolution is the same as for the underlying gravimetric geoid model, i.e. 0.01 x 0.02 degrees, in order not to miss high-frequent information in the gravimetric geoid model. However, this results in larger geoid files.
The model can be downloaded in three formats, either as a binary grid or two different ASCII formats. The geoid files, as well as interpolated control points, can be found in the list below. A more detailed description of the model will be given in a so-called Lantmäterirapport.
SWEN17_RH70 is the corresponding model for conversion from SWEREF 99 to the older height system RH 70. This model has been computed from SWEN17_RH2000 by taking care of the difference between the two height systems. The model includes a correction for the postglacial land uplift and an interpolated, smooth representation of the GNSS/levelling residuals.
The standard uncertainty of SWEN17_RH70, close to the benchmarks of the national precise levelling network, is similar to the one of SWEN17_RH2000 on land, under the assumption that RH 70 is considered as realised by the RH 70 heights of stable benchmarks along the precision lines of the second precise levelling and the RHB 70 heights for the benchmarks of the third precise levelling.
Files from Lantmäteriet
Interactive computation of geoid height
Compute geoid height, using the SWEN17 models.