Fig. 1From: A regional geomagnetic field model over Southern Africa derived with harmonic splines from Swarm satellite and ground-based data recorded between 2014 and 2019Map showing the area of interest with four INTERMAGNET observatories in the southern African region (HER, HBK, TSU and KMH), represented by black triangles, and geomagnetic repeat stations that are represented by black dots and empty circles. The empty circles represent repeat stations with some outlier values; see text for detailsBack to article page