The result of the inference of the GMF as seen on the northern POS. Panel a: averaged LOS component of the test magnetic field, shown in Fig. 2a. Panel b: noisy integrated data that were used along with the sparse and local data shown in Fig. 2b in order to define the LOS-informed posterior distribution. The noise covariance was set to 0.5 μG², and the density of integrated measurements was 0.1 deg⁻². Panel c: averaged LOS component of the mean 3D configuration of the approximating posterior distribution for the data of Figs. 2b and 6b.