Abstract. This case study shows the possibility of using the Advanced MUltiDIrectional Spectralradiometer (AMUDIS) to simultaneously measure the temporal impact of moving clouds on the spectral radiance in different directions and also the first results. For these aims measurements from January 2024 with the AMUDIS in Hannover (Germany 52.39° N and 9.7° E) for cloudless sky and two moving broken clouds situation with different cloud cover are analysed.

From the measuring range of 380–890 nm and the 140 directions, three wavelengths (480 nm, 530 nm, 585 nm) and three directions were selected. These three directions are in the area between north and east and were measured simultaneously.

From these datasets, the temporal variation was calculated for each case with reference to a cloudless moment in the situation (no clouds were observed in the field of view of the input optics). The variations during a broken cloud situation on 18 January were compared with the variations on 10 January under cloudless conditions. It was determined that the spectral radiance was higher by a factor of up to 3 under cloudy conditions. The results show also that the impact of the clouds is dependent on the wavelength, direction and cloud type. The AMUDIS offers another option for validating radiation transfer models, for example.