 The soil moisture and ocean salinity, SMOS, mission is designed to measure surface soil moisture data of global coverage every three days. To validate the accuracy of the data, a soil moisture and soil temperature sensor network was established in the Skjern River catchment, Denmark. The network consists of three clusters arranged along the precipitation gradient, each containing six sensors. The sensors measure soil moisture and temperature at depths of 0 to 5 centimeters and 5 to 10 centimeters. The network is designed to provide accurate data for comparison with the SMOS satellite data. The data collected by the network shows that the soil moisture and temperature measurements are consistent with the SMOS data, indicating that the network is suitable for validating the accuracy of the SMOS data. This article was authored by S. Bircher, N. Scoo, K. H. Jensen, and others.