Backscattering data obtained from ERS-1 SAR imagery are used to verify the ability to detect field scale spatial and temporal variations of surface soil moisture from spaceborne microwave sensors, and to test sub-field scale detection capability. The investigated area is part of the Sele basin, in southern Italy. For two dates, corresponding to satellite overflights of the area during November, 1993, Time Domain Reflectometry (TDR) measurements were taken over a dense sampling grid in two bare soil fields, in order to acquire ground-truth information for soil moisture in the upper 10 cm soil layer. Statistical analysis shows a good agreement between the two types of data at the field scale; at the sub-field scale, a similarity in the spatial structure ofTDR and radar signal is found through cross-covariance and covariance analysis. In addition, one of the dates gives the possibility of observing the response of the SAR sensor and of the TDR for a field showing quasi-uniform ponding conditions.