“…Since the late 1970s, coarse resolution (25 -50km) soil moisture products derived from past and present microwave radiometers (Advanced Microwave Scanning Radiometer (AMSR-E) (Njoku et al, 2003) and WindSat (Li et al, 2010)) and scatterometers (European Remote Sensing satellites (ERS) scatterometer (SCAT) (Wagner a (Bartalis et al, 2007;Naeimi et al, 2009)) have been available on an operational basis. Data from the European Space Agency (ESA) Soil Moisture and Ocean Salinity (SMOS) (Kerr et al, 2012;Mecklenburg et al, 2012) and the National Aeronautics and Space Administration (NASA) Soil Moisture Active Passive (SMAP) (Entekhabi et al, 2010) dedicated soil moisture missions are strengthening this record of observations and further facilitating the study of long term soil moisture behaviour (please see Petropoulos et al (2015) and Zeng et al (2015) for further details of available satellite derived soil moisture products). With the availability of these products, it is necessary to validate them using independently derived soil moisture observations obtained through in-situ monitoring, models, or with different satellite sensors (van Doninck et al, 2012;Ochsner et al, 2013;Al-Yaari et al, 2014).…”