The Envisat ASAR data were in AP mode and VV/VH polarization combinations, and the overpass time was approximately at 11:31 BJT. The quadrates were divided into 4×4 subsites, with each one spanning a 30×30 m2 plot. Those provide reliable ground data for retrieval and validation of soil moisture from active remote sensing approaches.
Observation items included:
(1) soil moisture by POGO soil sensor in No. 1, 2 and 3 quadrates; 25 corner points of each subsite were chosen for the soil temperature, soil volumetric moisture, the loss tangent, soil conductivity, and the real part and the imaginary part of soil complex permittivity;
(2) the soil temperature by the handheld infrared thermometer 3# and 5# from BNU in No. 1 quadrate, 1# and 4# in No. 2 quadrate, and 2# and 6# in No. 3 quadrate; 25 corner points of each subsite were measured twice by two groups, and time, the maximum, the minimum and the mean value, and the land cover types were all recorded.
(3) spectrum of the grassland, the bare land and the stellera by the thermal infrared spectrometer, 102F.
The dataset includes ASAR images, preprocessed data of the thermal infrared spectrometer, 102F, the surface temperature and soil moisture synchronizing with Envisat ASAR.
Data Citation Ma Mingguo, Gao Hongchun, Li Hongxing, Liu Chao, Ran Youhua, Ren Huazhong, Yu Yingjie. WATER: Dataset of ground truth measurements synchronizing with Envisat ASAR in the A'rou foci experimental area on Jul. 14, 2008. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences; Beijing Normal University. 2008. doi:10.3972/water973.0008.db
The dataset is generated from the "Watershed Airborne Telemetry Experimental Research (WATER) “, the user must have a clear statement in the article of the original data source and adopt the reference style providing by the metadata in the References section.