WATER: Dataset of ground truth measurements synchronizing with Envisat ASAR in the Linze grassland foci experimental area on May 24, 2008

The dataset of ground truth measurements synchronizing with Envisat ASAR was obtained in the saline plot B, the alfalfa plot D and the barley plot E of the Linze grassland foci experimental area on May 24, 2008. The data were in AP mode and VV/VH polarization combinations, and the overpass time was approximately at 11:34 BJT. The quadrate was divided into 6×6 subsites, with each one spanning a 120×120 m2 plot. Corner points were chosen. Simultaneous with the satellite overpass, numerous ground data were collected, soil gravimetric moisture, volumetric moisture, and soil bulk density after drying by the cutting ring (100cm^3), the mean soil temperature from 0-5cm by the probe thermometer, and the land surface radiative temperature measured three times by the hand-held infrared thermometer in plot B; soil moisture, soil conductivity, the soil temperature, and the real part of soil complex permittivity by WET, the mean soil temperature from 0-5cm by the probe thermometer, and the land surface radiative temperature measured three times by the hand-held infrared thermometer in plot D; the soil temperature, soil moisture, the loss tangent, soil conductivity, the real part and the imaginary part of soil complex permittivity by the POGO soil sensor, the mean soil temperature from 0-5cm by the probe thermometer, and the land surface radiative temperature measured three times by the hand-held infrared thermometer in plot E. Data were archived in Excel file. Those provide reliable ground data for retrieval and validation of soil moisture and alinity content with active microwave remote sensing approaches. See WATER: Dataset of setting of the sampling plots and stripes in the Linze station foci experimental area for more information.

本数据集收集于2008年5月24日，在林则草场实验区B区盐碱地、D区紫花苜蓿地及E区大麦地，与Envisat ASAR卫星同步测量的真实测量数据。数据采集模式为AP模式，采用VV/VH极化组合，过境时间约为北京时间11:34。该正方形区域被划分为6×6个子区域，每个子区域覆盖120×120平方米。选取了角落点。在卫星过境的同时，收集了大量地面数据，包括土壤重力水含量、体积水含量、经切割环干燥后的土壤容重（100cm³）、0-5cm深度的平均土壤温度（探针温度计）、在B区通过手持式红外温度计测量三次的地表辐射温度；在D区通过WET测量土壤湿度、土壤电导率、土壤温度和土壤复介电率的实部，0-5cm深度的平均土壤温度（探针温度计）以及通过手持式红外温度计测量三次的地表辐射温度；在E区通过POGO土壤传感器测量土壤温度、土壤湿度、损耗角正切、土壤电导率、土壤复介电率的实部和虚部，0-5cm深度的平均土壤温度（探针温度计）以及通过手持式红外温度计测量三次的地表辐射温度。数据以Excel文件形式归档。这些数据为利用主动微波遥感方法检索和验证土壤湿度和盐分含量提供了可靠的地面数据。更多信息请参见WATER：林则站实验区采样点和条纹设置数据集。