The dateset of GPR (Ground Penetration Radar) observations was obtained in the A'rou foci experimental area from Mar. 10 to Jun. 19, 2008. Those provide reliable dataset for retrieval of soil moisture and frozen depth from GPR observations. Observation items, sites and time were as follows: (1) GPR in No. 1 quadrate of A'rou on Mar. 10, 2008 (2) GPR+TDR in No. 2 and 3 quadrates of A'rou on Mar. 11, 2008 (3) GPR in No. 1 quadrate of A'rou on Mar. 12, 2008 (4) GPR in No. 2 quadrate of A'rou on Mar. 14, 2008 (5) GPR +TDR in No. 1 quadrate of A'rou on Mar. 15, 2008 (6) GPR +TDR in L6 of A'rou on Mar. 16, 2008 (7) GPR +TDR in L6 of A'rou on Mar. 17, 2008 (8) GPR +TDR in L6 of A'rou on Mar. 18, 2008 (9) GPR +TDR in L6 of A'rou on Mar. 19, 2008 (10) GPR in L6 of A'rou on Mar. 20, 2008 (11) GPR +TDR in No. 3 quadrate of A'rou on Mar. 21, 2008 (12) GPR in No. 1 and 3 quadrates of A'rou on May. 31, 2008 (13) GPR in No. 1 quadrate of A'rou on Jun. 20, 2008
The dataset of ground truth measurements synchronizing with Envisat ASAR was obtained in C1, W2 and B2 of the Biandukou foci experimental area on Mar. 14, 2008, from 23:30 on 14 to 1:00 on 15, to be specific. The ASAR data were in AP mode and VV/VH polarization combinations, and the overpass time was approximately at 23:21 BJT. The wheat stubble land, the deep plowed land and the rape stubble land were chosen for measurements. (1) The surface radiative temperature and the physical temperature were measured by the handheld infrared thermometer. Besides, the land cover type was also recorded. The data can be opened by Microsoft Office. (2) The gravimetric soil moisture (samples from 0-1cm, 1-3cm, 3-5cm, 5-10cm and 10-20cm) was measured by the microwave drying method. (3) The frost depth by the chopstick and the ruler. The soil was considered frozen when it was hard and with ice crystal. The data can be opened by Microsoft Office. Four data files were included, ASAR data, C1, W2 and B2 data.
The dataset of forest canopy gap fraction above the rain gauges observed by the camera (PENTAX K100D, 2400×1600) was obtained at the super site (100m×100m, Qinghai spruce) around the Dayekou Guantan forest station from 9:00-10:40 on Jun. 4, 2008. Observation items included the ground-based LiDAR scanning, the total station measuring, DGPS, tally investigation, LAI, canopy spectrum, camera observations of the canopy, soil evapotranspiration, the soil frozen tube observations, surface roughness, precipitation interception, soil moisture and dry-wet weight of the forest component. A subplot (25m×25m) was chosen for precipitation interception observations with different canopy density, and 32 sets of photos were taken 1m above the ground. Through studying those photos, the number and location of rain gauges could be determined; and then the canopy density could also be further developed.