The dataset of ground-based RPG-8CH-DP microwave radiometer and ground truth observations for soil freeze/thaw cycle was obtained in the A'rou foci experimental area from Mar. 10 to 11, 2008. The radiometer was set 4.5m height above a smooth land, which was covered with snow less than 10cm deep. The field of view was roughly determined and not as ideal. Frozen soil was observed clockwise 240° and snow clockwise 270° with the truck head as the 0 degree azimuth; the elevation angle was set at -40° for the former, and from -20° to -70° for the latter. Observation items included surface soil moisture (microwave drying to get the gravimetric moisture), the soil temperature by the thermal resistor and vegetation. The shallow layer of the site was covered with withered grass with exuberant roots underground due to rich organic. The soil temperature changes were reflected by the thermal resistor and recorded by the DataTaker. The brightness temperature was archived as .BRT and .txt files (the ASCII format). Data in two formats were the same. Each row in .txt format was listed by year, month, date, hour, minute, second, 6.925GHz (h), 6.925GHz (v), 10.65GHz (h), 10.65GHz (v) , 18.7GHz (h), 18.7GHz (v), 36.5GHz (h), 36.5GHz (v), the elevation angle, and the azimuth angle. Values for 6.925GHz and 10.65GHz were zero due to disfunction.

The dataset of snow spectral reflectance observations was obtained in the Binggou watershed foci experimental area from Dec. 5 to Dec. 15, 2007 during the pre-observation period. The aims of the measurements were to verify feasibility of the predetermined observation schemes and to collect data for retrieval from remote sensing approaches. All data were acquired by ASD spectrometer from Xinjiang Meteorological Administration. Observation items included: (1) Random observations on snow spectrum in the chosen snowpack at the Binggou cold region hydrometeorological station on Dec. 5, 6 and 7, 2007 (2) Snow spectrum observations in BG-A simultaneous with MODIS and Terra MISR on Dec. 10, 2007 (3) The pure and the mixed snow pixel spectrum in BG-A on Dec. 15, 2007 (4) Multi-angle snow spectrum in the chosen snowpack in BG-A on Dec. 15, 2007 Seven subfolders including raw data and pre-processed data are named after the acquisition time, Dec. 5, 2007, Dec. 6, 2007, Dec. 7, 2007, Dec. 10, 2007, Dec. 13, 2007, Dec. 15, 2007 and Dec. 15, 2007, respectively.

The dataset of continuous LST (Land Surface Temperature) observation was obtained by the automatic thermometer in the Linze grassland foci experimental area. Six devices numbered from #1 to #6 were used. Observations were carried out in the reed plot A, the saline plots B and C, the alfalfa plot D, the barley plot E and the temporary farmland on Jun. 10 and 11, 2008 and in plots A, B and E on Jul. 11, 2008. Observation time and the land surface radiative temperature were archived in Word, txt and Excel format. See WATER: Dataset of setting of the sampling plots and stripes in the foci experimental of Linze station area for more information.

The dataset of ground-based microwave scatterometer (C-5 and LS-C-5; S-3; LS-S-3) and ground truth observations was obtained in the Linze grassland foci experimental area. Besides, TDR-200 was also used. Observation items included: (1) soil moisture of the grassland on Jul. 9, 2008. HH, HV, VV and VH polarization combinations were applied. (2) soil moisture of the maize field on Jul. 10, 2008. VV, HH, VH and HV polarization combinations were applied. (3) humidity of the grassland at around 11:30am on Jul. 11, 2008. VH, HH, VV and HV polarization combinations were applied.

The dataset of GPS radiosonde observations was obtained at an interval of 2 seconds in the cold region hydrology experimental area in March, 2008 and the arid region hydrology experimental area from May to July, 2008. The items were the air temperature, relative humidity, air pressure, the dew temperature, the water vapor mixing ratio, latitudinal and longitudinal wind speeds, the wind speed and direction. Simultaneous with the satellite/airplane overpass, GPS radiosonde observations were carried out: Binggou watershed on Mar. 14, A'rou on Mar. 15, Binggou watershed on Mar. 15, Biandukou on Mar. 17, Binggou watershed on Mar. 22, Binggou watershed on Mar. 29, and A'rou on Apr. 1 for the upper stream experiments; Linze grassland station on May 30, Yingke oasis on Jun.1, Huazhaizi desert station on Jun. 4, Linze grassland station on Jun. 5, Linze grassland station on Jun. 6, Huazhaizi desert station on Jun. 16, Yingke oasis on Jun. 29, Binggou watershed on Jul. 5, Yingke oasis on Jul. 7, Linze grassland station on Jul. 11, and Yingke oasis at 0, 4:10, 8:09, and 12:09 on Jul. 14 for middle stream experiments.

The dataset of ground truth measurement synchronizing with the airborne microwave radiometers (L&K bands) mission was obtained in the Biandukou foci experimental area on May 25, 2008. Observation items included: (1) the soil temperature in L1, L2, L3, L4, L5, L6 and L7; (2) roughness measured by the roughness grid board and collected by the digital camera. Files with "result" field were processed data, in which the first row was RMS height (cm; one value), the second row was distance (cm), and the third row was correlation function (cm; changed into correlation length when it is 1/e). (3) GPR and TDR data. Five files were included, roughness photos and preprocessed data, the soil temperature, coordinates of quadrates and sampling lines, GPR and microwave radiometer data. All were archived as Excel and .txt files. Those provide reliable ground data for development and validation of soil moisture and freeze/thaw algorithms from active remote sensing approaches.

The dataset of ground truth measurement synchronizing with Envisat ASAR was obtained in No. 2 and 3 quadrates of the A'rou foci experimental area on Mar. 14, 2008. The Envisat ASAR data were in AP mode and VV/VH polarization combinations, and the overpass time was approximately at 23:21 BJT. The quadrates were divided into 4×4 subsites, with each one spanning a 30×30 m2 plot. Only the corner points of each subsite were chosen for observations. Those provide reliable ground data for retrieval and verification of soil moisture from active remote sensing approaches. In No. 2 quadrate, simultaneous with the satellite overpass, numerous ground data were collected, the soil temperature, soil volumetric moisture, the loss tangent, soil conductivity, and 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, the surface radiative temperature measured three times by the hand-held infrared thermometer, soil gravimetric moisture, volumetric moisture, and soil bulk density after drying by the cutting ring (100cm^3). In No. 3 quadrate, simultaneous with the satellite overpass, numerous ground data were collected, the soil temperature, soil volumetric moisture, the loss tangent, soil conductivity, and the real part and the imaginary part of soil complex permittivity by the POGO soil sensor, soil volumetric moisture by ML2X, the mean soil temperature from 0-5cm by the probe thermometer, the surface radiative temperature measured three times by the hand-held infrared thermometer, soil gravimetric moisture, volumetric moisture, and soil bulk density after drying by the cutting ring (100cm^3). Surface roughness was detailed in the "WATER: Surface roughness dataset in the A'rou foci experimental area".

The dataset of runoff measuring weir observations at the hydrological section was obtained in the Pailugou watershed foci experiment area during two full years from Oct. 2006 to Oct. 2008. The ice flow measurement and the container aet were used manually. The measurement was carried out every five days from Oct. 2006 to Apr. 2007, three times a day from May to Sep. 2007, every five days from Oct. 2007 to Apr. 2008, once a day from May to Sep. 2008, and every five days during Oct. 2008. Data were archived in Excel format.

The dataset of ground truth measurement synchronizing with EO-1 Hyperion was obtained in the Yingke oasis and Huazhaizi desert steppe foci experimental areas on May 25, 2008. Observation items included: (1) Atmospheric parameters on the ICBC resort office roof by CE318 (produced by CIMEL in France). The total optical depth, aerosol optical depth, Rayleigh scattering coefficient, column water vapor in 936 nm, particle size spectrum and phase function were then retrieved from these observations. The optical depth in 1020nm, 936nm, 870nm, 670nm and 440nm were all acquired by CE318. Those data include the raw data in k7 format and can be opened by ASTPWin. ReadMe.txt is attached for detail. Processed data (after retrieval of the raw data) in Excel format are on optical depth, rayleigh scattering, aerosol optical depth, the horizontal visibility, the near surface air temperature, the solar azimuth, zenith, solar distance correlation factors, and air column mass number. (2) Ground object reflectance spectra f new-born rape and the bare land in Biandukou foci experimental area by ASD FieldSpec (350~2500 nm) from BNU. Raw data were binary files direct from ASD (by ViewSpecPro), and pre-processed data on reflectance were in Excel format. (3) Soil moisture (0-40cm) by the cutting ring and the soil temperature (0-40cm) by the thermocouple in Huazhaizi desert No. 1 plot and the windbreak forest; and soil moisture and the soil temperature (0-100cm) in Yingke oasis maize field. Data were archived in Excel format. (4) LAI. The maximum leaf length and width of each alfalfa and barley were measured. Data were archived in Excel format. (5) Coverage of maize and wheat in Yingke oasis maize field, of vegetation (Reaumuria soongorica) in Huazhaizi desert No. 1 and 2 plots by the self-made coverage instrument and the camera (2.5m-3.5m above the ground). Based on the length of the measuring tape and the bamboo pole, the size of the photo can be decided GPS date were also collected and the technology LAB was applied to retrieve the coverage of the green vegetation. Besides, such related information as surroundings environment was also recorded. Data included the primarily measured image and final fraction of vegetation coverage.

The dataset of ground truth measurements synchronizing with Envisat ASAR and ALOS PALSAR was obtained in the Linze station 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. Observation items included: (1) soil moisture (0-5cm) measured once by cutting ring method at corner points of the 40 subplots of the west-east desert transit zone strip, one time by cutting ring method in nine subplots of the north-south desert transit zone, strip and once by the cutting ring and three times by ML2X Soil Moisture Tachometer in the center points of nine subplots of Wulidun farmland quadrates . The preprocessed soil volumetric moisture data were archived as Excel files. (2) surface radiative temperature by measured two handheld infrared thermometer (5# and 6# from Cold and Arid Regions Environmental and Engineering Research Institute which were both calibrated) in 40 subplots of the west-east desert transit zone strip (repeated 14-30 times each), and nine subplots of the north-south desert transit zone strip (repeated 12-30 times). There are 34 sample points in total and each was repeated three times synchronizing with the airplane. Photos were taken. Data were archived as Excel files. (3) LAI, the plant height and the spacing measured by the ruler and the set square in Wulidun farmland quadrates and Linze station quadrates. Part of the samples were also measured by LI-3100. Data were archived as Excel files. See the metadata record “WATER: Dataset of setting of the sampling plots and stripes in the Linze station foci experimental area” for more information of the quadrate locations.

The dataset of groundwater level was obtained by the automatic water gauges at an interval of 1 hour from Dec. 25 2007 to Jul. 6, 2009. In order to monitor changes in the groundwater level and in the groundwater temperature in the cold region hydrology experiment area, six sets of instruments (the HOBO pressure type mario/thermograph: U20-001-01; U20-001-01-TI) were scattered by Cold and Arid Regions Environmental and Engineering Research Institute, CAS in the Yingke oasis, Xinmiao village in Daman township, Daman Water Management office, Wangqizha village in Xiaoman township, Yanhe village in Mingyong county, Xiaowan village in Wujiang township and Liuquan village in Xindun township respectively. The items were mainly the groundwater pressure and the groundwater temperature . Based on the air pressure obtained in the Yingke oasis station, the groundwater pressure by HOBO could be changed into the grounwater depth, and the groundwater level could be developed by differential GPS.

The dataset of ground truth measurements synchronizing with ASTER was obtained in the Yingke oasis and Huazhaizi desert steppe foci experimental areas on May 28, 2008. Observation items included: (1) Atmospheric parameters in Huazhaizi desert No. 2 plot by CE318 (produced by CIMEL in France). The total optical depth, aerosol optical depth, Rayleigh scattering coefficient, column water vapor in 936 nm, particle size spectrum and phase function were then retrieved from these observations. The optical depth in 1020nm, 936nm, 870nm, 670nm and 440nm were all acquired by CE318. Those data include the raw data in .k7 format and can be opened by ASTPWin. ReadMe.txt is attached for detail. Processed data (after retrieval of the raw data) in Excel format are on optical depth, rayleigh scattering, aerosol optical depth, the horizontal visibility, the near surface air temperature, the solar azimuth, zenith, solar distance correlation factors, and air column mass number. (2) Photosynthesis by LI-6400. Raw data were archived in the user-defined format (by notepat.exe) and processed data were in Excel format. (3) Reflectance spectra in Yingke oasis maize field by ASD FieldSpec (350-2500nm, the vertical canopy observation and the transect observation) from Institute of Remote Sensing Applications (CAS), and in Huazhaizi desert No. 2 plot by ASD FieldSpec (350-1603nm, the vertical observation and the transect observation for reaumuria soongorica and the bare land) from Beijing Academy of Agriculture and Forestry Sciences. The grey board and the black and white cloth were also used for calibration spectrum. Raw data were binary files direct from ASD (by ViewSpecPro), and pre-processed data on reflectance were in Excel format. (4) Coverage fraction of maize and wheat by the self-made instrument and the camera (2.5m-3.5m above the ground) in Yingke oasis maize field. Based on the length of the measuring tape and the bamboo pole, the size of the photo can be decided. GPS date were also collected and the technology LAB was applied to retrieve the coverage of the green vegetation. Besides, such related information as the surrounding environment was also recorded. Data included the primarily measured image and final fraction of vegetation coverage. (5) the radiative temperature of maize, wheat and the bare land in Yingke oasis maize field by ThermaCAM SC2000 using ThermaCAM SC2000 (1.2m above the ground, FOV = 24°×18°),. The data included raw data (read by ThermaCAM Researcher 2001), recorded data and the blackbody calibrated data (archived in Excel format). (6) the radiative temperature by the automatic thermometer (FOV: 10°; emissivity: 0.95), 3 for maize canopy, the bare land and wheat canopy in Yingke oasis maize field, one for maize canopy in Huazhaizi desert maize field, and 2 for vegetation and the desert bare land in Huazhaizi desert No. 2 plot,at nadir at a time interval of one second. Raw data, blackbody calibrated data and processed data were all archived in Excel format. (7) Maize albedo by the shortwave radiometer in Yingke oasis maize field. R =10H (R for FOV radius; H for the probe height). Data were archived in Excel format. (8) LAI in Yingke oasis maize field. The maximum leaf length and width of each maize and wheat were measured. Data were archived in Excel format. (9) FPAR (Fraction of Photosynthetically Active Radiation) of maize and wheat by SUNSACN and the digital camera in Yingke oasis maize field. FPAR= (canopyPAR－surface transmissionPAR－canopy reflection PAR+surface reflectionPAR) /canopy PAR; APAR=FPAR* canopy PAR. Data were archived in the table format of Word. (10) The radiative temperature in Yingke oasis maize field (the transect observation), Yingke oasis wheat field (the transect observation), Huazhaizi desert maize field (the transect observation) and Huazhaizi desert No. 2 plot (the diagonal observation) by the handheld infrared thermometer (BNU and Institute of Remote Sensing Applications). Raw data (in Word format), blackbody calibrated data and processed data (in Excel format) were all archived.