The dataset of airborne Polarimetric L-band Multibeam Radiometers (PLMR) was acquired on 5 July, 2012, located in the middle reaches of the Heihe River Basin. The aircraft took off at 10:50 am (UTC+8) from Zhangye airport and landed at 12:20 pm, with the flight time of 1.5 hours. The flight was performed in the altitude of about 2000 m and at the speed of about 220-250 km during the observation, corresponding to an expected ground resolution of about 600 m. The PLMR instrument flown on a small aircraft operates at 1.413 GHz (L-band), with both H- and V-polarizations at incidence angles of ±7.5°, ±21.5° and ±38.5°. PLMR ‘warm’ and ‘cold’ calibrations were performed before and after each flight. The processed PLMR data include 2 DAT files (v-pol and h-pol separately) and 1 KMZ file for each flying day. The DAT file contains all the TB values together with their corresponding beam ID, incidence angle, location, time stamp (in UTC) and other flight attitude information as per headings. The KMZ file shows the gridded 1-km TB values corrected to 38.5 degrees together with flight lines. Cautions should be taken when using these data, as the RFI contaminations are often higher than expected at v-polarization.

The dataset of ground truth measurements synchronizing with the airborne WiDAS mission was obtained in 5 quadrates (30 m×30 m) the Biandukou foci experimental area on May 31, 2008. WiDAS, composed of four CCD cameras, one mid-infrared thermal imager (AGEMA 550), and one infrared thermal imager (S60), can acquire CCD, MIR and TIR band data. The simultaneous ground data were the surface radiative temperature and soil moisture. The quadrates were covered with wheat, rape and bare land. The radiative temperature of 25 corner points (located in No. 2, 3, 4 and 5 quadrates) were acquired. (1) the surface radiative temperature by the handheld infrared thermometer; the quadrate of 30 m×30 m was divided into 21 corner points and each point was measured three times; two for the bare land and one for the vegetation if the two coexist. The data included raw data, recorded data and the blackbody calibrated data. (2) soil moisture (0-5cm) by TDR; 16 center points of the subplot (7.5m×7.5m) were measured three times and the data were archived as Excel files. (3) the time-continuous surface radiative temperature by the fixed automatic thermometer (FOV: 10°; emissivity: 0.95), observing straight downwards at intervals of 1s. Raw data, blackbody calibrated data and processed data were archived as Excel files. Four data files were included, the fixed point temperature in No. 2, 3, 4 and 5 quadrates, the radiative temperature by the handheld infrared thermometer, calibration data and the time-continuous data.

The dataset of diurnal change of FPAR observations was obtained by the quantum meter in the Linze grassland foci experimental area. Incident and reflected radiation of canopy, and land surface in reed, saline grass, alfalfa, cumin and barley were measured and diurnal changes of PAR and Fpar were also acquired. Observations were carried out: In plot E (barley) and cumin field on Jun. 6, 2008; plot D (alfalfa) and plot E on Jun. 11; plot D and E on Jun. 15; plot E on Jun. 16; plot A (reed) on Jun. 20; plot B (saline) on Jun. 22; plot D and E on Jun. 23; plot B (saline) on Jun. 24; plot A and plot E on Jun. 29. 14 Excel files, one Word and one .TXT were archived. See Water: The dataset of setting of the sampling plots and stripes in the Linze grassland foci experimental area for more information.

The dataset of ground truth measurement synchronizing with MODIS was obtained in the Linze grassland foci experimental area on Jun. 11, 2008. Simultaneous east-west ground measurements on the canopy temperature, the half-height temperature and the surface radiative temperature were carried out by the hand-held infrared thermometer at intervals of 125m in 8 quadrates (2km×2km), No.1 quadrate (H01-H08), No.2 quadrate (H09-H16), No.3 quadrate (H17-H24), No.4 quadrate (H25-H32), No.5 quadrate (H33-H40), No.6 quadrat (H41-H48), No.7 quadrate (H49-H56) and No.8 quadrat (H57-H64). Data were archived in Excel file. See WATER: Dataset of setting of the sampling plots and stripes in the foci experimental area of Linze station for more information.

The dataset of land use and land cover investigation was obtained in the arid region hydrology and forest hydrology experiment areas. It included: (1) Land cover investigations in Linze grassland, Yingke oasis, Huazhaizi desert, Dayekou watershed and Zhangye city from May 27 to 31, 2008. GPS data, photos and detailed descriptions were recorded. (2) Land use and land cover investigations in Yingke oasis, Huazhaizi desert and Biandukou foci experimental areas on Jul. 7, 8, 10, 11, 12, 13, 14 and 15, 2008. Data were archived in shapefile, spreadsheet or JPGE formats.

The dataset of ground truth measurement synchronizing with ALOS PALSAR was obtained in the Linze station foci experimental area on Jun. 27, 2008. The data were in FBD mode and HH/HV polarization combinations, and the overpass time was approximately at 23:41 BJT. Soil moisture (0-5cm) was acquired by the cutting ring (50cm^3) meanwhile in the west-east desert strip (the corner point in 40 subplots) and north-south strip (the corner point and the center point in 40 subplots). The quadrate location was listed in coordinates.xls file and 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 sun photometer observations was obtained in the Binggou watershed foci experimental areas (N38°04′1.4″/E100°13′15.6″, 3414.41m) from Mar. 15 to Apr. 2, 2008 (to be specific, the daytime of 15-03-2008, 16-03-2008, 17-03-2008, 18-03-2008, 19-03-2008, 21-03-2008, 22-03-2008, 23-03-2008, 24-03-2008, 25-03-2008, 26-03-2008 and 27-03-2008). Those provide reliable data for retrieval of optical depth, Rayleigh scattering, aerosol optical depth, column water vapor (through data in 936 nm) and with various parameters in 550nm, the horizontal visibility can be further developed by MODTRAN or 6S. The optical depth in 1640nm, 1020nm, 936nm, 870nm, 670nm, 550nm, 440nm, 380nm and 340nm were all acquired. Those data include the raw data in .k7 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. Accuracy of CE318 could be influenced by local air pressure, instrument calibration parameters, and convertion factors. (1) Most air pressure was derived from elevation-related empirical method, which was not reliable. For more accurate result, simultaneous data from the weather station are needed. (2) Errors in instrument calibration parameters need correcting. Thus field calibration based on Langly or interior instrument calibration in the standard light is required. (3) Convertion factors for retrieval of aerosol optical depth and the water vapor of the water vapor channel were also from the empirical method, and need further validation. Raw data were archived in .k7 format and can be opened by ASTPWin. ReadMe.txt is attached for detail. Preprocessed 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. Langley was used for the instrument calibration. Two subfolders including raw data and processed data (Geometric Positions and the Total Optical Depth of Each Channel and Rayleigh Scattering and Aerosol Optical Depth of Each Channel), and three data files (Directions on Data Observations, Raw Data and Proprocessed Data) were archived.

The dataset of the discrimination of C3/C4 species was obtained by the handheld GPS and the digital camera in the Linze station foci experimental area on Jul. 10, 2008. Data fields included Gps, Longitude, Latitude, Photo_num and Describe (descriptions on C3/C4 vegetation and photos).

The dataset focuses on the distribution of sampling plots and stripes in the Yingke oasis and Huazhaizi desert steppe foci experimental areas. (1) YKLZYMD-the maize field plot (180m×180m) at Yingke Weather Station It matches No. 10 flight route. Five subplots were selected, including three maize subplots and 2 wheat subplots. The maize subplots, labeled as YKLZYMD01, YKLZYMD02 and YKLZYMD03, were planted in different directions with a ridge sturctrue, which was composed of single row of maizes and bare soils. The distance of adjacent maize rows, as well as the width of bare soil was 0.5m . YKLZYMD05 (2.46m×1m, along the ridge) was located in the northwest of the plot and interplanted with wheat and soy bean. YKLZYMDD06 was exclusively wheat, and 10 rows (1.5m) vertical to the ridge and 1m along the ridge were measured. This is a key experimental area for canopy spectrum, component reflectance spectra, BRDF, albedo, the photosynthetic rate, FPAR, structural parameters, vegetation coverage, the radiative temperature, surface emissivity, atmospheric parameters and soil moisture. (2) YKXMD-Yingke wheat plot (180m×170m) It matches No. 11 flight route. Wheat and maize were interplanted. Three subplots with the same size (3.4m * 3.4m) were selected for the measurement of vegetaion structural parameters, BRDF, the radiative temperature, vegetation coverage and soil moisture. (3) HZZHMZYMD-Huazhaizi maize plot (240m×240m) It is located between No. 9 and No. 10 flight routes. The maize seed dominates, and wheat, alfalfa and tomatoes were planted. 4 maize subplots and one wheat subplot were chosen to collect the canopy temperature, spectrum, structural parameters and vegetation coverage. (4) HZZHMYD1-Huazhaizi desert No. 1 plot (240m×240m) It is located within No. 4 flight route. 3 subplots (30m×30m) were chosen for reflectance spectra, BRDF, vegetation coverage, emissivity, the radiative temperature, soil moisture, atmospheric parameters by sunphotometer CE318 and surface roughness. In cooperation with experiments in Huazhaizi desert plots and Yingke weather station, simultaneous airborne multiangular thermal infrared camera&CCD-ground observations, simultaneous airborne hyperspectral imager (OMIS)-ground observations, simultaneous OMIS/TM/ASTER/Hyperion/CHRIS/ASAR-ground observations were all accomplished. (5) HZZHMYD2-Huazhaizi desert No. 2 plot It matches No. 5 flight route. Three subplots (10m×10m) for coverage and the radiative temperature and one (30m×30m) for simultaneous temperature and spectrum were chosen. (6) HZZHMYD3-Huazhaizi desert No. 3 plot (30m×30m) It is an intensive plot without simultaneous airporne or spaceborne measurement. (7) DJCYMYD-the maize field at the resort It is an intensive plot (30m×30m) with the maize seeds, mainly for the measurement of radiative temperature and soil moisture. (8) DJCDMD-the barley field at the resort It is mainly for radiative temperature data. (9) DJCDBC-the calibration field at the resort It is located at the ICBC resort. The reflectance spectra of the basketball court, the pool and the vegetation were collected used for radiative calibration of CCD camera in visible and near infrared spectra range. The dataset also includes geographic infomation of each sample point.

The dataset of intensive runoff observations was obtained by the cup type current meter (made in Chongqing Hydrological Instrument Factory) in the Binggou watershed foci experimental area from Jan. 17, 2008 to Dec. 31, 2009. Data directions included: (1) the regular observation before Mar. 14, 2008, once per day; the intensive observation from Mar. 15, 2008 to Apr. 1, 2008, 7-8 times per day and even hourly for some intensive observations (2) three times (9, 14 and 19 BJT) per day from May 3, 2008 to Sep. 17, 2008; from Sep. 17, 2008 on, two times (9 and 18 BJT) per day; the water runoff by evenly spaced method, 20cm, 40cm and 80cm based on different situations The data were named after WATER_Runoff_BG_yyyymmdd-yyyymmdd.csv (WATER_Runoff_BG for Ginggou, yyyymmdd-yyyymmdd for the observation time). The missing data were marked "None".

This dataset includes the retrieved soil moisture products from the airborne PLMR microwave radiometer on 30 June, 7 July, 10 July, 26 July and 2 August, 2012 (UTC+8), in the HiWATER artificial oasis eco-hydrology experimental area of Heihe river basin. The soil moisture (SM), vegetation water content (VWC) and surface roughness (Hr) are simultaneously retrieved based on six brightness temperatures at three incidence angles (7°, 21.5°, 38.5°) and with dual polarization (H and V), by using the Levenberg-Marquardt optimization algorithm. The spatial resolution of the soil moisture products is 700 m, which represent the ~5 cm surface soil moisture according to the L-band observation wavelength. This dataset is in the format of asc, and with UTM projection (47°N). The validation against the eco-hydrological wireless sensor network observations and artificial synchronized observation shows that the total accuracy of this dataset can achieve 0.05 cm^3/cm^3, and that of the products on 7 July and 10 July even less than 0.04 cm^3/cm^3. This dataset can be helpful for the land surface process/hydrological process simulation and data assimilation, surface flux estimation, artificial irrigation management and spatial scaling research.

The dataset of ground truth measurements synchronizing with the airborne WiDAS mission was obtained in the Linze station foci experimental area on May 30, 2008. WiDAS, composed of four CCD cameras, one mid-infrared thermal imager (AGEMA 550), and one infrared thermal imager (S60), can acquire CCD, MIR and TIR band data. The simultaneous ground data included: (1) soil moisture (0-5cm) measured nine times by the cutting ring method (50cm^3) along LY07 and LY08 quadrates, and once by the cutting ring method and once by ML2X Soil Moisture Tachometer in the six points of Wulidun farmland quadrates. The preprocessed soil volumetric moisture data were archived as Excel files. (2) surface radiative temperature measured by two handheld infrared thermometer (5# and 6# from Cold and Arid Regions Environmental and Engineering Research Institute which were both calibrated) in the LY07 and LY08 quadrates (98 sample points and repeated three times) and the Wulidun farmland quadrates (various points and repeated three times). Data were archived as Excel files. (3) spectrum of maize, soil and soil with known moisture measured by ASD Spectroradiometer (350～2 500 nm) from BNU,and the 40% reference board in Wulidun farmland quadrate and the desert transit zone strips. Raw spectral data were archived as binary files, which were recorded daily in detail, and pre-processed data on reflectance were archived as Excel files. (4) maize BRDF measured by ASD Spectroradiometer (350～2 500 nm) from BNU, the 40% reference board, two observation platforms of BNU make and one of Institute of Remote Sensing Applications make in Wulidun farmland quadrate and the desert transit zone strips. Raw spectral data were archived as binary files , which were recorded daily in detail, and pre-processed data on reflectance and transmittivity (read by ViewSpecPro) were archived as text files (.txt). (5) LAI of maize, poplar and the desert scrub measured by the fisheye camera (CANON EOS40D with a lens of EF15/28), shooting straight downwards, with exceptions of higher plants, which were shot upwards in Wulidun farmland quadrate I, the desert transit zone and the poplar forest. Data included original photos (.JPG) and those processed by can_eye5.0 (in excel). (6) LAI measured by the ruler and the set square in D and H quadrates of the Wulidun farmland. Part of the samples were also measured by LI-3100 and compared with those by manual work for further correction. 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.