The phased array type l-land synthetic aperture radar (PALSAR) is a phased array L-band SAR sensor mounted on alos satellite. The sensor has three observation modes: high resolution, scanning synthetic aperture radar and polarization, which make it possible to obtain a wider ground width than the general SAR. At present, there are 13 scenes of ALOS pallsar data in Heihe River Basin. The coverage and acquisition time are as follows: 1 scene in the northeast of Zhangye City, HH / HV polarization, 2008-04-25; 2 scenes in Binggou basin + Arjun encrypted observation area, HH / HV polarization, 2008-05-122008-06-27; 2 scenes in Dayekou basin + Yingke oasis intensified observation area, HH / HV polarization, 2008-05-122008-06-27; observation station encrypted observation area Survey area + Linze station densified observation area + Linze grassland densified observation area 2 scenes, HH / HV polarization, time 2008-05-122008-06-27; Linze station densified observation area 1 scene, HH / HV polarization, time 2008-05-12; Binggou basin densified observation area 1 scene, HH / HV polarization, time 2008-07-14; bindukou densified observation area 4 scenes, 2008-04-25 2 scenes, HH / HV polarization, 2008-06-10 2 scenes, HH pole Change. The product level is L1 without geometric correction. The alos PALSAR remote sensing data set of Heihe comprehensive remote sensing joint experiment was obtained from JAXA by Dr. Takeo tadono, researcher Ye Qinghua and Professor Shi Jiancheng (the cooperation project between Qinghai Tibet Institute of Chinese Academy of Sciences and JAXA). (Note: "+" means to overwrite at the same time)
The dataset of soil moisture observations was obtained by the cutting ring (50cm^3) and ML2X Soil Moisture Tachometer in the Linze station foci experimental area. Surface soil (0-5cm) was measured 2-3 times in 40 subplots of the west-east desert strip on May 24, 25, 28, Jun. 27 and Jul. 11, 2008, 2-4 times in 9 subplots of north-south strip on May 24, 25, 28, Jun. 27 and Jul. 11, 17 times from P1 to P6 strips on Jul. 4 and 8, nine times along LY06 strip on Jun. 6, 15, 29 and Jul. 11, LY07 strip on May 30, Jun. 6, 10, 15, 29 and Jul. 11 and LY08 strip on May 30, Jun. 6 and 10, and once by the cutting ring and three times by ML2X Soil Moisture Tachometer in Wulidun farmland quadrates on May 24, 25, 28, Jun. 29 and Jul. 11. 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 vegetation cover fraction observations was obtained by the self-made instrument and the camera at a height of 2.5m-3.5m above the ground in the Yingke oasis, Huazhaizi desert steppe and Biandukou foci experimental areas on May 20, 24, 25, 28 and 30, Jun. 11, 14, 15, 21, 23, 24, 27 and 30, and Jul. 2, 2008. Observations were carried out in Yingke oasis maize field, Yingke oasis wheat field, Huazhaizi desert No. 1 and 2 plots, the rape field, the barley field and grassland in Biandukou. A pole with known length was put in each photo to determine the size of the photo. GPS data was used for the location and the technology LAB was used to retieve the coverage of the green vegetation. Besides, surrounding environment was also recorded. The dataset included the primary collected vegetation images and retrieved fraction of vegetation coverage.
The dataset of LAI measurements was obtained by LI-3000, the protractor and the ruler in the Yingke oasis and Huazhaizi desert steppe foci experimental areas on May, 20, 24, 25, 28 and 31, Jun. 6, 11, 12, 14, 16, 21 and 27, Jul. 2 and 9, 2008. The maximum leaf length and width of maize and wheat, the leaf angle, length and width of each section (one leaf was divided into 3 sections) were measured. And also the plant height, leaf base height, the crop spacing, the canopy height, row spacing and ridge spacing were measured. Two representative plants would be taken back for indoor observation for the stem length, stem width, stem circumference, and leaf area by LAI3000. Data were archived in Excel format.
The dataset of ground truth measurement synchronizing with ALOS PALSAR was obtained in the Linze grassland 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. Observations were carried out in the reed plot A, the saline plot B, the alfalfa plot D and the barley plot E, which were divided into 6×6 subsites, with each one spanning a 120×120 m2 plot. Soil gravimetric moisture, volumetric moisture, and soil bulk density after drying by the cutting ring and the mean soil temperature from 0-5cm by the probe thermometer were measured in A and B; 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 soil gravimetric moisture, volumetric moisture, and soil bulk density after drying by the cutting ring in D and E. 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 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 albedo observations was obtained by the shortwave radiometer (1#: CMP3-060580 and 2#: CMP3-060584 from Institute of Remote Sensing Applications) in the arid region hydrology experiment area from May 20 to Jul. 14, 2008. The dataset of ground truth measurement was synchronizing with WiDAS (Wide-angle Infrared Dual-mode line/area Array Scanner), OMIS-II, Landsat TM, ASTER, Hyperion and CHRIS. Observation items included: (1) Albedo in Yingke oasis and Huazhaizi desert steppe foci experimental area. Yingke maize field was measured on May 28 and 30, Jun. 3, 16, 20, 27 and 29, Jul. 11 and 14, 2008, Yingke wheat field on May 20 and 29, Jun. 1, 4, 6, 9, 15 and 24, Jul. 7 and 14, 2008, Huazhaizi desert No. 2 plot on Jun. 14, 22 and 30, 2008 and the flax field on Jun. 23, 2008. (2) Albedo in Linze foci experimental area. Maize was measured on May 25, 2008 and desert and alfalfa on May 24, 2008. (3) Albedo in Biandukou foci experimental area. The rape field, the grassland and the barley were measured on Jun. 24, 2008, and barley on Jul. 6, 2008. (4) Zhangye intensive experimental area. The intra-city grassland and the roof of Jingdu Hotel were measured on May 27, 2008. Besides the shortwave radiometer, the digital multimeter (UNIT) was also used for voltage measuring. Raw data were archived in paper forms and Excel after input into the computer. Besides, shorter plants were chosen for measurements as the platform was not high enough. And the distance between the probe and the plant was shorter during the later observation period.
The dataset of sun photometer observations was obtained in the Yingke oasis and Huazhaizi desert steppe foci experimental areas. 24 times observations were carried out by CE318 from BNU (at 1020nm, 936nm, 870nm, 670nm and 440nm, and column water vapor by 936 nm data) and from Institute of Remote Sensing Applications, CAS (at 1640nm, 1020nm, 936nm, 870nm, 670nm, 550nm, 440nm, 380nm and 340nm, and column water vapor by 936 nm data) on May 20, 23, 25 and 27, Jun. 4, 6, 16, 20, 22, 23, 27 and 29, Jul. 1, 7 and 11, 2008. Those atmospheric measurements synchronized with airborne (i.e. WiDAS, OMIS) and spaceborne sensors (i.e. TM, ASTER,CHRIS and Hyperion) 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 empiricism, which was not reliable. For more accurate result, simultaneous data from the weather station are needed. (2) Errors from instrument calibration parameters. Field calibration based on Langly or interior instrument calibrationcin 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 empiricism, and need further checking. Raw data were archived in k7 format and can be opened by ASTPWin. ReadMe.txt is attached for details. 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 parts are included in CE318 result data (see Geometric Positions and the Total Optical Depth of Each Channel and Rayleigh Scattering and Aerosol Optical Depth of Each Channel).