On 25 July 2012, a Leica ALS70 airborne laser scanner boarded on the Y-12 aircraft was used to obtain the point cloud data. Leica ALS70 airborne laser scanner has unlimited numbers of returns intensities measurements including the first, second, third return intensities. The wavelength of laser light is 1064 nm. The absolute flight altitude is 5500 m with the point cloud density 1 points per square meter. Aerial LiDAR- DSM was obtained through parameter calibration, automatic classification of point cloud density and manual editing.
2019-05-23
The dataset of soil moisture profile observations was obtained (once every ten days) in the Pailugou watershed foci experimental area during 2007 and from May to Sep. 2008. The soil profile was the moss litter layer, 0-10cm, 10-20cm, 20-40cm, 40-60cm and 60-80cm. It was fetched by the cutting ring and was measured through oven drying. Land cover types included spruce forest located in different elevation levels of 2600m, 2700m, 2900m, 3100m and 3300m, scrub of 3300m, 3400m and 3500m, and tailo grassland of 2600m, 2700m, 2800m and 2900m. Data were archived in Excel format.
2019-05-23
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 Jul. 4, 2008. Observation items included: (1) the soil temperature by the handheld infrared thermometer from L1 to L8 (1km from one another) in Biandukou and soil moisture by ML2X; nine samples were collected every 200 m along each line (1.6km). (2) 5 quadrates (50cm×50cm) investigations including GPS, the vegetation cover types and the height, the actual numbering, the valve bag numbering, wet weight+the refuse bag (g), dry weight+the envelope (g), the envelope (g) and the photo numbering. The data were archived as Excel files.
2019-05-23
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.
2019-05-23
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.
2019-05-23
The dataset of ground truth measurements for snow was obtained, synchronizing with airborne microwave radiometers (K&Ka bands) mission in the Binggou watershed foci experimental area on Mar. 29, 2008. Those provide reliable ground data for retrieval of snow properties and parameters, especially snow depth and snow water equivalent study. Observation items include (1) snow density, snow complex permittivity, snow volumetric moisture and snow gravimetric moisture by the snowfork in BG-A; (2) snow parameters in BG-A (18 points), BG-B (20 points), BG-EF (20 points) and BG-I (20 points): snow depth by the ruler, the snow temperature (mean of two measurements) by the probe thermometer, snow grain size by the handheld microscope, snow density by the cutting ring for each snow layer, and the snow surface temperature and the snow-soil interface temperature by the handheld infrared thermometer. For each snow pit, the snowpack was divided into several layers with 10-cm intervals of snow depth. Two files including raw data and pre-processed data were archived.
2019-05-23
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.
2019-05-23
The dataset of soil moisture observations (VWC%) was obtained at the super site (100m×100m) around the Dayekou Guantan forest station on Jun. 5, 2008. The super site was divided into 16 subplots (25m×25m). 10 points were measured by TDR 300 (with the probe 20cm long) at random location in each subplot. The serial number and the cover type of the subplot, the number of the sample points and soil moisture (%) were recorded. Those provide reliable data for the construction of the 3D structure of the forest scene, and for the modeling of active and passive remote sensing mechanisms and the simulation of remote sensing images.
2019-05-23
The dataset of water content of forest canopy components (the twig and the leaf) measurements was obtained at the super site (100m×100m) around the Dayekou Guantan forest station on Jun. 5, 2008. The sample tree was selected according to different diameters at breast height. 5 diameter classes were divided and in each class, 10 trees were selected and altogether 30 trees were selected as sampling trees. Branches in different parts were picked by the tree pruner and the twig and the leaf were separated manually, whose green weight was measured by the scales on the scene and dry weight by oven drying in the lab. Those provide reliable data for the reconstruction of the 3D structure of the forest scene, and for modelling active and passive remote sensing mechanisms and the simulation of remote sensing images.
2019-05-23
The dataset of ground truth measurements synchronizing with Envisat ASAR was obtained in the Linze station foci experimental area from Sep. 12 to Sep. 15, 2007 during the pre-observation period. One scene of Envisat ASAR image was captured on Sep. 19. The data were in AP mode and VV/VH polarization combinations, and the overpass time was approximately at 11:29 BJT. Observation items included: (1) GPS by GARMIN GPS 76 (2) LAI by LAI-2000 (3) photosynthesis measured by LI6400 from Linze station carried out according to WATER specifications. Raw data were archived in the user-defined format , which can be opened by notepat and processed by Excel. (4) object spectrum of typical ground objects measured by ASD FieldSpec Spectroradiometer (350～2 500 nm) from Gansu Meteorological Administration. The reference whiteboard was attached therein. Raw spectral data were archived as binary files, which were recorded daily in detail, and pre-processed data on reflectance were archived as text files (.txt). (5) infrared temperature measured by the handheld infrared thermometer from Cold and Arid Regions Environmental and Engineering Research Institute, which was calibrated. The infrared temperature of the crown, the vertical canopy, 45 degrees frontlight and backlight were measured respectively. The data were archived as Excel files. (6) soil profile (0-10cm, 10-20cm, 20-40cm and 40-60cm), and soil moisture measured by the cutting ring method. Profile photos were taken meanwhile. (7) quadrate (1m×1m) investigations, including the quadrate number, species, quantities, coverage, the total quadrate coverage, the mean height, biomass number, the total green weight and the total dry weight. (8) repeated measurements on chlorophyll content of different species measured by SPAD 502. (9) photos taken by Nikon D80 with a lens of Sigma 8mm F3.5 EX DG CIRCULAR FISHEYE, shooting straight downwards at the height of 1.5m (10) atmospheric parameters at Daman Water Management office measured 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 and can be opened by ASTPWin. ReadMetext files (.txt) is attached for detail. Processed data (after retrieval of the raw data) in Excel 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.
2019-05-23
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