Current Browsing: Depth of Soil Freezing


WATER: Dataset of ground truth measurements synchronizing with Landsat TM in the Biandukou foci experimental area (Mar. 17, 2008)

The dataset of ground truth measurements synchronizing with Landsat TM was obtained in the Biandukou foci experimental area from 11:10-13:30 on Mar. 17, 2008. Those provide reliable ground data for objects modelling and background modelling, remote sensing image simulation and scaling. Simultaneous with the satellite overpass, numerous ground data were collected, spectrum (ASD Fieldspec FRTM (Boulder, Co, USA), 350nm-2500nm, 3nm for the visible near-infrared band and 10nm for the shortwave infrared band), the surface temperature, atmospheric parameters, the soil profile gravimetric moisture (0-1cm, 1-3cm and 3-5cm), the shallow layer frost depth and the soil roughness in C1, G1, W1, W2, B1 and B2, mostly the grassland, the wheat stubble land, the deep plowed land and the rape stubble land. The quadrates of 90m×90m and 450m×450m were compartmentalized into 81 subgrids of 10m×10m and 50m×50m. Based on the resolution of 30m×30m and 150m×150m, the influence of adjacent eight pixels on the center pixel was studied. Section lines of each subgrid were adopted to acquire the pixel spectrum, which were measured more than once for the mean value. The spectrum data were archived in the ASCII format, with the first five rows as the file header and the following two columns as wavelength (nm) and reflectance (percentage) respectively. The .txt file was not reflectance but intermediate file for further calculation. Raw data were binary files direct from ASD (by ViewSpecPro). The surface radiative temperature and the physical temperature were measured by the handheld infrared thermometer. Besides, the cover type was also recorded. The data can be opened by Microsoft Office. Atmospheric parameters were measured by CE318 to retrieve the total optical depth, aerosol optical depth, Rayleigh scattering coefficient, column water vapor in 936 nm, and various parameters at 550nm to obtain horizontal visibility with the help of MODTRAN or 6S. Those provide reliable data for atmosphere correction of the same period in this area. The gravimetric soil moisture (samples from 0-1cm, 1-3cm and 3-5cm) was measured by the microwave drying method. 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. Nine data files were included, TM data, CE318 data, B1, B2, C1, G1, W1 and W2.

2019-09-13

WATER: Dataset of ground truth measurement synchronizing with the airborne microwave radiometers (L&K bands) mission in the Biandukou foci experimental area on Mar. 19, 2008

The dataset of ground truth measurement synchronizing with the airborne microwave radiometers (L&K bands) was obtained in the Biandukou foci experimental area from 11:20 to 12:30BJT on Mar. 19, 2008. Observation items included: (1) 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 Word. (2) the surface radiative temperature by the handheld infrared thermometer and the physical temperature by the thermocouple. The data can be opened by Microsoft Office Word. (3) the soil moisture (soil samples from 0-1cm, 1-3cm and 3-5cm) by the microwave drying method. The data can be opened by Microsoft Office Word. (4) photos of each sampling point in .jpg for further reference. Six data files were included, the ground-based K-band microwave radiometer, the ground-based L-band microwave radiometer, the frost depth, soil moisture, the surface temperature and the surface conditions.

2019-05-23

WATER: Dataset of ground truth measurement synchronizing with MODIS in the Biandukou foci experimental area on Mar. 12, 2008

The dataset of ground truth measurement synchronizing with MODIS was obtained in C1, G1 and B2 of the Biandukou foci experimental area on Mar. 12, 2008. Observation items included: (1) the surface temperature by the handheld infrared thermometer in C1, G1 and B2 from 11:30 to 12:15. The underlying surface was the deep plowed land, the rape stubble and the grassland. (2) the gravimetric soil moisture (soil samples from 0-1cm, 1-3cm, 3-5cm, 5-10cm and 10-20cm) 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 land cover type photos were archived. Four data files were archived, MODIS data, C1 (the land cover type, the surface temperature and the vegetation parameters), G1 ( the surface temperature, the frost depth and the soil moisture) and B2 (the surface temperature, the frost depth and the soil moisture) data.

2019-05-23

WATER: Dataset of the ground-based microwave radiometers and ground truth observations for soil freeze/thaw cycle in the A'rou foci experimental area

The dataset of the ground-based microwave radiometers and ground truth observations for soil freeze/thaw cycle was obtained in the A'rou foci experimental area (N38º03.639'/E100º26.793'; 2998m) from May 5 to 8, 2008, S-band from Apr. 6 to 8, C-band from Apr. 7 to 8, K-band from Apr. 5 to 8, and Ka-band on Apr. 5, to be specific. The aims of the measurements were the effects of the soil freeze/thaw status on the microwave brightness temperatures. The observation site was bare land and the soil moisture was 30% after artificial irrigation. Observation items included the soil temperature at 5cm automatically (the time interval: 10m), the soil temperature at 5cm, 10cm, 20cm and 30cm by the probe thermometer (the time interval: 1h), and the soil moisture at 5cm, 10cm, 20cm and 30cm automatically (the time interval: 10m). Seven files were included, four ground-based microwave radiometers (S-band, C-band, K-band and Ka-band) observations, the automatic soil temperature, the manual soil temperature, and the automatic soil moisture, and the last three were archived in Excel format.

2019-05-23

WATER: Dataset of ground truth measurement synchronizing with the airborne microwave radiometers (L&K bands) mission in the Biandukou foci experimental area on Mar. 21, 2008

The dataset of ground truth measurement synchronizing with the airborne microwave radiometers (L&K bands) mission was obtained in the Biandukou foci experimental area from 8:25 to 11:15 BJT on Mar. 21, 2008. Observation items included: (1) microwave radiometer observations; (2) the surface radiative temperature by the handheld infrared thermometer and the physical temperature by the thermocouple thermometer; (3) the frost depth by the chopstick and the ruler. The soil was considered frozen when it was hard and with ice crystal; (4) Snow depth by the ruler; (5) the gravimetric soil moisture (soil samples from 0-1cm, 1-3cm and 3-5cm) by the microwave drying method. The volumetric moisture can be calculated by the gravimetric moisture and bulk density. The data can be opened by Microsoft Office. The sample point coordinates were also included.

2019-05-23

WATER: Dataset of soil frozen penetration measured by the soil frozen tube at the super site around the Dayekou Guantan forest station

The dataset of soil frozen penetration measured by the soil frozen tube was obtained at the super site (100m×100m, pure Qinghai spruce) around the Dayekou Guantan forest station. Observation time was 8:00 each morning from Jun. 1 to Dec. 31, 2008. The soil frozen tube was laid beneath the spruce for diurnal soil frozen depth changes and the maximum depth (cm) was recorded.

2019-05-23

WATER: Dataset of ground truth measurements synchronizing with MODIS in the Biandukou foci experimental area on Mar. 14, 2008

The dataset of ground truth measurements synchronizing with MODIS was obtained in C1, W2 and B2 of the Biandukou foci experimental area from 12:00-15:00 on Mar. 14, 2008. Observation items included: (1) the frost depth from 11:37-12:11 by the chopstick and the ruler. The soil was considered frozen when it was hard and with ice crystal. The cover type photos were archived. (2) the gravimetric soil moisture (soil samples from 0-1cm, 1-3cm, 3-5cm, 5-10cm and 10-20cm) by the microwave drying method. (3) the surface radiative temperature by the handheld infrared thermometer and the physical temperature by the thermocouple thermometer. (4) the soil roughness, which can be acquired from related dataset of other period.

2019-05-23

WATER: Dataset of ground-based RPG-8CH-DP microwave radiometer and ground truth observations for soil freeze/thaw cycle in the A'rou foci experimental area

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.

2019-05-23

WATER: Dataset of the ground-based microwave radiometers and ground truth observations for soil freeze/thaw cycle in the A'rou foci experimental during the pre-observation period

The dataset of the ground-based microwave radiometers and ground truth observations (multi-frequency, multi-polar multi-angle) for soil freeze/thaw cycle in the A'rou foci experimental area from Oct. 19 to 25, 2007, during the pre-observation period, X-band from Oct. 20 to 25, S-band from Oct. 20 to 25, K-band from Oct. 19 to 24, and Ka-band from Oct. 20 to 24, to be specific. The aims of the measurements were the effects of the soil freeze/thaw status on the microwave brightness temperatures. Those provide reliable ground data for improving and verifying microwave radiative transfer models and parameters retrieval of soil freeze/thaw status. Time-continuous ground observations synchronizing with the ground-based microwave radiometers including self-recording and manual measurements, were carried out in No. 1 quadrate of A'rou with dry natural grassland as the landscape. (1) self-recording observations: the soil temperatures at 0cm, 5cm, 10cm, 15cm and 20cm by the temperature probe from Oct. 21 to 25, 2007, and shallow layer soil moisture at 0-5cm, 5cm, 10cm, 15cm and 20cm by TDR from Oct. 19 to 21 2007. Both time interval of the observations were 5 minutes. (2) manual observations: the surface radiative temperature by the handheld infrared thermometer, the soil temperature at 0cm, 5cm, 10cm, 15cm and 20cm by the glass geothermometer, and the mean soil temperature from 0-5cm by the probe thermometer. The time interval of observations was 30 minutes from Oct. 19-21, 2007.

2019-05-23

WATER: Dataset of ground truth measurements synchronizing with Envisat ASAR in the A'rou foci experimental areas on Mar. 12, 2008

The dataset of ground truth measurements synchronizing with Envisat ASAR was obtained in No.1 (freeze/thaw status), No. 2 (snow parameters) and No. 3 (freeze/thaw status) quadrates of the A'rou foci experimental areas on Mar. 12, 2008. The Envisat ASAR data were in AP mode and VV/VH polarization combinations, and the overpass time was approximately at 11:29 BJT. The quadrates were divided into 4×4 subsites, with each one spanning a 30×30 m2 plot. Center and corner points of each subsite were chosen for all observations except for the cutting ring measurements which only observed the center points. In No. 1 quadrate, 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 soil volumetric moisture profile (10cm, 20cm, 30cm, 40cm, 60cm and 100cm) by PR2, the mean soil temperature from 0-5cm by the probe thermometer, soil gravimetric moisture, volumetric moisture, and soil bulk density after drying by the cutting ring (100cm^3). In No. 2 quadrate, simultaneous with ASAR, snow parameters were measured, the snow surface temperature by the thermal infrared probe, the snow layer temperature by the probe thermometer, the snow grain size by the handheld microscope, snow density by the aluminum case, the snow surface temperature and the snow-soil interface temperature by the thermal infrared probe, snow spectrum by ASD, and snow albedo by the total radiometer. In No. 3 quadrate soil volumetric moisture, soil conductivity, the soil temperature, and the real part of soil complex permittivity were measured by WET, the mean soil temperature from 0-5cm by the probe thermometer (5# and 7#), the surface radiative temperature by the hand-held infrared thermometer (5#), and 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". Besides, GPR (Ground Penetration Radar) observations were also carried out in No. 1 quadrate of A'rou. Those provide reliable ground data for retrieval and verification of soil moisture and freeze/thaw status from active remote sensing approaches.

2019-05-23