Current Browsing: visible remote sensing


WATER: Dataset of ground truth measurement synchronizing with the airborne WiDAS mission and Envisat ASAR in the Linze station foci experimental area on July 11, 2008

The dataset of ground truth measurement synchronizing with the airborne WiDAS mission and Envisat ASAR was obtained in the Linze station foci experimental area on Jul. 11, 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 data were in AP mode and VV/VH polarization combinations, and the overpass time was approximately at 11:26 BJT. The simultaneous ground data included the following items: (1) soil moisture (0-5cm) measured once by the cutting ring method at the corner points of the 40 subplots of the west-east desert transit zone strip , once by the cutting ring method in the nine subplots of the north-south desert transit zone, nine times in the LY06 and LY07 strips quadrates,and once by the cutting ring and once by ML2X Soil Moisture Tachometer in the Wulidun farmland. The preprocessed soil volumetric moisture data were archived as Excel files. (2) the surface radiative temperature measured by three handheld infrared thermometer (5# and 6# from Cold and Arid Regions Environmental and Engineering Research Institute, and one from Institute of Geographic Sciences and Natural Resources, which were all calibrated) in LY06 and LY07 strips (49 points and repeated three times), and 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 reference board (40% before Jun. 15 and 20% hereafter) in Wulidun farmland. Raw spectral data were binary files , which were recorded daily in detail, and pre-processed data on reflectance (by ViewSpecPro) were archived as Excel files. (4) maize BRDF measured by ASD Spectroradiometer (350~2 500 nm) from BNU, the reference board (40% before Jun. 15 and 20% hereafter), two observation platforms of BNU make and one of Institute of Remote Sensing Applications make in Wulidun farmland. Raw spectral data were archived as binary files, which were recorded daily in detail, and pre-processed data on reflectance and transmittivity were archived as text files (.txt). (5) LAI measured in the maize quadrate, poplar quadrate and desert scrub quadrate in Wulidun farmland, the desert transit zone strips and the poplar forest quadrate by the fisheye camera (CANON EOS40D with a lens of EF15/28), shooting straight downwards, with exceptions of higher plants, which were shot upwards. Data included original photos (.JPG) and those processed by can_eye5.0 (in excel). (6) LAI of maize measured by LAI2000 in Linze station quadrates and Wulidun farmland quadrates. Data educed from LAI2000 periodically were archived as text files (.txt) and marked with one ID. Raw data (table of word and txt) and processed data (Excel) were included. Besides, observation time, the observation method and the repetition were all archived. (7) LAI measured by the ruler and the set square in B2 and B3 of Linze station quadrates. 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.

2019-09-12

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.

2019-09-12

SRAP AOD dataset of Asia (2002-2011)

The “China Collection 1.0" aerosol optical depth (AOD) data set was produced using visible light wave remote sensing inversion. The raw data come from the MODIS sensors on Terra and Aqua. The temporal coverage of the data is from 2002 to 2011, the temporal resolution is daily, the spatial coverage is the Asian continent, and the spatial resolution is 0.1°. The remote sensing inversion method uses the independently developed SRAP algorithm to invert the aerosol optical depth over the land. The algorithm takes the BRDF characteristics of the surface into consideration, which makes it applicable to aerosol optical depth inversion on bright and dark surfaces. In addition, aerosol products over the ocean of MOD04/MYD04 are superimposed. The verification of the measured site shows that the relative deviation of the aerosol optical depth data in Asia is within 20%. The data are stored as an hdf file each day, each consisting of Terra AOD and Aqua AOD at 550 nm.

2019-09-12

WATER: Dataset of ground truth measurement synchronizing with PROBA CHRIS in the A'rou foci experimental area on Jun. 23, 2008

The dataset of ground truth measurement synchronizing with PROBA CHRIS was obtained in No. 2 and 3 quadrates of the A'rou foci experimental area on Jun. 23, 2008. Observation items included: (1) quadrates investigation including GPS by GARMIN GPS 76, plant species by manual cognition, the plant number by manual work, the height by the measuring tape repeated 4-5 times, phenology by manual work, the coverage by manual work (compartmentalizing 0.5m×0.5m into 100 to see the percentage the stellera takes) and the chlorophyll content by SPAD 502. Data were archived in Excel format. (2) roughness by the self-made roughness board and the camera. The processed data were archived as .txt files. (3) BRDF by ASD FieldSpec (350~2 500 nm), with 20% reference board and the observation platform made by Beijing Normal University. The processed reflectance and transmittivity were archived as .txt files. (4) LAI of stellera and pasture by the fisheye camera (CANON EOS40D with a lens of EF15/28), shooting straight downwards, with exceptions of higher plants, which were shot upwards. Data included original photos (.JPG) and those processed by can_eye5.0 (in Excel). For more details, see Readme file. Five files were included, spectrum in No.2 quadrate, multiangle observations in No.2 and 3 quadrates, roughness photos in No.2 and 3 quadrates, the fisheye camera observations, and the No.2 and 3 quadrates investigation.

2019-09-12

WATER: Dataset of ground truth measurements synchronizing with Landsat TM in the Linze grassland and Linze station foci experimental area during the pre-observation period (on Sep. 23, 2007)

The dataset of ground truth measurements synchronizing with Landsat TM was obtained in the Linze grassland and Linze station foci experimental area on Sep. 23, 2007 during the pre-observation periods, and one scene was captured well. These data can provide reliable ground data for retrieval and validation of land surface temperatures with EO-1 Hyperion remote sensing approaches. Observation items included: (1) the land surface radiative temperature by the hand-held infrared thermometer, which was calibrated; (2) GPS by GARMIN GPS 76; (3) 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. These data include the raw data in .k7 format and can be opened by ASTPWin software. ReadMe.txt is attached for detail. Processed data (after retrieval of the raw data) in Excel contain 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. (4) ground-based land surface temperature measurements by the thermal imager in the Heihe gobi, west of Zhangye city.

2019-09-12

WATER: BJ-1 dataset

BJ-1 dataset includes 11 scenes, covering the upper and middle reaches of the Heihe river basin, which were acquired on 10-21-2007, 11-19-2007, 01-09-2008, 03-03-2008, 04-04-2008, 04-16-2008, 05-01-2008, 05-16-2008, 07-01-2008, 07-06-2008 and 07-08-2008. The sensor was MSI, substar resolution was 32m, fov was 22.06°, the orbit was 686km high and the dip angle was 98.1725°, the focal distance was 150mm, CCD pixel was 7μm, the near infrared band was 760nm-900nm, red wave band was 630nm-690nm and green wave band was 520nm-620nm. The data version is Level 2, which was released after geometric correction. BJ-1 dataset was acquired from "Dragon Programme" (grant number: 5322).

2019-09-12

WATER: Dataset of ground truth measurement synchronizing with the airborne LiDAR mission and Envisat ASAR in the Yingke oasis and Huazhaizi desert steppe foci experimental areas (Jun. 19, 2008)

The dataset of ground truth measurement synchronizing with the airborne LiDAR mission and Envisat ASAR was obtained in the Yingke oasis and Huazhaizi desert steppe foci experimental areas on Jun. 19, 2008. The Envisat ASAR data were in AP mode and VV/VH polarization combinations, and the overpass time was approximately at 11:17 (Beijing Time). The observation item was soil moisture by TDR ( the probe with a length of 5cm) in the maize plot of Yingke oasis station, the wheat plot and some temporary sample points (details in GPS.txt).

2019-09-12

WATER: Dataset of ground truth measurements synchronizing with PROBA CHRIS in the Biandukou foci experimental area on Jul. 18, 2008

The dataset of ground truth measurements synchronizing with PROBA CHRIS was obtained in 21 quadrates of the Biandukou foci experimental area on Jul. 18, 2008. Observation items included: (1) GPS by GARMIN GPS 76; (2) species by manual cognition; (3) the plant number by manual work, (4) the height by the measuring tape repeated 4-5 times, (5) the chlorophyll content by SPAD 502; (6) the coverage by manual work; (7) photo taking by Nikon D80 with a lens of Sigma 8mm F3.5 EX DG CIRCULAR FISHEYE, shooting straight downwards at the height of 1.5m; original photos were in JPG format and the processed data in Excel format. (8) the biomass (samples over 0.5m×0.5m) by wet weight and dry weight; as Excel files.

2019-09-11

WATER: Dataset of ground truth measurement synchronizing with MODIS in the Linze grassland foci experimental area on June 22, 2008

The dataset of ground truth measurement synchronizing with MODIS was obtained in the Linze grassland foci experimental area on Jun. 22, 2008. Simultaneous east-west ground measurements on the canopy temperature, the half-height temperature and the land 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) on Jun. 22, No.2 quadrate (H09-H16) on Jun. 23,No.3 quadrate (H17-H24) on Jun. 22, No.4 quadrat (H25-H32) on Jun. 23, No.5 quadrate (H33-H40) on Jun. 22, No.6 quadrate (H41-H48) on Jun. 23, No,7 quadrate (H49-H56) and No.8 quadrate (H57-H64) on Jun. 23. Data were archived in Excel format. See WATER: Dataset of setting of the sampling plots and stripes in the foci experimental area of Linze station for more information.

2019-09-11

Lake surface area dynamics on the Tibetan Plateau (Version 1.0) (1984-2016)

The data set of lake dynamics on the Tibetan Plateau was mainly derived from Landsat remote sensing data. Band ratio and the threshold segmentation method were applied. The temporal coverage of the data set was from 1984 to 2016, with a temporal resolution of 5 years. It covered the whole Tibetan Plateau at a spatial resolution of 30 meters. The water body area extraction method mainly adopted the band ratio (B4/B2) or water body index to construct the classification tree. The algorithm construction considered the spatial and temporal variations of the spectral characteristics of the water body and adjusted the threshold of the decision tree by the slope and the slope aspect information of the water body. The long-term sequence satellite-borne data came from different sensors, e.g., Landsat MSS, TM, ETM+, and OLI. The minimum unit for extracting water body information was 2*2 pixels, and all water body areas less than 0.36*10^-2 Km² were removed. The water body information extracted by high-resolution remote sensing data and the verification of the water body checkpoint determined by visual interpretation indicated that the overall accuracy of the water body area information for the Tibetan Plateau was above 95%. The data were saved as a shape file, and projected by Albers projection, with a central meridian of 105 ° and a double standard latitude of 25 ° and 47 °.

2019-05-30