Current Browsing: Remote Sensing Technology


HiWATER: Airborne LiDAR raw data in the sample strip of the Heihe River Basin

On 25 August 2012, Leica ALS70 airborne laser scanner carried by the Harbin Y-12 aircraft was used in a LiDAR airborne optical remote sensing experiment. 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 5200 m with the point cloud density 1 point per square meter. Airborne LiDAR-DEM and DSM data production were obtained through parameter calibration, automatic classification of point cloud density and manual editing.

2019-05-23

HiWATER: Airborne LiDAR raw data in the middle reaches of the Heihe River Basin

On 19 July 2012, Leica ALS70 airborne laser scanner carried by the Harbin Y-12 aircraft was used in a LiDAR airborne optical remote sensing experiment. 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 relative flight altitude is 1500 m (the elevation of 2700 m) with the point cloud density 4 points per square meter. Airborne LiDAR-DEM and DSM data production were obtained through parameter calibration, automatic classification of point cloud density and manual editing.

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 May 25, 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 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

HiWATER: Dataset of airborne microwave radiometers (L bands) mission in the upper reaches of the Heihe River Basin on 1 August, 2012

The dataset of airborne Polarimetric L-band Multibeam Radiometers (PLMR) was acquired on 1 August, 2012, located in the upper reaches of the Heihe River Basin. The aircraft took off at 8:30 am (UTC+8) from Zhangye airport and landed at 12:30 pm, with the flight time of 4 hours. The flight was performed in the altitude of about 1000 m and at the speed of about 220-250 km during the observation, corresponding to an expected ground resolution of about 300 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.

2019-05-23

HiWATER: Dataset of airborne microwave radiometers (L bands) mission along the riverway of Heihe River in the middle reaches of the Heihe River Basin on 3 July, 2012

The dataset of airborne Polarimetric L-band Multibeam Radiometers (PLMR) was acquired on 3 July, 2012, located along the riverway of Heihe River in the middle reaches of the Heihe River Basin. The aircraft took off at 11:40 am (UTC+8) from Zhangye airport and landed at 14:10 pm, with the flight time of 2.5 hours. The flight was performed in the altitude of about 350 m and at the speed of about 220-250 km during the observation, corresponding to an expected ground resolution of about 100 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.

2019-05-23

HiWATER: Dataset of airborne microwave radiometers (L bands) mission in the middle reaches of the Heihe River Basin on 5 July, 2012

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.

2019-05-23

HiWATER: Airborne CCD image data in Tianlaochi Catchment

On 25 August 2012, a RCD30 camera of Leica Company boarded on the Y-12 aircraft was used to obtain the CCD image. RCD30 camera has a focal length of 80 mm and four bands including red, green, blue and near-infrared bands. The absolute flight altitude is 4800 m and 5200 m, and ground sample distance is 8-19 cm. The product includes TIF images and exterior orientation elements.

2019-05-23

WATER: Dataset of ground truth measurements for snow synchronizing with EO-1 Hyperion and Landsat TM in the Binggou watershed foci experimental area on Mar. 17, 2008

The dataset of ground truth measurements for snow synchronizing with EO-1 Hyperion and Landsat TM was obtained in the Binggou watershed foci experimental area on Mar. 17, 2008. Observation items included: (1) Snow parameters as snow depth by the ruler, the snow layer temperature by the probe thermometer, the snow grain size by the handheld microscope, the snow surface temperature and the snow-soil interface temperature by the handheld infrared thermometer simultaneous with the satellite in BG-A, BG-E, BG-F and BG-H. (2) Snow density, snow complex permittivity, snow volumetric moisture and snow gravimetric moisture by the Snowfork in BG-A, BG-E and BG-H. Besides, 25-hour fixed-point continuous observation was carried out at the Binggou cold region hydrometerological station. (3) The snow spectrum by ASD (Xinjiang Meteorological Administration) (4) Snow albedo by the total radiometer Two files including raw data and preprocessed data were archived.

2019-05-23

WATER: Dataset of airborne L-band microwave radiometer and thermal imager mission in the Binggou-A'rou flight zone in the afternoon of Apr. 1, 2008

The dataset of airborne L-band microwave radiometer and thermal imager mission was obtained in the Binggou-A'rou flight zone in the afternoon of Apr. 1, 2008. The frequency of L bands was 1.4 GHz with back sight of 35 degree and dual polarization (H&V) was acquired. The plane took off at Zhangye airport at 12:48 (BJT) and landed at 16:35 along the scheduled lines at the altitude about 5000m and speed about 260km/hr.. The raw data include microwave radiometer (L) data, thermal imager data (7.5-13 um; FOV: 24×18º) and GPS data; the first were instantaneous non-imaging observation recorded in text, which could be converted into brightness temperatures according to the caliberation coefficients (filed with raw data together), and the third are aircraft longitude, latitude and attitude. Moreover, based on the respective real-time clock log, observations by the microwave radiometer and GPS can be integrated to offer coordinates matching for the former. Yaw, flip, and pitch motions of aircraft were ignored due to the low resolution of microwave radiometer observations. Observation information can also be rasterized, as required, after calibration and coordinates matching. L band resolution (x) and footprint can be approximately estimated as x=0.3H (H is relative flight height). The thermal imager was 320*240 pixels and with FOV of 24×18º. The thermal imager data were stored in binary format with a text header file. The recorded value was brightness temperature at sensor with scale and gain parameter recorded in the header file. And the thermal images were not geometrically corrected because there were gaps between sequential images.

2019-05-23

WATER: Dataset of ground truth measurements for snow synchronizing with MODIS in the Binggou watershed foci experimental area on Mar. 19, 2008

The dataset of ground truth measurements for snow synchronizing with MODIS was obtained in the Binggou watershed foci experimental area on Mar. 19, 2008. Those provide reliable data for retrieval and verification of the snow temperature through airborne and satellite-borne remote sensing approaches. Observation items included: (1) Snow parameters, such as snow depth by the ruler (five measurements at random each point), the snow surface temperature by the infrared thermometer (several measurements at random), the snow layer temperature by the probe thermometer (10cm as an interval and two times each point), the snow grain size by the handheld microscope (10cm as an interval and three times each point) in BG-B from 12:40-13:00 (BJT) with the satellite overpass on Mar. 19, 2008. 64 points were selected by four groups. (2) Snow density, snow complex permittivity, snow volumetric moisture and snow gravimetric moisture by the Snowfork in BG-A,automatically in coordination with ASD. (3) The snow spectrum by the portable ASD. (4) Snow albedo by the portable radiometer in BG-A. Two files including raw data and preprocessed data were archived.

2019-05-23