The purpose of differential GPS positioning survey is to unify multiple survey areas into the same coordinate system and realize accurate absolute positioning through joint survey with national high-level control point coordinates. Under the national geodetic coordinate system of 2000, the accurate positioning of flux observation matrix, hulugou small watershed, tianmuchi small watershed and dayokou watershed and target is completed. In order to realize the geometric correction and absolute positioning of optical image, SAR image and airborne lidar data, the layout of ground control points and high-precision measurement are completed. In the middle reaches of the area, one national high-level control point is jointly surveyed in the five directions of East, South, West, North and middle. Measuring instrument: There are 3 sets of triple R8 GNSS system. Measurement principle: For the control network encryption point, it is connected with the high-level known points in four quadrants around the survey area and distributed evenly in the survey area. For the ground control point (GCP), the obvious characteristic points (such as house corner, road intersection, inflection point, etc.) of the ground layout target and the independent ground objects are adopted and evenly distributed in the survey area. For the ground points with high accuracy requirements, the principle of average value of multiple (at least three) measurements is adopted. Measurement method: In the test area, the control network is encrypted, and GPS static measurement and national high-level control network are used for joint measurement and calculation. During measurement, multiple GPS receivers conduct static synchronous observation at different stations, and the observation time is strictly in accordance with the control network measurement specifications. The ground points in the test area are accurately located. GPS-RTK positioning technology is used and the national high-level control points are used to calibrate to the local coordinate system. When the mobile station obtains the fixed solution during the coordinate acquisition, the measurement is carried out again and the single measurement lasts for 5S. Measuring position: (1) Flux observation matrix 17 stations, Las tower, waternet, soilnet and bnunet nodes in the core area of flux observation matrix; ground control points in CASI flight area; ground corner reflector positions in radar coverage area; ground target positions in lidar flight area. (2) Hulugou small watershed Ground target location of lidar flight area. (3) Tianmuchi small watershed Ground target location of lidar flight area. (4) Dayokou Basin Satellite image geometric correction ground control point. Data format: GPS static survey, the original data format is ". Dat" and ". T01" (or ". T02") files (or converted renix data) and "field record". GPS-RTK survey, the original project is ". Job" file (or converted ". DC" file). The test results are submitted in the format of exported ". CSV" data, which can be viewed and edited by Excel software. Measurement time: June 19, 2012 to July 30, 2012
2020-03-13
This data set includes the continuous observation data set of light temperature and surface temperature and humidity measured by the vehicle borne microwave radiometer from November 10 to 14, 2013 in aroucaochang, arouxiang, Qilian County, Qinghai Province. The surface temperature and humidity include six layers of temperature sensor at the soil depth of 1cm, 3cm, 5cm, 10cm, 15cm, 20cm and six layers of humidity sensor at the soil depth of 0-5cm. The time frequency of routine observation of soil temperature and humidity is 5 minutes. Data details: 1. Time: November 10-14, 2013 2. data: Brightness temperature: observed by vehicle mounted multi frequency passive microwave radiometer, including 6.925, 10.65, 18.7 and 36.5ghz V polarization and H polarization data Soil temperature: use the sensor installed on dt80 and dt85 to measure the soil temperature of 1cm, 5cm, 10cm, 20cm, and 1cm, 3cm, 5cm, 10cm, 15cm, which is measured by the sensor connected to dt80 Soil moisture: use h-probe sensor to measure 0-5cm soil moisture, the probe can measure 0-5cm soil temperature at the same time 3. Data size: 16.7M 4. Data format:. Xls
2020-03-13
This data set was acquired by K & Ka band airborne microwave radiometer on March 29, 2008, in the Binggou watershed flight zone. Among them, K-band frequency is 18.7ghz, zenith angle observation, no polarization information; Ka band frequency is 36.0ghz, scanning imaging, scanning range ± 12 °, vertical polarization observation. The plane took off from Zhangye airport at 8:49 (Beijing time, the same below) and landed at 12:54. 9: At 25-12:08, 18 routes were flown according to the scheduled design, with a flight altitude of about 5000m and a flight speed of about 220-250km / hr. The original data is divided into two parts: microwave radiometer data and GPS data. The K-band of microwave radiometer belongs to non imaging observation, and the digital value obtained from instantaneous observation is recorded in the text file. Ka band belongs to imaging observation, which is different from L band and K band data. The original record of Ka band is hexadecimal text file. In data processing, the hexadecimal file needs to be converted to decimal system first, and then 112 data (the angle difference of each two data points is 24 / 112 = 0.214 degrees) are collected uniformly within the scanning range of 24 degrees. GPS data record the latitude and longitude of the flight and the aircraft attitude parameters. When using microwave radiometer to observe data, it is necessary to convert the digital value recorded into the bright temperature value according to the calibration coefficient (the calibration coefficient file is filed with the original observation data). At the same time, through the clock records of microwave radiometer and GPS, microwave observation and GPS record can be linked to match the geographical coordinate information for microwave observation. When processing Ka band data, the angle scanning effect should also be considered, and 112 data in the scanning period should be given geographical coordinate information respectively. Due to the coarse observation resolution of microwave radiometer, the effects of aircraft yaw, roll and pitch are generally ignored in data processing. According to the target and flight relative altitude (H), after calibration and coordinate matching, the observation information can also be gridded. The resolution (x) of K-band is consistent with that of observation footprint. The reference resolution is: x = 0.24h; the resolution of Ka band is 39m. After the above steps, we can get the products that users can use directly.
2020-03-09
This data set was acquired by the L & K band airborne microwave radiometer on the morning of April 1, 2008, in the A'rou flight zone. The frequency of L-band is 1.4GHz, and the backsight is 35 degrees to obtain dual polarization (H and V) information; the frequency of K-band is 18.7ghz, and there is no polarization information. The plane took off from Zhangye airport at 8:06 (Beijing time, the same below) and landed at 11:17. 8: 50-10:13 fly from north to south, observe and reserve 10 routes, flight height is about 4100m, flight speed is about 260km / hr. 10: At 20-10:35, Jiafei 6-8 and 6-9 lines completed the observation. The original data is divided into two parts: microwave radiometer data and GPS data. The L and K bands of microwave radiometer are non imaging observations. The digital values obtained from the instantaneous observation are recorded in the text file, and the longitude and latitude as well as the aircraft attitude parameters are recorded in the GPS data. When using microwave radiometer to observe data, it is necessary to convert the digital value recorded into the bright temperature value according to the calibration coefficient (the calibration coefficient file is filed with the original observation data). At the same time, through the clock records of microwave radiometer and GPS, we can connect the microwave observation with GPS record and match the geographic coordinate information for the microwave observation. Due to the coarse observation resolution of microwave radiometer, the effects of aircraft yaw, roll and pitch are generally ignored in data processing. According to the target and flight relative altitude (H), after calibration and coordinate matching, the observation information can also be gridded. The resolution (x) of L band and K band is consistent with that of observation footprint. The reference resolution is: L band, x = 0.3H; K band, x = 0.24h. After the above steps, we can get the products that users can use directly.
2020-03-09
The medium resolution imaging spectrometer (MERIS) is a sensor mounted on the ENVISAT satellite of the European Space Agency. It has 15 spectral segments and scans the earth's surface by push sweep method. The incident angle of the point below the star is 68.5 degrees and the width is 1150km. At present, there are 56 ENVISAT MERIS data in Heihe River Basin. Acquisition time: 2008-05-01, 2008-05-02, 2008-05-03, 2008-05-05, 2008-05-07, 2008-05-08, 2008-05-11, 2008-05-14, 2008-05-17 (2 scenes), 2008-05-20 (2 scenes), 2008-05-21 (2 scenes), 2008-05-23 (2 scenes), 2008-05-24, 2008-05-30, 2008-05-31, 2008-06-01, 2008-06-02, 2008-06-05, 2008-06-06, 2008-06-09, 2008-06-12, 2008-06-15, 2008-06-18, 2008-06-21, 2008-06-22, 2008-06-24 (2 scenes), 2008-06-25, 2008-06-27, 2008-06-30, 2008-07-01, 2008-07-02, 2008-07-04, 2008-07-07, 2008-07-10, 2008-07-11, 2008-07-13 (2 scenes), 2008-07-13, 2008-07-16, 2008-07-17, 2008-07-20, 2008-07-23 (2 scenes), 2008-07-26 (2 scenes), 2008-07-27, 2008-07-29, 2008-07-30, 2008-08-01, 2008-08-02. The product level is L1B without geometric correction. The ENVISAT MERIS remote sensing data set of Heihe integrated remote sensing joint experiment was obtained through the China EU "dragon plan" project (Project No.: 5322) (see the data use statement for details).
2020-03-09
In 2007, 2008 and 2009, ENVISAT ASAR data 179 scenes, covering the whole Heihe River Basin. Among them, there were 63 in 2007, 71 in 2008 and 45 in 2009. Imaging mode and acquisition time are respectively: app can select polarization mode from August 15, 2007 to December 23, 2007, from January 02, 2008 to December 202009-02-15, 2008 to September 06, 2009; imp imaging mode from June 19, 2009 to July 12, 2009; WSM wide mode from January 1, 2007 to December 302008-01-01, 2007 to November 28, 2008, from March 13, 2009 to May 22, 2009. The product level is L1B, which is amplitude data without geometric correction. The ENVISAT ASAR remote sensing data set of Heihe comprehensive remote sensing joint experiment is mainly obtained through the China EU "dragon plan" project (Project No.: 5322 and 5344); the WSM wide model data in 2007 and January 2008 are obtained from Professor Bob Su of ITC; the 8-view app can be purchased from the earth observation and digital earth center of Chinese Academy of Sciences.
2020-03-09
Advanced along orbit scanning radiometer (AATSR) is an advanced tracking scanning radiometer sensor mounted on the European Space Agency ENVISAT satellite. It is one of many high-precision and stable infrared radiometers for retrieving sea surface temperature (SST). Its accuracy can reach 0.3k, and it can also be used to record meteorological data. AATSR is a multi-channel imaging radiometer. Its main goal is to provide global ocean surface temperature with high accuracy and stability for monitoring the earth's climate change. At present, there are 38 ENVISAT AATSR images in Heihe River Basin. The acquisition time is 2008-05-17 (2 scenes), 2008-05-27 (2 scenes), 2008-05-30 (2 scenes), 2008-06-02 (2 scenes), 2008-06-12 (2 scenes), 2008-06-15 (2 scenes), 2008-06-18 (2 scenes), 2008-06-21 (2 scenes), 2008-07-04 (2 scenes), 2008-07-072008-07-102008-07-172008-07-202008-07-232008-07-262008-08-022008-08-052008-08-082008 -08-11，2008-08-14，2008-08-21，2008-08-24，2008-08-27，2008-08-30，2008-09-06，2008-09-12，2008-09-15，2008-09-18，2008-09-25。 The product level is L1B, which has been corrected by radiation but not by geometry. The ENVISAT AATSR remote sensing data set of Heihe comprehensive remote sensing joint test was obtained through the China EU "dragon plan" project (Project No.: 5322) (see the data use statement for details).
2020-03-09
ASTER data in 2007 and 2008 are 15 scenes, covering the whole Heihe River Basin. Acquisition time: 2007-10-22 (1 scene), 2007-11-14 (1 scene), 2007-11-23 (1 scene), 2007-12-04 (1 scene), 2008-01-28 (1 scene), 2008-02-13 (1 scene), 2008-05-03 (4 scenes), 2008-05-05 (1 scene), 2008-05-17 (1 scene), 2008-06-04 (2 scenes), 2008-06-13 (1 scene). The product level is L1B, which has been calibrated by radiation and geometry. The ASTER Remote sensing data set of Heihe integrated remote sensing joint experiment was obtained from NASA's data website (https://wist.echo.nasa.gov/) through international cooperation.
2020-03-09
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)
2020-03-09
The data set contains the flux observation data of large aperture scintillator at areau station upstream of heihe hydrometeorological observation network.Two large aperture scintillation devices of BLS450 and zzlas type were set up in the upstream areau station respectively. The north tower was the receiving end of zzlas and the transmitting end of BLS450, and the south tower was the transmitting end of zzlas and the receiving end of BLS450.The observation time is January 1, 2017, solstice, December 31, 2017.The station is located in the grass daban village, a soft township, qilian county, qinghai province.The latitude and longitude of the north tower is 100.4712e, 38.0568n, and the latitude and longitude of the south tower is 100.4572e, 38.0384 N, with an altitude of about 3033m.The effective height of the large aperture scintillator is 9.5m, the optical diameter length is 2390m, and the sampling frequency is 1min. Large aperture flicker meter raw observation data for 1 min, data released for after processing and quality control of data, including sensible heat flux is mainly combined with the automatic meteorological station observation data, based on similarity theory alonzo mourning - Mr. Hoff is obtained by iterative calculation, the quality control of the main steps include: (1) excluding Cn2 reach saturation data (BLS450: Cn2 > 7.25 e-14, zzlas: Cn2 > 7.84 E - 14).(2) data with weak demodulation signal strength (BLS450: Mininum X Intensity <50) were eliminated;Zzlas: Demod>-20mv);(3) data at the time of precipitation were excluded;(4) data of weak turbulence under stable conditions were excluded (u* < 0.1m/s).In the iterative calculation process, for BLS450, Thiermann and Grassl(1992) stability universal function was selected.For zzlas, select Andreas 1988's stability universal function.Please refer to Liu et al(2011, 2013) for detailed introduction.From April 16 to May 26, 2017, the measurement signal of large aperture scintillator was relatively small, resulting in a large number of missing data. Several notes on the released data :(1) the upstream LAS data is mainly BLS450, the missing time is supplemented by zzlas observation, and the missing time of both is marked by -6999.(2) data table head: Date/Time: Date/Time (format: yyyy/m/d h:mm), Cn2: structural parameters of air refraction index (unit: m-2/3), H_LAS: sensible heat flux (unit: W/m2).The meaning of data time, such as 0:30 represents the average between 0:00 and 0:30;The data is stored in *.xls format, please refer to the references for details. Please refer to Li et al. (2013) for hydrometeorological network or site information, and Liu et al. (2011) for observation data processing.
2020-03-05
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