Widas (wide angle infrared dual-mode line / area array) was obtained by CE318 solar spectrophotometer in Yingke oasis and huazhaizi desert intensive observation area Scanner, omis-2, TM, aster, Chris and Hyperion, as well as conventional observation of atmospheric parameters provide important atmospheric parameters for atmospheric correction of various remote sensing images and ground measurement data. The original data is stored in CE318 special file format. K7 and can be opened by astpwin software. The preprocessing file includes the retrieval of optical thickness, Rayleigh scattering, aerosol optical thickness, horizontal visibility and near surface atmospheric temperature from the original data, as well as the solar azimuth, zenith angle, sun earth distance correction factor and atmospheric column mass involved in the calculation. Data preprocessing result file includes two parts: data processing description and data processing result. The former introduces the basic principle of data processing, while the latter gives the results of data processing, including "geometric position and total optical thickness of each channel" and "Rayleigh scattering and aerosol optical thickness of each channel".
The infrared temperature data are calibrated; In the original record, the number of infrared thermometer in sample a area is Feng Lei -#3, which lacks the corresponding calibration coefficient, so the infrared temperature calibration cannot be carried out; There is no data record for flight belt 10 in sample area B; The end time is not recorded in line7 of flight belt 8 data and line5 of 120m quadrat data in sample area C.
CE318 solar spectrophotometer can inverse the optical thickness, Rayleigh scattering and aerosol optical thickness of non water vapor channel through the direct solar radiation measurement data. The water vapor content of atmospheric gas column can be obtained from the 936nm measurement data of water vapor channel. According to the needs, the data can obtain various parameters at 550nm, so as to obtain horizontal visibility with the help of software such as MODTRAN or 6S
Test instrument: one CE318 of Beijing Normal University and one CE318 of Institute of remote sensing of Chinese Academy of sciences are adopted. Among them, CE318 of Beijing Normal University can provide the optical thickness of five bands: 1020nm, 936nm, 870nm, 670nm and 440nm, and the water vapor content of atmospheric column can be retrieved by using 936nm measurement data; CE318, Institute of remote sensing, Chinese Academy of Sciences, can provide the optical thickness of 9 bands: 1640nm, 1020nm, 936nm, 870nm, 670nm, 550nm, 440nm, 380nm and 340nm, and can retrieve the water vapor content of the atmospheric column using 936nm measurement data
Measurement time: the two instruments carried out 24 observations in 15 days in Yingke oasis and huazhaizi desert intensive observation area and Zhangye intensive observation area, respectively: 2008-05-202008-05-232008-05-252008-05-272008-06-042008-06-062008-06-162008-06-202008-06-222008-06-232008-06-272008-06-292008-07-01, 2008-07-072008-07-11, It was synchronized with the wide-angle infrared dual-mode line / area array scanner (widas), imaging spectrometer omis-2, TM, aster, Chris, Hyperion and other satellites.
Factors affecting CE318 data accuracy: local atmospheric pressure, instrument calibration parameters and various conversion factors
（ 1) During the calculation of preprocessed data, the atmospheric pressure is obtained by using the empirical relationship between atmospheric pressure and elevation, which is mostly inconsistent with the reality. Therefore, in order to obtain accurate inversion results, synchronous meteorological station data is required;
（ 2) The error of instrument calibration data causes the systematic error of inversion results, so it is necessary to organize field calibration or instrument indoor calibration;
（ 3) The inversion of aerosol optical thickness and water vapor content in water vapor channel requires various conversion factors. The conversion factors are empirical parameters, and their practicability needs to be further verified. Outdoor calibration: under the condition of stable atmospheric parameters, obtain the measurement data with atmospheric mass number between 3-7, and calibrate with langly principle; Indoor calibration: standard light source.
& emsp; Factors affecting CE318 data accuracy: local atmospheric pressure, instrument calibration parameters and various conversion factors.（ 1) During the calculation of preprocessed data, the atmospheric pressure is obtained by using the empirical relationship between atmospheric pressure and elevation, which is mostly inconsistent with the reality. Therefore, in order to obtain accurate inversion results, synchronous meteorological station data is required;
（ 2) The error of instrument calibration data causes the systematic error of inversion results, so it is necessary to organize field calibration or instrument indoor calibration;
（ 3) The inversion of aerosol optical thickness and water vapor content in water vapor channel requires various conversion factors. The conversion factors are empirical parameters, and their practicability needs to be further verified. Outdoor calibration: under the condition of stable atmospheric parameters, obtain the measurement data with atmospheric mass number between 3-7, and calibrate with langly principle; Indoor calibration: standard light source.
Good data quality
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CC BY 4.0 (Creative Commons Attribution 4.0 International License).
CSTR:11738.11.ncdc.NIEER.2021.1807
10.12072/ncdc.NIEER.db1787.2022
