We employ the in-site automated observation radiometric calibration（AORC） approach to perform vicarious calibration, which does not require the manual efforts of a field team to measure the surface conditions. By us...We employ the in-site automated observation radiometric calibration（AORC） approach to perform vicarious calibration, which does not require the manual efforts of a field team to measure the surface conditions. By using an automated test-site radiometer（ATR）, the surface radiance at any moment in time can be obtained. This Letter describes the AORC approach and makes use of data to compute top-of-atmosphere radiance and compare it to measurements from the Moderate Resolution Imaging Spectroradiometer. The result shows that the relative deviation is less than 5% and the uncertainty is less than 6.2%, which indicates that the in-site AORC maintains an accuracy level on par with traditional calibration.展开更多
Ultraviolet(UV) absorption spectroscopy is used to detect the concentration of water chemical oxygen demand(COD). The UV absorption spectra of COD solutions are analyzed qualitatively and quantitatively. The partial l...Ultraviolet(UV) absorption spectroscopy is used to detect the concentration of water chemical oxygen demand(COD). The UV absorption spectra of COD solutions are analyzed qualitatively and quantitatively. The partial least square(PLS) algorithm is used to model COD solution and the modeling results are compared. The influence of environmental temperature and turbidity is analyzed. These results show that the influence of temperature on the predicted value can be ignored. However, the change of turbidity can affect the detection results of UV spectra, and the COD detection error can be effectively compensated by establishing the single-element regression model.展开更多
基金supported by the National “863” Program of China(No.2015AA123702)the National Natural Science Foundation of China(Nos.11204318 and61275173)
文摘We employ the in-site automated observation radiometric calibration（AORC） approach to perform vicarious calibration, which does not require the manual efforts of a field team to measure the surface conditions. By using an automated test-site radiometer（ATR）, the surface radiance at any moment in time can be obtained. This Letter describes the AORC approach and makes use of data to compute top-of-atmosphere radiance and compare it to measurements from the Moderate Resolution Imaging Spectroradiometer. The result shows that the relative deviation is less than 5% and the uncertainty is less than 6.2%, which indicates that the in-site AORC maintains an accuracy level on par with traditional calibration.
基金supported by the National Natural Science Foundation of China(No.61475133)the Science and Technology Research and Development Project of Hebei Province(Nos.14273301D,15273304D,16273301D and 16213902D)
文摘Ultraviolet(UV) absorption spectroscopy is used to detect the concentration of water chemical oxygen demand(COD). The UV absorption spectra of COD solutions are analyzed qualitatively and quantitatively. The partial least square(PLS) algorithm is used to model COD solution and the modeling results are compared. The influence of environmental temperature and turbidity is analyzed. These results show that the influence of temperature on the predicted value can be ignored. However, the change of turbidity can affect the detection results of UV spectra, and the COD detection error can be effectively compensated by establishing the single-element regression model.
