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
Central RF frequency is a key parameter of storage rings. This paper presents the measurement of central RF frequency of the HLS-Ⅱ storage ring with the sextupole modulation method. Firstly, the basis of central RF f...Central RF frequency is a key parameter of storage rings. This paper presents the measurement of central RF frequency of the HLS-Ⅱ storage ring with the sextupole modulation method. Firstly, the basis of central RF frequency measurement of the electron storage ring is briefly introduced. Then, the error sources and the optimized measurement method for the HLS-Ⅱ storage ring are discussed. The workflow of a self-compiled Matlab script used in central RF frequency measurement is also described. Finally, the results achieved by using two data processing methods to cross-check each other are shown. The measured value of the central RF frequency demonstrates that the circumference deviation of the HLS-Ⅱ storage ring is less than 1 mm.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 National Natural Science Foundation of China(11105141,11175173)the upgrade project of Hefei Light Source
文摘Central RF frequency is a key parameter of storage rings. This paper presents the measurement of central RF frequency of the HLS-Ⅱ storage ring with the sextupole modulation method. Firstly, the basis of central RF frequency measurement of the electron storage ring is briefly introduced. Then, the error sources and the optimized measurement method for the HLS-Ⅱ storage ring are discussed. The workflow of a self-compiled Matlab script used in central RF frequency measurement is also described. Finally, the results achieved by using two data processing methods to cross-check each other are shown. The measured value of the central RF frequency demonstrates that the circumference deviation of the HLS-Ⅱ storage ring is less than 1 mm.
