The spectral radiation characteristic of a non-luminous flame is analyzed. The apparatus and the calibration procedure based on infrared emission spectrometry for measurements of the flame are introduced. The influenc...The spectral radiation characteristic of a non-luminous flame is analyzed. The apparatus and the calibration procedure based on infrared emission spectrometry for measurements of the flame are introduced. The influence of background radiation and stray light on the measurement results could be reduced and suppressed by the design of thermolator and digital lock-in technique. A blackbody cavity was used as reference emission source to calibrate the system that completed absolute measurement. The spectral mea- surement range is 1-20μm. The least measuring distance and the lowest power detected at the entrance pupil are 550 mm and 10^-9 W/cm^2, respectively. The experimental results show that the measure error is less than 10%.展开更多
Based on the analysis for the main elements of the total modulation transfer function （MTF） of imager on geostationary platform, the precise evaluation for its low spatial frequency spectrum has been achieved. Meanw...Based on the analysis for the main elements of the total modulation transfer function （MTF） of imager on geostationary platform, the precise evaluation for its low spatial frequency spectrum has been achieved. Meanwhile, it is pointed out that the main cause of imagery spatial resolution lower than the designed value is the ＂slight defocus＂ of imager focal plane array （FPA）. The validation method for visible imagery spatial resolution is proposed based on the analysis of defocused optical system model and edge-spread-function （ESF）, the relative error is less than 7% after alleviating stray light effects. This method has been applied in the in-orbit ground testing of FY-2C geostationary meteorological satellite successfully.展开更多
文摘The spectral radiation characteristic of a non-luminous flame is analyzed. The apparatus and the calibration procedure based on infrared emission spectrometry for measurements of the flame are introduced. The influence of background radiation and stray light on the measurement results could be reduced and suppressed by the design of thermolator and digital lock-in technique. A blackbody cavity was used as reference emission source to calibrate the system that completed absolute measurement. The spectral mea- surement range is 1-20μm. The least measuring distance and the lowest power detected at the entrance pupil are 550 mm and 10^-9 W/cm^2, respectively. The experimental results show that the measure error is less than 10%.
基金This work was supported by the National Natural Science Foundation of China under Grant No. 40401040.
文摘Based on the analysis for the main elements of the total modulation transfer function （MTF） of imager on geostationary platform, the precise evaluation for its low spatial frequency spectrum has been achieved. Meanwhile, it is pointed out that the main cause of imagery spatial resolution lower than the designed value is the ＂slight defocus＂ of imager focal plane array （FPA）. The validation method for visible imagery spatial resolution is proposed based on the analysis of defocused optical system model and edge-spread-function （ESF）, the relative error is less than 7% after alleviating stray light effects. This method has been applied in the in-orbit ground testing of FY-2C geostationary meteorological satellite successfully.
