The Design And Related Data Analysis Of Solar Spectral Radiometer From Visible To Near Infrared Bands

Based on the accurate tracking of solar or other target,the all-band solar spectral radiometer can measure continuous fine spectrum within the scope of the instrument.Total atmospheric transmittance and other radiation data can be obtained by the inversion and calculation of spectrum data.In order to develop a solar radiometer that can meet both our own research needs and future users,the data detection system,photoelectric imaging system,servo control system and mechanical transmission system are analyzed and studied in this article.In order to verify the reliability of the solar spectral radiometer,the measurement results of the instrument were compared with the results of the POM-2 radiometer and the calculation results of MODTRAN radiation transmission software.The research contents of this paper mainly include the following parts:(1)Based on the integrated design of data detection system,the structure and basic characteristics of the data detection system are analyzed.Considering the influence of grating multistage diffraction on the measurement data,we have taken corresponding improvement measures in terms of structure.(2)The photoelectric imaging system is introduced and the basic parameters of the imaging system are analyzed.The traditional four-quadrant tracking method can only be tracked accurately when the weather is clear and the solar radiation energy is evenly distributed in four quadrants,the method of image centroid extraction is proposed in this paper.The algorithm of centroid extraction is more applicable,it can still be used in the case of thin clouds around the sun.The image processing algorithm can be used to determine whether there is clouds or not,and then remove the cloud data from the total spectral data in a certain period of time to improve the accuracy of the calibration and measurement.(3)The whole working principle of the solar radiometer is introduced,and each module of the servo control system is analyzed.The structure style of the stable tracking device is introduced,and the two-axis single supporting structure is selected according to the actual working conditions.In this paper,two improved mechanical transmission structures are designed and introduced respectively.Finally,the improved synchronous belt deceleration structure is simulated based on RecurDyn.The experimental results show that the designed synchronous belt transmission structure is reasonable,it provides a scientific method and theoretical basis for the design of synchronous belt transmission system,and helps to study the mechanical transmission structure in the future.(4)According to the theory of multi-body dynamics and homogeneous coordinate transformation,coordinate system division and error modeling of single supporting solar radiometer are carried out.The main error and the error conversion matrix which affect the accuracy of the radiometer are calculated,and the theoretical basis is provided for the error distribution and compensation of the single supported solar radiometer.(5)Several typical calibration methods of solar radiometer are introduced,considering the merits and demerits of several methods,a hybrid calibration method is proposed to calibrate the solar radiometer.As a result,the calibrated datum is traced to the outside of the atmosphere,the error in the laboratory calibration process is been reduced.It provides a technical means for the measurement of atmospheric parameters in strong absorption band.(6)In order to reduce the influence of spectral noise on the measurement results,the wavelet transform is used for baseline correction and spectral de-noising simultaneously.The experiment shows that the wavelet de-noising method can replace the dark noise method used in the traditional solar radiometer,and reduces the complexity of the design of the instrument.Finally,the compared experiment was carried out between the full band solar spectral radiometer and the POM-2,the measurement results are compared with those calculated by MODTRAN,it showed the reliability of the instrument design and proved the accuracy of calibration methods.