Research On Calibration System Of Photoelectric Sunshine Duration Recorder

The sunshine duration measured by a sunshine duration recorder is one of the main methods for studying aerography and climatology.With the development of photoelectric technology,the photoelectric sunshine duration recorder has become a research focus of the instrument which is using for observing the sunshine duration.However,the existing calibration method for photoelectric sunshine duration recorder(comparative measurement in the open air)often takes much longer time to complete due to the weather effect.Moreover,the accuracy of the calibration results is low and difficult to reproduce,thus the backwardness of the calibration method has severely restricted the development of photoelectric sunshine duration recorder.In order to improve the calibration accuracy and efficiency of photoelectric sunshine duration recorder,this paper has carried out researching on the calibration technology of it.The calibration system of photoelectric sunshine duration recorder has been designed,focusing on the solar direct radiation simulation method and the calibration method of calibration system.The calibration system designed in this paper can be used not only for performance testing and precision calibration of the existing photoelectric sunshine duration recorders,but also for other new type photoelectric sunshine duration recorders in the future.This paper explains the theory related solar radiation,including the solar,solar radiation and its intensity,atmospheric quality,solar constant,solar position angle and solar spectrum;it researches the basic structure,operating principle and calibration method of photoelectric sunshine duration recorder;and combined with direct radiation simulation technology,scattering radiation simulation technology and solar-terrestrial relationship regulating technology,the implement methods and main technical indicators of each components of the calibration system are determined,and the overall design of the calibration system for photoelectric sunshine duration recorder is completed.For technical indicators of direct radiation simulation system,combining with relevant design technologies such as radiation source,optical path steering device,spot shaping and beam equalizing system,and collimation optical system,etc.to complete the overall design for direct radiation simulation optical system;studying a method of energy distribution modulation of radiation source to improve the energy efficiency of the optical system;a spectral correction model is established to calculate the corresponding transmittance of the spectrally modified different bands;the optical axis adjustment method of direct radiation simulation system is proposed,and the error compensation structure is designed,the problemof optical axis consistency in optical systems is solved,and the direct radiation simulation system adjustment is completed.The calibration methods of the direct radiation simulation system,the scattering radiation simulation system and the solar-terrestrial regulation system are studied,and the calibration chain of the photoelectric sunshine duration recorder calibration system is established to ensure the traceability of the system calibration results.And the performance of the direct radiation simulation system,the scattering radiation simulation system,the solar-terrestrial regulation system,and photoelectric sunshine recorder calibration system is verified through a series of experiments.The experimental results show that the simulation error of sunshine duration in photoelectric sunshine duration recorder calibration system within 480 minutes is 3.75%,which satisfies the calibration requirements of photoelectric sunshine duration recorder.In conclusion,the calibration system of photoelectric sunshine duration recorder studied in this paper can be used for photoelectric sunshine duration recorder performance testing and accuracy calibration.It solve the process which is cumbersome of the existing photoelectric sunshine recorder calibration,relying heavily on meteorological environment and time-consuming issues,achieve the photoelectric sunshine recorder's high-precision,high-efficiency for calibration indoor.It has important practical significance for the promotion of photoelectric sunshine recorder and the establishment of an automatic observation network for sunshine duration.