Opto-mechanical Design Of All-Weather Infrared Cloud Measuring Device

With the rapid development of cloud measuring technology,the cloud measuring system in the visible band is gradually replaced by the cloud measuring system in the infrared band,the infrared cloud measuring device is becoming a research hotspot in the field of meteorology.The infrared cloud measuring system is less affected by the environment,and it can be used to obtain the infrared radiation information of cloud under the condition of the low visibility or the weak light transmittance,thus the distribution information of cloud is obtained in real time,which achieves cloud observation under all-weather conditions.The cloud measuring device works in a complex environment,so it is necessary to reduce the volume of the optical system and the structure frame to carry out integrative design of optical systems and mechanical structures.Therefore,the comprehensive study of the all-weather infrared measuring system is carried out in this paper.In order to realize the wide-range detection for the cloud,an opto-mechanical system using infrared panoramic imaging optical system for realizing observation cloud under all-weather conditions is designed in this paper.Firstly,according to the linear relationship between angles,the formula of the small distortion reflector type is derived.On this basis,a catadioptric infrared panoramic optical system is designed.The optical system completes the athermal design by means of the combination of diffracted plane and aspheric surface,the detection distance of optical system is estimated,the sensitivity analysis method and monte carlo analysis method are used to analyze the tolerance of the system.Secondly,the opto-mechanical structure of the cloud device is designed,it includes the design of lens group structure;the design of a double slit flexible structure for the diaphragm;the design of the lightweight reflector structure;and the support structure between the refraction unit and the reflector adopts symmetrical three-wing structure.Finally,the modal analysis and temperature adaptability analysis of the opto-mechanical system are carried out with the finite element method,then its natural frequencies and vibration modes are obtained,and the surface deformation and stress of each optical element under uniform temperature loading are obtained.In this paper,the working band of the opto-mechanical system of the infrared measuring cloud device is 8?12?m,and the detection distance is 7km.Just shooting once,the scene information of the filed of view is 360°×120° can be obtained,the imaging quality is good in all field of view.The system base frequency is greater than 20Hz,and it is not easy to resonate in the external environment.Under the action of temperature loading,the surface deformation is within the tolerance requirement(0.02mm)of the device,and the stress produced is less than the limit strength of each material.The structure of the whole opto-mechanical system is simple and the image quality is stable,the design meets the index requirement.