Research On Infrared Imaging And Detection Technology Of Near-space Platform

Near space is the region that located between 20 km to 100 km altitude above Earth’s mean sea level,which has great value in development and application,and is an important part of the “Tian-Lin-Kong-Di” integrated system.Stratospheric airship is a new type of near-space vehicle with a stable atmospheric environment at flying altitude,capable of staying airborne for a long time,performing high-altitude patrols,scientific investigations,and communication relay tasks.The observation load carried on the airship platform has unique advantages in high-resolution real-time observation tasks,and is a powerful supplement to aviation and aerospace observations.At present,the near space platform and related mission load system are in the stage of development and verification.In order to explore the near-space infrared optical payload technology and promote the application of near-space technology in the field of observation,this paper relies on the near-space infrared observation project to design and implement an infrared optical payload system that can be carried on a stratospheric airship,and has achieved practical results.First of all,this paper analyzes the working environment and mission requirements of the infrared optical detection load in the near space,and proposes the overall scheme of the short-wave and long-wave dual-band infrared detectors,and determines the functional requirements and key indicators of the system.Then,according to the platform resources and limitations,the composition framework and basic working mode of the system are further designed.Secondly,starting from the overall framework of the system,on the basis of fully considering the system hardware requirements and software design,the system hardware composition scheme was proposed,the system hardware workflow was designed,and the hardware realization including infrared optical system and detector scheme,load electronics scheme,load structure scheme was completed.Thirdly,according to the overall system framework and hardware design,the system software scheme was proposed,the functional requirements of each component of the software were clarified,and development tools were selected,software architecture and workflow were designed.The system software was then developed,and a series of the system functional requirements were realized,including payload remote control,real-time display of task images,target automatic detection and positioning and so on.Then,aiming at the target detection algorithm in the detection system,a spatio-temporal network based on YOLOv3 and a traditional method based on local contrast features are proposed.The two methods are organically combined to achieve real-time detection of small and dim targets in infrared image sequences.And a real data set was built,which joined the public data set to test the proposed algorithm in comparative experiments.The result shows that the algorithm in this paper is better than the baseline algorithms.Finally,The functional tests and environmental tests of the complete system verified that the system can meet the functional requirements in the preset environment;then the system was mounted on the platform,participated in the flight experiment,and obtained a lot of important data,which provided a reference for the further study of infrared detection payload in near space.