Research On Hyperspectral Moving Target Detection Method In Complex Background Clutter

Real-time monitoring of civil aviation airplane is very important to protect the interests of countries and people,therefore,the International Civil Aviation Organization(ICAO)and the global industry are systematically promoting aircraft monitoring.At present,the main means of monitoring is to use radar and Automatic Dependent Surveillance-Broadcast(ADS-B)equipment of civil aviation airplane to transmit the status of civil aviation aircraft to the ground and satellite.The spaceborne ADS-B equipments are installed in the Iridium NEXT constellation,therefore,the global civil aviation airplane can be real-time monitored.However,global civil aviation airplane monitoring based on ADS-B system requires airplane to actively transmit flight status to satellite and the ground.When ADS-B equipment is damaged or subjected to interference,it is difficult for the ground to obtain the status of airplane.Radar can detect civil airplane when airplane does not actively transmit its status,however,the detection range of radar is limited.In order to explore an effective method to monitor the global airplanes,this paper studies airplane monitoring from the perspective of electro-optical target detection and it provides a reliable method to monitor airplane.The monitoring method based on spaceborne electro-optical target detection system has advantages of wide detection range,global coverage ability and do not need actively state transmission of airplane,and therefore,it is suitable for realtime monitoring of civil aviation airplane.The main contents and innovations of this paper are as follows:(1)The radiation transmission characteristics of civil aviation airplane and the earth background are systematically studied in this paper.The radiance of skin,plume,the earth in visible and near infrared bands,short-wave infrared bands,medium-wave infrared bands and long-wave infrared bands are studied.The effects of atmospheric attenuation on target and the earth background radiance are studied.The point target of civil aviation airplane and ground background clutter are modeled,and spaceborne electro-optical detection instrument system is modeled.(2)For the detection of civil airplane,the single-band single-frame detection method,single-band inter-frame difference detection method,hyperspectral detection method and multi-slit hyperspectral detection method are modeled and studied.The method of medium-wave multi-slit hyperspectral imaging detection can detect dim moving target with high spectral resolution,high spatial resolution and high temporal resolution and has the ability of all-day target detection and can detect the moving velocity of target.The detection performance of spaceborne medium-wave multi-slit hyperspectral imager is studied.The detection signal-to-clutter ratio of civil airplane is more than 20 when the spatial resolution is 150 m,the integration time is 0.005 s and the system F/#=2,and the detection signal-to-clutter ratio of plume spectrum is 15.The hyperspectral time-delay integration algorithm based on medium-wave multi-slit hyperspectral imager is studied.The results show that the hyperspectral time-delay integration algorithm can effectively improve spectral signal-to-clutter ratio.(3)Addressing high spectral resolution,high spatial resolution and high temporal resolution characteristics of multi-slit hyperspectral imager,a spectral difference anomaly target detection algorithm is proposed,which converts target detection from optical background domain to system noise domain and improves the detection performance of dim targets.The improved spectral detection algorithm is used to detect the residual image,which improves the overall stability of the algorithm.Theoretical research and experiments show that the proposed spectral difference anomaly target detection algorithm can effectively detect dim moving point targets in complex background clutter.The algorithm has stable detection performance and needs less computing resources.It is suitable for real-time target detection applications of spaceborne instruments.(4)Addressing the problem of target recognition,the target recognition algorithm based on spectral time-delay integration spectral angle matching is studied.The signal-toclutter ratio of the plume of civil aviation airplane is improved by using the spectral time-delay integration algorithm.The spectral angle matching algorithm can be used to identify the spectrum of the plume after unmixing.The influence of unmixing accuracy on spectral angular matching performance is studied.(5)A scheme of spaceborne medium-wave multi-slit hyperspectral imager detection system for real-time monitoring of civil airplane is proposed.The detection performance is studied and the orbital altitude is 500 km,the width is 1500 km,the time resolution is 15 min,the detection signal-to-clutter ratio is 20 of plume,and the number of satellites needed is 187.The experiment is done to verify the performance in 3.7-4.8?m.