Research On Anctive And Passive Detection System For UAV-borne Seawater Oil Pollution

Because of the extremely uneven distribution of oil and the increasing global demand for oil,a large amount of oil has been exploited and transported to all parts of the world by sea.In this process,serious marine oil spill pollution is often accompanied,which is harmful to the marine environment.In the treatment of marine oil spill pollution,it is necessary to have a sufficient understanding of the distribution information of oil pollution in the polluted areas.In marine oil spill detection,multi-spectral oil spill remote sensing detection can distinguish true and false targets with a large detection range,but it can not achieve accurate measurement of oil film thickness,and can only work under sufficient sunshine conditions.Laser-induced fluorescence oil spill detection can achieve accurate measurement of oil film thickness,but its detection range is small and can only work at night.Therefore,the combination of the two detection methods can achieve all-weather offshore oil spill detection.Based on these two remote sensing methods,an active and passive marine oil pollution detection system for UAV is introduced in this thesis.The main research contents are as follows:Firstly,the principle of multi-spectral remote sensing,the classification method of multi-spectral images and the evaluation method are studied,and the principle of measuring oil film thickness by laser-induced fluorescence is analyzed.Based on the principle of multi-spectral remote sensing oil spill detection,a passive oil spill detection system for UAV was designed and built,and an active oil spill detection system for UAV was designed based on laser induced fluorescence detection.Secondly,the passive oil pollution detection system of UAV is used to carry out experiments.The maximum likelihood method,the minimum distance method and the spectral angle mapping method are used to classify the multi-spectral images respectively.The oil spill distribution information of the target area is obtained and the accuracy of the classification results of the three methods is evaluated.In addition,the oil spill area can be displayed in a relatively large range by image mosaic.Experiments show that the passive oil pollution detection system on UAV can detect oil pollution in a relatively large area under sufficient sunshine conditions,and obtain the roughly distribution of oil pollution in the target area.Finally,the experiment was carried out with the UAV-based active oil pollution detection system.The fluorescence spectrum characteristics of different oil pollution and the fluorescence intensity of different oil film thickness were obtained.The oil film thickness and the fluorescence to Raman ratio were fitted by the improved fluorescence to Raman ratio method and the error analysis was carried out.Experiments show that the active oil pollution detection system on UAV can detect the type and thickness of oil pollution accurately at night.Through the cooperation of the two systems,all-weather,wild-area,high-precision pollution oil detection can be realized.