Research Of Data Preprocess Key Technology On Area-array Detector Adopting Whiskbroom Scaning Mode

UAV remote sensing is a new monitoring technology.Because of its low cost,high efficiency and convenience,it can fly in low altitude under cloud,UAV remote sensing has been widely used in various fields.In the UAV imaging system,compared with the linear array,the image acquired by the area array has a relatively stable internal geometric relationship,and the area array swing scanning imaging mode has its unique advantages in the fields of aviation military reconnaissance,emergency relief and tilt photogrammetry due to its advantages of large total field angle,wide observation range,instant gaze imaging,etc In order to pay attention to a new type of remote sensing load,at this stage,the research on the key problems of this kind of data preprocessing is relatively less,and the research on the application problems caused by the data obtained by this imaging method is not deep enough.In this thesis,the plane array swing scan aviation image data is taken as the research object,and the problems encountered on the plane array swing scan aviation image preprocessing are studied in depth.It is hoped that the research of this paper can provide some reference for the whole process of geometric correction,splicing and application of plane array swing scan aviation image data.The main contents and innovations of this paper are as follows:(1)A fast geometric correction method based the virtual camera is proposed.The spatial resolution of the single image is different.If the geometric correction is not carried out,the resolution of the image directly spliced will be in the shape of a ridge,and the massive image correction is very time-consuming.It is found that the curvature of the earth has little effect on the result of UAV image correction,so a geometric correction method based the virtual camera is proposed.On the premise of ensuring the accuracy of the correction results,the geometric correction efficiency is greatly improved.(2)An improved registration method based on Bayesian optimization model is proposed.In order to obtain high quality stitching results,in the process of registration,Bayesian optimization model is proposed to remove the incorrect local matching;in the process of alignment,based on the mesh optimization and alignment,from the perspective of shape correction,using shape preserving method for reference,similar transformation constraints are added to the whole stitched image to correct the shape of the stitched image and reduce the projection distortion and weight The algorithm has strong robustness.(3)In this thesis,a method of plane selection of datum projection image based on topological analysis is proposed.At present,most of the mesh optimization methods use local constraints to solve local problems,which is not suitable for splicing multiple images,and there will be error accumulation.However,the adjustment of beam method is only to obtain the pseudo plane.When splicing multiple images,the pseudo plane violates the strict geometric model and easily leads to error accumulation.In view of the above problems,this paper proposes a topological analysis based plane selection of datum projection image,and then global alignment.The advantages of our method are illustrated by experiments.(4)In this thesis,a non uniformity correction method(NWWF)is proposed.Because it is swing scan imaging,the detection pixels corresponding to the overlapped area of the adjacent image are different,so non uniformity correction is needed.In order to solve the problem of non uniformity between images,a new non uniformity correction method(NWWF)is proposed based on the analysis of the non uniformity of the plane array swing scan aerial camera image.By comparing with histogram regulation method and Wallis filtering method,the four non uniformity correction evaluation indexes are optimal,which verifies the effectiveness and robustness of NWWF algorithm.