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Researches On Preprocessing For Shooting Range Images And Monocular Measurements For Targets' Movement

Posted on:2008-02-24Degree:DoctorType:Dissertation
Country:ChinaCandidate:H DiFull Text:PDF
GTID:1102360242999389Subject:Aeronautical and Astronautical Science and Technology
Abstract/Summary:PDF Full Text Request
The main researches in this dissertation are the falling attack angle and velocity measurement of the submunition of cluster warhead and the three-dimensional trajectory and velocity measurement of moving point targets from a moving monocular camera. The other researches are correlative preprocessing methods for shooting range degraded images to enhance the target feature.It is crucial to measure the attack angle and velocity of the submunition falling to the ground for analyzing the reason of the submunition rebounding and evaluating the destruction effectiveness of the cluster warhead. A few even only one submunition images can be captured even by high-speed camera sometimes because they are falling very fast; furthermore the images are often motion blurred. The falling attack angle and velocity of the submunition are difficult to be accurately measured by general methods. The proposed measurement method from a single motion blurred image calculates the attack angle and velocity of the high-speed moving targets by analyzing the target motion blur band's characteristic.At present in out country weapon shooting ranges, optical measurement mainly depends on the ground-based measuring stations. But in the ball cartridge test of a new kind cruise missile, because of its low ambient altitude and far voyage, the existing measuring stations can not cover all its voyage, a measurement aeroplane is used to track and observe it. Without assistant means, two cameras are usually demanded to realize the intersection measurement for three-dimensional position of point targets. But in our mission, only monocular sequence images can be obtained. Two position measurement methods for moving point targets from a moving camera are proposed. Supposing the target keeping to some movement rule as target position restriction information, using the velocity difference between the aeroplane and target, accurate monocular measurements for three-dimensional position and velocity of the hedgehopping and far voyage flight target are realized by space searching or virtual intersection without adding ground-based measuring stations, range information of the target or cooperative marks on the target. The proposed methods are able to solve the difficult problem of measuring the three-dimensional ballistic trajectory and velocity of a ball cartridge which can not be equipped with the measurement equipment. This can improve the test capability of shooting ranges and save a great deal of expense.Motion blur, low contrast, evident noise and other degradations are usually existent in the shooting range images. In order to improve image quality and enhance the target feature, a series of methods of image restoration, supperresolution, noise calibration and elimination are studied.The main contents and originalities of this dissertation are as follows. (1) Regularized restoration methods and blind restoration methods are studied. An analytic superresolution algorithm is improved.(2) Dark current noise and random noise calibration and elimination methods for CCD cameras are proposed. The influence of noise on edge position is discussed. For 16-bit infrared images and true color images, a piecewise gray-scale transform enhancement algorithm and a false color enhancement algorithm are proposed.(3) Others' algorithms are extended. For uniform linear motion blur along arbitrary direction and uniform rotation blur, degeneration models and restoration models are established based on Z transform; from a single motion blurred image, the blur extent is estimated by means of derivation and correlation and the rotation center is automatly found.(4) A method for measuring the attack angle and velocity of the submunition falling to the ground from a single motion blurred image is proposed. Based on blur band's characteristic, the relationship among the band width, blur extent and attack angle is deduced. The velocity and attack angle of high speed moving tagets are calculated by using the subpixel technique.(5) Two monocular methods of three-dimensional position and velocity measurement for a moving point target by a moving camera are proposed. Without range information of the target or cooperative marks on the target, supposing the target following some movement rule, with the velocity difference between the aeroplane and target, accurate measurement for three-dimensional trajectory and velocity are realized by space searching or virtual intersection from sequence images of a single camera. Without distance measurement or other assistant means, the proposed methods resolve the problem that in the shooting range a single moving camera can only observe the moving target and can not measure the motion parameters, and expand the videogrammetry application range.
Keywords/Search Tags:Image Restoration, Image Superresolution, CCD Noise Calibration and Elimination, Image Enhancement, Motion blur, Attack Angle Measurement, Monocular Position Measurement
PDF Full Text Request
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