本文選題：非常規(guī)航攝影像 + 影像仿真��； 參考：《武漢大學》2013年博士論文

【摘要】：航空攝影測量是獲取及更新地理信息的重要手段,是基本比例尺地形圖的主要成圖方式,已經(jīng)成為我國基礎測繪的通用作業(yè)模式。隨著科技的發(fā)展,攝影測量有了長足的發(fā)展。輕小型飛行平臺已經(jīng)應用于航空攝影測量,使其作業(yè)形式更加靈活,但也帶來了影像姿態(tài)不穩(wěn)定的新問題。本文圍繞非常規(guī)航攝影像的定向和定位這一主線,針對其排列不規(guī)則、姿態(tài)變化大引起的新問題,以空中三角測量為基礎,深入研究了適用于非常規(guī)航攝影像的定向方法,并對其定位精度進行了深入探討。本文的主要研究內容和創(chuàng)新性成果如下： (1)改進了非常規(guī)航攝影像的模擬方法。為提高處理效率,改進了影像模擬方法,提出以面元為處理單位的反解法對航攝影像進行模擬。首先選取待模擬區(qū)域對應的DEM和DOM數(shù)據(jù),根據(jù)航攝條件設置影像的內外方位元素；其次根據(jù)區(qū)域的地形特點將影像劃分為面元；然后對面元四角的像素進行高程迭代以獲取其對應地面點的平面位置,并建立面元與地面格網(wǎng)的近似仿射變換關系；最后基于仿射變換計算面元上所有像素對應的地面平面位置,并在DOM上獲取灰度值。對平地和丘陵地的多種攝影條件下的航攝影像模擬結果表明,本文提出的影像模擬方法能夠模擬各種攝影條件下的航攝影像,相比逐像素的影像模擬方法,處理效率提高了10倍左右。 (2)分析了航攝影像的匹配精度。通過對模擬的航攝影像進行高精度影像匹配,評價影像匹配的精度。試驗結果表明,對影像間幾何變形小的影像,匹配精度優(yōu)于1/6像素；對影像間幾何變形較大的影像,匹配精度一般不超過0.4像素。這一統(tǒng)計結果可作為影像自動量測的精度估值以及檢驗指標。 (3)針對影像間存在大旋角的立體像對,提出了以奇異值分解約束本質矩陣獲得未知數(shù)初值的嚴格相對定向方法。首先構建影像間的本質矩陣,采用傳統(tǒng)的8點法線性求解本質矩陣元素；其次顧及本質矩陣的秩虧特性,采用奇異值分解方法對本質矩陣進行降秩約束；然后從經(jīng)約束的本質矩陣元素導出相對定向元素的初始值；最后將初始值帶入到基于上下視差的嚴格相對定向模型進行迭代求解。對模擬影像、常規(guī)航攝影像、非常規(guī)航攝影像的相對定向試驗表明,該方法適用于存在大旋角立體影像對的相對定向,能夠滿足實際生產重構立體模型的精度需求。 (4)針對存在大旋角、大傾角的影像模型,提出了基于平面旋轉的絕對定向方法。方法的核心是根據(jù)擬合平面的法向量的旋轉關系直接求解三維旋轉參數(shù)。首先對模型點在像方坐標系和物方坐標系下各自擬合出最佳平面,并計算平面的法向量；然后通過平面法向量的空間旋轉關系直接求解絕對定向角元素的初值；最后,將角元素初值連同由經(jīng)驗公式估計的比例系數(shù)初值一并代入絕對定向的嚴格模型進行絕對定向元素的精確求解。對模擬影像、航攝影像、近景影像的試驗結果表明,本文方法適用于存在大旋轉角的影像模型的絕對定向,定向精度滿足實際生產需求。 (5)分析了解析空中三角測量各個環(huán)節(jié)的誤差傳播特性,統(tǒng)計了非常規(guī)影像定位定向的精度估值。通過對各種攝影條件下的模擬航攝影像區(qū)域網(wǎng)的平差處理,給出非常規(guī)航攝影像定位精度的估算公式。
[Abstract]:Aero photogrammetry is an important means of obtaining and updating geographic information. It is the main mapping method of basic scale topographic map. It has become the general operation mode of basic surveying and mapping in our country. With the development of science and technology, photogrammetry has made great progress. The light and small flying platform has been applied to aero photogrammetry to make its operation form more In this paper, based on the orientation and positioning of the unconventional aerial photography, this paper focuses on the orientation and positioning of the unconventional aerial photography, aiming at the new problems caused by the irregular arrangement and the large change of attitude. Based on the aerial triangulation, the orientation method suitable for the unconventional aerial photography is deeply studied and its positioning accuracy is advanced. The main research contents and innovative achievements of this paper are as follows:
(1) improved the simulation method of the unconventional aerial photography image. In order to improve the processing efficiency and improve the image simulation method, the inverse solution of the surface element as the processing unit is proposed to simulate the aerial photography. First, we select the DEM and DOM data corresponding to the simulated region, set the internal and external elements of the image according to the aerial conditions, and then according to the area of the area. The image is divided into a surface element, and then the pixel of the four corner of the opposite element is iterated to obtain the plane position of its corresponding ground point, and the approximate affine transformation relationship between the surface element and the ground grid is established. Finally, the ground plane position corresponding to all pixels on the surface element is calculated based on the affine transformation, and the gray value is obtained on the DOM. The simulation results of aerial photography under various photographing conditions in flat and hilly areas show that the proposed image simulation method can simulate the aerial photography under various photographing conditions. Compared with the pixel by pixel image simulation method, the processing efficiency is increased by about 10 times.
(2) the matching accuracy of aerial photography is analyzed. The accuracy of image matching is evaluated by matching the simulated aerial images with high precision images. The experimental results show that the matching precision is better than 1/6 pixels for small images with small geometric distortion, and the matching precision is generally not more than 0.4 pixels for the image with large geometric distortion between images. The results can be used as the accuracy estimation and inspection index for automatic image measurement.
(3) in view of the stereoscopic image pairs with large rotation angles between images, a strict relative orientation method is proposed to obtain the initial values of unknowns by the singular value decomposition constraint essential matrix. First, the essential matrix between the images is constructed, and the traditional 8 point method is used to solve the essential matrix elements linearly. Secondly, the rank deficiency characteristics of the essential matrix are taken into account, and the singular value decomposition square is adopted. The method has a reduced rank constraint on the essential matrix, and then derives the initial values of the relative orienting elements from the essential matrix elements that are constrained. Finally, the initial values are introduced into the strict relative orientation model based on the upper and lower parallax. The method is applicable to the relative orientation of stereo image pairs with large swirling angles, which can meet the accuracy requirement of reconstructing 3D models in actual production.
(4) an absolute orientation method based on plane rotation is proposed for the image model of large rotation angle and large dip angle. The core of the method is to solve the three dimensional rotation parameters directly according to the rotation relation of the normal vector of the fitting plane. First, the best plane of the model point in the image square coordinate system and the matter square coordinate system is fitted together, and the method of calculating the plane is calculated. The initial value of the absolute orientation angle element is solved directly by the space rotation relation of the plane normal vector. Finally, the exact solution of the absolute orientation element is solved with the initial values of the angular elements together with the initial values estimated by the empirical formula into the absolute orientation. The experimental results show that the method is applicable to the absolute orientation of the image model with large rotation angle, and the orientation accuracy meets the actual production demand.
(5) the error propagation characteristics of each link in the aerial triangulation are analyzed, and the accuracy estimation of the unconventional image location orientation is calculated. The estimation formula of the location precision of the unconventional aerial photography image is given through the adjustment of the simulated aerial photography area network under various photographing conditions.
【學位授予單位】：武漢大學
【學位級別】：博士
【學位授予年份】：2013
【分類號】：P231

【參考文獻】

相關期刊論文 前10條

1 林宗堅;;UAV低空航測技術研究[J];測繪科學;2011年01期

2 龔輝;江剛武;姜挺;;基于單位四元數(shù)的絕對定向直接解法[J];測繪通報;2007年09期

3 袁修孝;高精度攝影測量加密精度的若干探討[J];測繪學報;1991年03期

4 袁修孝;;POS輔助光束法區(qū)域網(wǎng)平差[J];測繪學報;2008年03期

5 陳義;陸玨;鄭波;;近景攝影測量中大角度問題的探討[J];測繪學報;2008年04期

6 胡永勝;李海鴻;;絕對定向的一種線性解法[J];武測科技;1990年03期

7 張鈞,柳健,劉小茂;利用羅德里格矩陣確定三維表面重建中的絕對定向模型[J];紅外與激光工程;1998年04期

8 江剛武;王凈;張銳;;基于單位四元數(shù)的絕對定向直接解法[J];測繪科學技術學報;2007年03期

9 官云蘭;程效軍;施貴剛;;一種穩(wěn)健的點云數(shù)據(jù)平面擬合方法[J];同濟大學學報(自然科學版);2008年07期

10 張祖勛,張劍清,張力;數(shù)字攝影測量發(fā)展的機遇與挑戰(zhàn)[J];武漢測繪科技大學學報;2000年01期

相關博士學位論文 前2條

1 明洋;特殊航空影像自動匹配的關鍵技術研究[D];武漢大學;2009年

2 張影;三線陣CCD立體測繪相機總體技術研究[D];長春理工大學;2009年

，

本文編號：1997368