利用星載InSAR生成DEM方法研究.pdf

1、論文題目：利用星載 InSAR 生成 DEM 方法研究 專 業(yè)：大地測量學(xué)與測量工程 碩 士 生：陳衛(wèi)南 (簽名) 指導(dǎo)教師：姚頑強 (簽名) 摘要 數(shù)字高程模型(Digital Elevation Model, DEM)描述的是地形表面高程信息， 它在土木工程應(yīng)用、景

2、觀設(shè)計與城市規(guī)劃和軍事目標建設(shè)等方面有著重要的作用。其中 1:50000高精度 DEM 數(shù)據(jù)在土地利用現(xiàn)狀調(diào)查、專題圖制作、更新更小比例尺數(shù)據(jù)等方面有著廣泛的應(yīng)用。 InSAR 技術(shù)以任何天氣條件下獲取高精度大范圍干涉影像的優(yōu)勢正在被越來越廣泛的應(yīng)用于高精度 DEM 生成。InSAR 衛(wèi)星在對地面目標進行成像觀測時會產(chǎn)生主星位置和速度、斜距、基線長度以及非模糊相位等一系列的系統(tǒng)誤差，而在干涉數(shù)據(jù)處理過程中各系統(tǒng)誤差主要表現(xiàn)為干涉相位誤差

3、、基線測量誤差和斜距測量誤差，三者一起影響著干涉結(jié)果的精度。 針對干涉相位中的噪聲誤差，提出一種基于 BEMD-Goldstein 的干涉相位濾波處理方法。利用二維經(jīng)驗?zāi)B(tài)分解(bidimensional empirical mode decomposition，BEMD)算法對干涉圖進行分解；采用分解后的結(jié)果對干涉圖影像進行局部信噪比的估算，將局部信噪比作為 Goldstein 濾波新的濾波因子對分解后的噪聲分量進行濾波處理；最終將濾

4、波結(jié)果進行重構(gòu)處理生成新的干涉圖，用于后期數(shù)據(jù)處理。 針對山區(qū)等測繪困難區(qū)域獲取地面控制點困難的問題，提出基于參考 DEM 進行干涉定標的方法。首先，基于斜距-多普勒模型將參考 DEM 模擬得到 SAR 圖像坐標系下的模擬 SAR 影像，通過選取兩景影像之間的同名點建立對應(yīng)關(guān)系，獲取 SAR 影像上對應(yīng)點的高程信息；然后，將基線參數(shù)進行三維坐標分解對干涉定標模型進行優(yōu)化，引入牛頓下山迭代法對優(yōu)化后的定標方程進行解算處理， 提高敏感度方程

5、的解算速度與精度。使用模擬和真實的干涉相位數(shù)據(jù)對提出的濾波算法進行驗證分析。結(jié)果表明，算法在去除相位噪聲和細節(jié)信息保持方面要優(yōu)于其他濾波方法，可以為 InSAR 技術(shù)獲取DEM 提供更精確的干涉相位。同時，采用陜西省閻良地區(qū)的 TanDEM-X 數(shù)據(jù)對基線定標算法進行了驗證，并用實測控制點和參考 DEM 對監(jiān)測結(jié)果進行了對比驗證。驗證結(jié)果表明，檢查點的高程均方根誤差為 1.95m，而整個研究區(qū)域的均方根誤差為 2.03m，滿足 1:50

6、000 比例尺測圖精度的需求。此外，論文還使用山西太原以及西藏雙湖地區(qū)的TanDEM-X 影像進行了實驗。實驗表明，論文方法在山地和高山地等地形復(fù)雜地區(qū)都可以獲得高精度 DEM 結(jié)果。論文對將 InSAR 技術(shù)工程化應(yīng)用于 DEM 生產(chǎn)具有重要的參Subject: Study on the generation of DEM using Spaceborne InSAR Specialty: Geodesy and Surveying

7、Engineering Name : Chen Weinan (Signature) Instructor: Yao Wanqiang (Signature) ABSTRACT Digital elevation model (DEM) is a description of the t

8、errain surface elevation information. It plays an important role in the civil engineering applications, the city landscaping and planning, the military construction, etc. Particularly, the 1:50000 high precision DEM data

9、 has a wide range of applications in the current situation of land use survey, thematic map production, update the smaller scale DEM data and other aspects. InSAR method has been widely applied in high precision DEM acqu

10、isition due to the advantages of wide monitoring range, high monitoring accuracy, all weather monitoring and other advantages.The research shows that Radar satellite includes the system errors of position and velocity, r

11、ange distance measurement, baseline measurement and no fuzzy phase in the imaging observation of ground targets. These system errors will show as interferometric phase error and baseline error during the InSAR processing

12、 which affecting the accuracy of the final results. According to the interferometric phase error, The BEMD-Goldstein interferometric filtering algorithm was proposed in this paper. At First, the bidimensional empirical

13、mode decomposition (BEMD) algorithm was used for interference graph decomposition; then, the local signal-to-noise ratio of the interferometric phase was estimated by decomposition results, which will be the new factor i

14、n the Goldstein filtering algorithm for the decomposition filtering. Finally, the filtering results were reconstructed for a new interferogram which was used for the last processing. Secondly, aiming at the problem of ob

15、taining ground control point in mapping difficult areas, a new method of interferometric calibration based on reference DEM was proposed. Based on the slant range and Doppler model for reference DEM, realtionship was est

16、ablished between SAR and simulation SAR for obtaining the corresponding elevation information in SAR image. Then the elevation was used for the baseline calibration processing. In order to improve the accuracy of the sen