地面沉降論文：PS探測(cè)方法的改進(jìn)及其在天津地區(qū)沉降監(jiān)測(cè)中的應(yīng)用

1、地面沉降論文：PS探測(cè)方法的改進(jìn)及其在天津地區(qū)沉降監(jiān)測(cè)中的應(yīng)用【中文摘要】由于受人為和自然因素的影響,地面沉降等各種地質(zhì)災(zāi)害正逐步影響著人們的生活環(huán)境和人類社會(huì)、經(jīng)濟(jì)發(fā)展。隨著城市化進(jìn)程加快,人口快速集中,城市地區(qū)的地面沉降更加突出。在我國(guó)自上世紀(jì)20年代出現(xiàn)地面沉降以來,目前已發(fā)展成為區(qū)域性分布的格局。天津市受過度抽取地下水資源的影響已成華北地區(qū)的沉降中心。InSAR技術(shù)與傳統(tǒng)的水準(zhǔn)測(cè)量、GPS等監(jiān)測(cè)地面沉降方式相比,具有覆蓋廣、全天候和低成本的優(yōu)勢(shì),但傳統(tǒng)D-InSAR技術(shù)在測(cè)繪地表沉降中受時(shí)空失相干和大氣影響,無法適應(yīng)長(zhǎng)時(shí)間序列的緩慢地表形變的測(cè)量工作。PSInSAR技術(shù)提取區(qū)域中長(zhǎng)時(shí)間

2、保持穩(wěn)定、相位質(zhì)量好的永久散射體來提取時(shí)間序列地表形變信息,克服了常規(guī)D-InSAR的不足。但是PSInSAR技術(shù)在PS點(diǎn)的選取、網(wǎng)形的構(gòu)建方法和非線性估計(jì)等方面還需要完善,同時(shí)基于高分辨率TerraS AR影像的PS干涉技術(shù)應(yīng)用也是一個(gè)新的課題。本文旨在對(duì)PSInSAR技術(shù)做局部改進(jìn)的基礎(chǔ)上,使用高分辨率影像獲取了天津地區(qū)的地面沉降數(shù)值。具體有以下幾方面的工作。1、本文在查閱大量文獻(xiàn)的基礎(chǔ)上對(duì)D-InSAR的技術(shù)原理和數(shù)據(jù)處理流程,以及實(shí)踐應(yīng)用進(jìn)行了全面系統(tǒng)性的總結(jié)。對(duì)基于高相干性點(diǎn)目標(biāo)分析技術(shù)監(jiān)測(cè)長(zhǎng)時(shí)間序列地表形變的代表方法進(jìn)行了介紹。2、本文基于TerraSAR-X高分辨率數(shù)據(jù)對(duì)常用的P

3、S探測(cè)方法進(jìn)行了實(shí)驗(yàn)研究,結(jié)果表明高分辨率數(shù)據(jù)可顯著增加可探測(cè)PS點(diǎn)的數(shù)量,在實(shí)踐中應(yīng)對(duì)閾值的選擇做適當(dāng)調(diào)整。為了提高PS點(diǎn)的可靠性,本文提出基于時(shí)序在前面實(shí)驗(yàn)的基礎(chǔ)上提出基于振幅離差指數(shù)和時(shí)序振幅均值統(tǒng)計(jì)中值閾值的PS探測(cè)方法。3、對(duì)于因限制Delaunay三角網(wǎng)邊長(zhǎng)而產(chǎn)生的孤立PS點(diǎn),本文中采用最鄰近連接(CCM)的方法,使這些孤立點(diǎn)與最近的PS相連接,達(dá)到PS網(wǎng)絡(luò)閉合的。4、分析了傳統(tǒng)等權(quán)最小二乘的稀疏PS點(diǎn)相位解纏方法的不足,對(duì)按相位梯度最小來設(shè)置權(quán)重,進(jìn)行加權(quán)最小二乘相位解纏的方法進(jìn)行了實(shí)驗(yàn)研究,并基于不同的噪聲水平進(jìn)行的仿真模擬實(shí)驗(yàn),得到了可靠的實(shí)驗(yàn)結(jié)論。5、采用2009年3月至2

4、010年11月的17幅TerraSAR-X數(shù)據(jù),采用改進(jìn)的PSInSAR技術(shù)獲取了天津地區(qū)的地面沉降數(shù)據(jù),并與地面水準(zhǔn)數(shù)據(jù)進(jìn)行了驗(yàn)證。結(jié)果表明本文使用的方法切實(shí)可行,所獲取的沉降監(jiān)測(cè)結(jié)果可靠。【英文摘要】Geographical disasters, man-made or natural, like land subsidence, are influencing peoples living environment and development of human society and economy. With the speeding up of urbanization, larg

5、e quantities of population flooded into cities, where land subsidence became more serous. China detected land subsidence in 1920s, and now this problem has developed into a region-distributed phenomenon. Tianjin City has become the center of subsidence in North China due to the over-drained groundwa

6、ter.Compared with traditional leveling and GPS, InSAR technique has more advantages like better coverage and lower cost, and it can work for all-weather condition to monitor land subsidence. But traditional D-InSAR is liable to be influenced by decorrelation and atmosphere delay influence in mapping

7、 land subsidence, thus unable to be applied to slow deformation measurement of surface for a long time. On the other hand, PSInSAR technique is able to extract long-time stable permanent scatterers with good-qualitied phases to acquire time series of surface deformation information, which has overco

8、med the disadvantage of traditional D-InSAR. But PSInSAR technique needs to be perfected in the choosing of PS points, net-shaped construction method and nonlinear deformation estimation and so on. Meanwhile, Interferomtric technology of PS based on high resolution TerraSAR images is a new subject t

9、oo.This paper aims to acquire the value of land subsidence in Tianjian area by analyzing high resolution images, with some improvement to PSInSAR technique. The job includes the following parts:1.This paper is to analyze D-InSAR technique, its data-processing procedure and its application in practic

10、e in details based on a large amount of reviewed references. Then the paper is to introduce the representative ways based on high coherence point target analysis to monitor long-time series of surface deformation.2.This paper is based on the experimental research on TerraSAR-X high resolution data,

11、which explores regular PS detection method. The results show that high resolution data can dramatically increase the number of PS points, and in practice the choice of thresholds should be adjusted. In order to improve the reliability of PS points, this paper has improved the PS detection method on

12、the basis of initial experiment.3.As to the isolated PS points caused by restricted Delaunay triangle side, this paper is to adopt the method of closest connection method(CCM) which connects these isolated points with their closest PS so as to achieve the PS network closure. 4.After analyse the disa

13、dvantage of traditional unweighted Least Squares, phase gradient minimum criterion being used to set the weight, the weighted least squares phase unwrapping methods were studied through the simulation. Simulation experiment based on different levels of noise has been a reliable test conclusion.5.Thi

14、s paper is to extract the land subsidence data of Tianjian by analyzing 17 TerraSAR-X images scanned from March 2009 to Nov.2010 and adopting improved PSInSAR technique. The data are compared with the ground-level data, which indicates that this method works and the obtained subsidence data is relia

15、ble.【關(guān)鍵詞】地面沉降 TerraSAR-X 永久散射體雷達(dá)干涉測(cè)量 PS探測(cè)【英文關(guān)鍵詞】Land Subsidence TerraSAR-X PSInSAR PS detection【目錄】PS探測(cè)方法的改進(jìn)及其在天津地區(qū)沉降監(jiān)測(cè)中的應(yīng)用 摘要 6-7 Abstract 7-8 第1章 緒論 11-17 1.1 論文的研究意義 11-13 1.2 國(guó)內(nèi)外研究現(xiàn)狀 13-14 1.3 論文研究的主要內(nèi)容 14-16 1.4 論文的組織結(jié)構(gòu) 16-17 第2章 D-InSAR技術(shù) 17-35 2.1 InSAR的技術(shù)原理 17-20 2.2 單基線D-InSAR技術(shù)及其應(yīng)用于地面沉降監(jiān)測(cè)實(shí)

16、踐 20-29 2.2.1 單基線D-InSAR技術(shù)原理 20-26 2.2.2 單基線D-InSAR監(jiān)測(cè)地面沉降的實(shí)踐 26-29 2.3 單基線D-InSAR技術(shù)局限性 29-31 2.3.1 空間幾何失相干 30 2.3.2 時(shí)間失相干 30-31 2.3.3 大氣影響 31 2.4 基于相干點(diǎn)目標(biāo)分析的多基線D-InSAR方法 31-35 2.4.1 永久散射體(PS)方法 32-33 2.4.2 小基線子集(SBAS)方法 33 2.4.3 相干目標(biāo)(CT)分析方法 33-35 第3章 PS點(diǎn)的探測(cè)實(shí)驗(yàn)及結(jié)果 35-51 3.1 參考影像的選取和SAR影像的配準(zhǔn) 36-41 3.1.

17、1 配準(zhǔn)參考影像的選取 36-37 3.1.2 SAR影像的配準(zhǔn) 37-41 3.2 SAR影像的相對(duì)輻射校正 41-42 3.3 PS探測(cè)方法 42-49 3.3.1 相干系數(shù)閾值法 42-45 3.3.2 振幅離差指數(shù)閾值法 45-46 3.3.3 振幅和振幅離差指數(shù)雙閾值法 46-47 3.3.4 振幅離差指數(shù)和時(shí)序振幅均值統(tǒng)計(jì)中值閾值的PS探測(cè)方法 47-49 3.4 干涉像對(duì)組合與干涉圖生成 49-51 第4章 PS網(wǎng)絡(luò)建模、參數(shù)求解與沉降量提取 51-74 4.1 PS差分網(wǎng)絡(luò)的建立 51-53 4.2 PS鄰域差分建模 53-59 4.2.1 PS鄰域差分模型建立 53-55 4

18、.2.2 模型相關(guān)系數(shù)求解 55-59 4.3 參數(shù)估計(jì) 59-61 4.3.1 二維解空間搜索 59-60 4.3.2 鄰域差分網(wǎng)絡(luò)的優(yōu)化 60-61 4.4 網(wǎng)絡(luò)平差 61-63 4.5 殘余相位計(jì)算 63 4.6 稀疏PS點(diǎn)相位解纏 63-69 4.6.1 InSAR相位解纏理論 63-64 4.6.2 二維規(guī)則格網(wǎng)數(shù)據(jù)的相位解纏方法概述 64 4.6.3 二維離散分布數(shù)據(jù)的相位解纏方法 64-65 4.6.4 基于加權(quán)最小二乘的稀疏PS點(diǎn)相位解纏方法 65-66 4.6.5 基于加權(quán)最小二乘的稀疏PS點(diǎn)相位解纏的仿真實(shí)驗(yàn)及其結(jié)果 66-69 4.7 PS離散點(diǎn)數(shù)據(jù)的空間插值 69-70 4.8