ENGLISH

12卷/2期

12卷/2期

華藝線上圖書館

Pages:

107-119

論文名稱

利用衛星雷達影像分析臺灣西部水線變遷

Title

Analysis change detection waterline in west Taiwan using satellite SAR imagery

作者

王秀雯;王志添;陳錕山;林延郎

Author

Hsiu-Wen Wang, Chih-Tien Wang,Kun-Shan Chen,Yan-Lang Lin

中文摘要

本研究利用ERS-1 與ERS-2 衛星雷達進行台灣西部海岸水線萃取與變遷分析;由桃園觀音至屏東東港沿海地區長約400 公里,觀測時間為1996 年與2005 年間隔10 年共計23 觀測航次。輔以光學衛星影像、水利署水深資料與中央氣象局潮位站潮位觀測資料,透過雷達影像進行萃取,獲取水陸交界之水線資料,經套疊水深地形資料並配合潮位資料與光學影像有效偵測出大範圍海岸長期變遷情形。本研究特別針對芳苑地區、海豐島洲、外傘頂洲進行深入分析,結果顯示在同一潮位下(約0.8 公尺)外傘頂洲面積由2005年縮小為1996 年的1/3,東南端向東南漂移約700 公尺,此外也發現2005 年北港溪出海口沙洲與外傘頂洲逐漸往內陸靠近的趨勢;在同一潮位下約0.5 公尺)海豐島洲地區1996 年至2005 年之間面積變化情形不大,但沙洲南移約1.5 公里,其沙洲亦有向內陸靠近的趨勢。總結本研究成果可以發現,利用長期密集雷達影像觀測與水線萃取,配合潮位資料,可以有效獲取潮間帶水深的地形概況與瞭解水線位移或沙洲面積變化情形。

Abstract

This study applied satellite SAR images from ERS-1 and ERS-2 for water line extraction and change detection along the west costal area, covering from Kuan-in, Taoyuan to Tung-Kang, Pintung a total of about 400 km long. The images were acquired in the years of 1996 and 2005 with 10 years time span with 23 image tracks (total 92 image sets of 100 km by 100 km) In particular, the environmental sensitive areas of Fang-Yuan, Hai-Feng-Dao Chou, and Wai-San-Ting Chou, were chosen for detailed analysis. In addition to SAR images, we also incorporated optical satellite images, water depth map from Water Resource Bureau, and tidal records from tidal stations operated by Central Weather Bureau. This is important to ensure all the water line can be calibrated to the same tidal level. From the results, it is found that Wai-San-Ting Chou moved southward about 700 meters during 10 years period and it was shrunk to just one-third of its size in 1996. It is also found that the surroundings costal waters of Wai-San-Ting Chou and estuary of Pei-Kang River moved inward to west costal. The water channel was becoming more deposited as a result. Finally, Hai-Feng-Dao Chou itself moved southward about 1.5 km although its size remained quite the same during 1996 and 2005, and it also presented a clear tendency of inward moving. From the results we reported here, it is concluded that satellite remote sensing by SAR, aided by ground tidal data, bathematric map, and optical images, provides an effective and efficient tool for costal water changes in terms of large area coverage and long time span.

關鍵字

雷達影像、海岸線變遷偵測、水線萃取

Keywords

Synthetic Aperture Radar (SAR), coastline change detection, waterline extraction

附件檔名

華芸線上圖書館

N / A

備註說明

200706-12-2-107-119

Pages:

121-131

論文名稱

粗糙集方法應用於水稻田辨識之研究

Title

Rice Paddy Identification Using Rough Set Theory

作者

陳承昌;史天元

Author

C.C. Chen,T.Y. Shih

中文摘要

本研究以粗糙集方法進行水稻田之辨識作業,採用嘉義地區多時段Formosat-2 影像及新竹地區多時段SPOT 影像為資料來源。實驗中,將粗糙集方法與高斯最大似然分類法及倒傳遞類神經網路進行分類成果比較。由實驗成果顯示,粗糙集方法於嘉義實驗區其整體精度為86.947%、Kappa 值為0.73826;於新竹實驗區其整體精度為81.44%、Kappa 值為0.61448。兩實驗區中,粗糙集方法的分類精度皆優於高斯最大似然分類法,但較倒傳遞類神經網路為差。

Abstract

This study investigates the application of the Rough Set Theory for image classification. The images used for the experiment include multi-temporal Formosat-2 images of the Chiayi area and multi-temporal SPOT images of the Hsinchu area. Gaussian Maximum Likelihood Classification and Back-Propagation neural network are used for comparison. The overall accuracy for Rough Set Theory is 86.947% for Chiayi and 81.44% for Hsinchu. The kappa index is 0.73826 for Chiayi and 0.61448 for Hsinchu. In terms of the classification accuracy, Rough Set Theory is shown to be better than Gaussian Maximum Likelihood Classification but inferior to Back-Propagation neural network for Chiayi and Hsinchu area.

關鍵字

衛星影像、多光譜、影像分類

Keywords

Satellite imagery, multi-spectral, image classification

附件檔名

華芸線上圖書館

N / A

備註說明

200706-12-2-121-131

Pages:

133-144

論文名稱

利用合成陣列技術進行雷達影像方位方向之聚焦處理

Title

Radar Image Focusing Process in Azimuth Direction Using Synthetic Array Technique

作者

曾裕強;朱得銘

Author

Yu-Chang Tzeng, De-Ming Chu

中文摘要

合成口徑雷達可利用聚焦處理的技術大幅改善真實孔徑雷達在方位方向的解析度,進而提高雷達系統在遙測應用上的實用性。在傳統上,合成口徑雷達利用載具以定速度移動而對目標物產生杜卜勒頻移,再利用時間域的傅立葉轉換而達到提高方位方向解析度之目的。國立聯合大學電子工程學系遙測影像處理研究室與國立中央大學太空及遙測研究中心微波遙測實驗室已共同設計完成一合成口徑雷達地面遙測系統。此系統在前一階段的研究中,已由中央大學的研究團隊利用頻率調變波-步階頻率連續波的技術發射電磁波,並對接收訊號進行反離散傅立葉的轉換,而達到距離方向聚焦的目的。然而,因此系統無移動裝置故無法對目標物產生杜卜勒頻移,以致在方位方向的聚焦處理上發生困難。因此,本論文之主要工作即在於提出一有效的方法以進行本系統在方位方向之聚焦處理。由於本系統與合成陣列之架構類似,故本論文提出利用合成陣列技術藉由一虛擬之位移速度將時間域的傅立葉轉換等效為空間域的傅立葉轉換,以達到方位方向聚焦的目的。首先,本論文將所提出之方法以實際之系統參數利用電腦模擬所產生之回波訊號來驗證其可行性。模擬結果顯示,此一方法在方位方向無法達到聚焦的目的。接著,本論文再對此系統實際測試所接收的資料,依本論文所提出之方法進行方位方向的聚焦處理。實驗結果與電腦模擬所獲得之結果相同,顯示此一方法在方位方向無法達到聚焦的目的。於是,本論文再對實際之系統參數作一驗證,發現此一系統所設計之參數,在距離方向取樣點過多而在方位方向卻是取樣點過少,以致在方位方向無法產生聚焦的效果。最後,本論文再以修正後之系統參數利用電腦模擬所產生之回波訊號來驗證本論文所提出之方法。模擬結果顯示,此一方法確實可達到方位方向聚焦的目的。總而言之,本論文已成功解決無移動裝置之合成口徑雷達地面遙測系統在方位方向無法聚焦的困難。同時,利用合成陣列技術藉由一虛擬之位移速度將時間域的傅立葉轉換等效為空間域的傅立葉轉換,使得傳統上用以進行方位方向聚焦的作法仍然可以使用,而無須付出其他多餘的代價。

Abstract

Synthetic aperture radar (SAR) which adopts a focusing process to improve the spatial resolution in azimuth direction of the real aperture radar (RAR) brings the use of radar system in remote sensing applications into practical. Traditionally, SAR platform moving with a constant speed along azimuth direction results in a Doppler frequency shift relative to a target on the ground. A time domain Fourier Transform is then applied so that the spatial resolution in azimuth direction is improved. The Remote Sensing Image Processing Lab at the Department of Electronic Engineering in the National United University cooperated with the Microwave Remote Sensing Lab at the Center for Space and Remote Sensing Research in the National Central University to design a ground based SAR remote sensing system. In the previous studies, which are performed by the research group in the National Central University, the step frequency continuous wave technique was adopted to modulate the transmitted electromagnetic waves so that Inverse Discrete Fourier Transform could be applied to the received radar echoes and image focusing in the range direction were achieved. However, without Doppler frequency, image focusing in the azimuth direction can not be realized by making use of the conventional approach because that this system has no moving mechanism. Therefore, this paper aims to propose an effective approach to conduct SAR image focusing process in azimuth direction for the ground based SAR remote sensing system. Because the architecture of this system is similar to that of synthetic array, this paper propose to apply synthetic array technique to transfer time domain Fourier Transform into spatial domain Fourier Transform with a virtual speed of the system so as to attain SAR image focusing in azimuth direction. At first, in this paper, a computer simulation according to the system parameters designed in the precious studies is done to verify the feasibility of this approach. Simulation result shows that this approach fails to perform SAR image focusing in azimuth direction. Then, this approach is applied to the real radar image acquired by the ground based SAR system. Experimental result indicates that this approach is still unable to achieve SAR image focusing in azimuth direction. Therefore, this paper attempts to re-design the system parameters. It is concluded that the failure of the proposed approach results from the sampling rates of the system which are over-sampled in the range direction and under-sampled in the azimuth direction. Finally, in this paper, a computer simulation according to the modified system parameters is done again to verify the feasibility of this approach. Simulation result shows that this approach does perform SAR image focusing in azimuth direction effectively. In conclusion, this paper has successfully overcome the difficulty of the SAR image focusing process in azimuth direction for a ground based SAR remote sensing system with no moving mechanism. The synthetic array technique is applied to transfer time domain Fourier Transform into spatial domain Fourier Transform with a virtual speed of the system so that the conventional SAR image focusing process in azimuth direction is still applicable without any extra efforts to be paid.

關鍵字

合成孔徑雷達、步階頻率連續波、合成陣列

Keywords

Synthetic Aperture Radar, Step-Frequency Continuous-Wave, Synthetic Array

附件檔名

華芸線上圖書館

N / A

備註說明

200706-12-2-133-144

Pages:

145-163

論文名稱

空間特徵分類器支援向量機之研究

Title

Space characteristic classifier of Support Vector Machine for satellite image classification

作者

雷祖強;周天穎;萬絢;楊龍士;許晉嘉

Author

Tsu-Chiang Lei, Tine-Yin Chou,Shiuan Wan,Long-She Yang, Jin-Jia Syu

中文摘要

如何選用適當的分類器一直是影像處理問題中經常被討論的一個研究重點,然而隨著衛星影像資料複雜度與資料量的增加,傳統線性分類器(例如:最大概似法、最短距離法等)已經無法達到有效分離類別之目標,因此本研究利用資料挖掘理論當中的-支援向量機法(Support Vector Machine, SVM),來做為探討遙測影像分類研究之新課題。本研究選擇了高解析度QuickBird 衛星影像及紋理資訊(Texture Information)做為影像分類時之資料來源,並利用最大概似法與支援向量機法來達到分類的目的。研究成果顯示,影像透過多組紋理並進行分類後之成果,整體來說,是支援向量機的分類精度優於最大概似法,精準度值較高也較穩定,不會像最大概似法有高低震盪的情形發生。而且就影像個別類別區塊化的能力來說,也是以支援向量機的成果較佳,特別是在「水稻」這個類別上面。因此本研究特別發現以支援向量機分類方法處理加入紋理資訊的影像,整體精度將會是優於傳統最大概似分類法之結論。

Abstract

It is of considerable interest to find an optimal classifier that has been discussed in the field of spatial information. In essence, there are many image classification methods, e.g. Maximum likelihood (MLH), K-nearest…. However, most of the linear classifiers are not capable of handling the complexity and the huge amount of the very high resolution image data. Thus, Support Vector Machine (SVM) is one of the powerful non-linear data mining classifier which is adopting to resolve the classification problems in this study. The high resolution QuickBird satellite images with additional texture information are the study material. The MLH method is used as a parallel study for the comparison on overall accuracy. The contribution of this study found that the overall accuracy of SVM is stable than that of MLH. More specifically, the overall accuracy of SVM is 87.3% (Kappa=0.8416) which is apparently higher than that of MLH (overall accuracy of SVM is 83.73% with Kappa= 0.7994). On the other hand, SVM can display better classification outcomes in the image pattern of “paddy rice” than that of MLH. In fact, the additional texture information can deal with noise effectively. The study find out that SVM can potentially perform higher image classification ability than the conventional MLH method.

關鍵字

影像分類、紋理資訊、支援向量機

Keywords

Image Classification, Texture Information and Support Vector Machine

附件檔名

華芸線上圖書館

N / A

備註說明

200706-12-2-145-163

Pages:

165-177

論文名稱

空載光達作業及品管流程之研究

Title

The Production Flow and Quality Control of Digital Elevation Model with Airborne Lidar

作者

何心瑜;史天元

Author

Hsin-Yu Ho, Tian-Yuan Shih

中文摘要

在空載光達產製數值高程模型與數值表面模型之過程中,所有的步驟皆會影響最終產品品質。在不同階段採用不同之檢驗標準,或採用不同工序,使用者可依用途選擇適合之產品。本研究僅以空載光達產製點雲之作業為探討對象,整理現有之作業流程,並針對一般使用目的之作業流程設計查核項目和時機,以為品質管制之手段。本研究將空載光達作業流程分為任務規劃、資料獲取和資料處理,其中資料處理又分為點雲解算和點雲分類與編修。依據流程,本研究擬定九個查核點,以供品質檢驗時之參考。

Abstract

Each element in the production chain of airborne lidar operation will inevitably influence the final quality of the product. By selecting different parameter values in each check item, and adopting different procedures, one can define the quality level of the product required for the application. This study investigates the production flow of airborne lidar for the digital elevation model and digital surface model. The procedures and different phases of the operation are analyzed. A series of check items for quality assurance and their schedule are proposed. Three phases are identified, mission planning, data collection, and data processing. In the data processing, it is further divided into point cloud generation, classification, and editing.

關鍵字

密度、合理性比較、交叉比對

Keywords

density, logical analysis, cross validation

附件檔名

華芸線上圖書館

N / A

備註說明

200706-12-2-165-177

Pages:

179-195

論文名稱

整合光達資料與二維路網重建三維道路模型

Title

Fusion of LIDAR data and road networks for the reconstruction of 3D road models

作者

陳良健;羅詔元

Author

Liang-Chien Chen, Chao-Yuan Lo

中文摘要

因應三維道路模型於空間資訊領域的重要性日益增加,本研究藉由整合光達資料與二維路網,自動重建三維道路模型。研究內容包含:初始模型建立、精確模型建立與模塑品質評估。初始模型部份,以二維路網位相關係與光達資料產生模型路面的初始高程。精確模型部份,本研究提出路網高程平差程序,進一步修正道路縱斷面豎曲線與路網連結處高程,產生精確道路模型。模塑品質評估部份,研究測試區包含單層與多層路網,成果以「點對模型」與「模型對模型」兩種方式進行驗證,最後再以坡度與坡度差檢核觀察模型與路面點雲間的空間分佈一致性。

Abstract

The 3D road modeling becomes an important task in the geoinformatic realm. The proposed scheme integrates LIDAR data and road networks to automatically reconstruct 3D road models. The whole process includes three parts: initial modeling, precise modeling, and validation. First, the elevation of the model surface is initially derived from LIDAR data. Then, the vertical alignment of each road segment is modified by line fitting. In the second part, the continuity in height, slope, and slope difference of 3D road models are fine-tuned with least squares adjustment. Finally, the validation is done to examine the consistency between point clouds and the generated model, the difference between the reference model and the generated model, and the rationality of the generated road profiles.

關鍵字

道路模型、重建、光達資料、二維路網

Keywords

road modeling, reconstruction, LIDAR data, road networks

附件檔名

華芸線上圖書館

N / A

備註說明

200706-12-2-179-195

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