ENGLISH

2 卷 / 3 期

2 卷 / 3 期

華藝線上圖書館

Pages:

1-13

論文名稱

空載合成孔徑雷達影像正射化

Title

Ortho-rectification of Airborne SAR Imagery

作者

王顯達 , 王志添

Author

H. T. Wang , Chih-Tien Wang

中文摘要

對空載合成孔徑雷達 SAR 影像之幾何校正,本文提出一正射化模式,此模式包含載具飛行參數求解與正射化程序,在飛行參數求解過程中,是將斜距間距及方位間距視為 SAR 已知系統參數,配合地面控制點幾何條件進行計算。在正射化過程中利用影像上在沿一回波線列斜距方向上斜距與觀測角變化為單調遞增關係,經檢核像元間變化獲取正射影像中疊置或陰影之區域。 在空載 SAR 影像研究範例中是以山區高度約為 350 公尺影像,使用地面控制點30 點進行載具飛行參數求解,並利用數位高程資料產生正射化SAR 影像,在此正射影像獲得地距誤差為 10 公尺左右,約為 SAR 原影像上1.5 個像元以內,同時得到地形造成 SAR 影像的疊置或陰影區域。

Abstract

We develop the ortho-rectification model to correct the airborne SAR slant-range imagery. This model include estimation of flight parameters and ortho-rectification procedure. We estimated the flight parameters with the ground control points, both the slant range spacing and azimuth spacing are known. We rectified the SAR imagery with a given digital elevation model and the estimated flight parameters. Here we have considered the effects of layover and shadow, we checked the variation of slant range and look angle along the direction of slant range. The tested data was taken over a mountainous area. The elevation within this area are about 350 m. We rectified the airborne SAR imagery with the digital elevation model data and 30 control points. The root mean square errors of slant range for ground control points and check points is about 6m. The resulting ground error is about 10m (1.5 pixels of slant range imagery) even in the mountainous area. The Paper is concluded by remarking on how to produce ortho SAR images which exhibit the phenomena of layover and shadow.

關鍵字

合成孔徑雷達、正射化、斜距、地距、疊置、陰影

Keywords

附件檔名

華芸線上圖書館

SAR image Ortho-rectification, Layover, Shadow

備註說明

199709-2-3-1-13

Pages:

15-24

論文名稱

以衛星量得之微波輻射來決定海面風速

Title

Determining Sea Surface Wind from Satellite Microwave Radiometric Measurements

作者

黃舜成 , 許明光 , Leonid M. Mitnik

Author

Shen-Cheng Huang , Ming-Kuang Hsu , Leonid M. Mitnik

中文摘要

本研究應用衛星微波遙測之技術與理論從事海面風速之估計。以臺灣四周海域為研究對象,使用被動式微波裝置 SSM/I(Special Sensor Microwave / Imager) 所收集之微波量測值(亮度溫度),嘗試以Schluessel and Luthardt (1991) 所發展的線性風速演算法與 Wentz(1992) 所發展的疊代風速演算法估計區域性海域之海面風速,期能為臺灣之海象測報作業提供一種異於傳統量測之方法。

Abstract

This study applies the technique and theory of satellite microwave remote sensing to determine the sea surface wind speed. The seas surrounding Taiwan will be an object of study. The microwave measurements (brightness temperature) were collected by the passive microwave instrument SSM/I (Special Sensor Microwave/Imager). The linear algorithm developed by Schluessel and Luthardt (1991) and the iterative algorithm developed by Wentz (1992) were used to estimate sea surface wind speed of local seas. The goals of this study are expected to supply a way to obtain sea-weather measurements that different from the traditional technique for Taiwan.

關鍵字

微波遙測、SSM/ I 、亮度溫度、海面風速、演算法

Keywords

Microwave Remote Sensing, SSM/I, Brightness Temperature, Sea Surface Wind, Algo­rithm

附件檔名

華芸線上圖書館

N / A

備註說明

199709-2-3-15-24

Pages:

25-35

論文名稱

碎形壓縮應用於遙測影像之研究

Title

A Study on Fractal Compression for Remotely Sensed Images

作者

蔡宗哲 , 史天元

Author

Tzong-Jer Tsai , Tian-Yuan Shih

中文摘要

本研究探討碎形壓縮於遙測影像之應用。研究中,分別使用碎形壓縮及傳統 JPEG 壓縮對兩幅 SPOT-2 全色態影像進行壓縮,針對各壓縮影像計算與原始影像間之關聯係數、均方根誤差、像元灰度值差異、及訊號雜訊比等統計指標,以比較其差異性。並嘗試利用碎形壓縮過程中區塊的分類,辨識出影像的特徵。成果顯示,碎形壓縮可得到較 JPEG 為大之壓縮比例,當壓縮比例達到一定程度時,碎形壓縮影像之品質將會優於 JPEG 。而較為均調的影像區域於壓縮後回復程度較佳。影像中灰值相近的大區域物件則較易分辨出其邊界。

Abstract

Two fractal-based compression procedures are investigated and compared with the conventional JPEG procedure for remotely sensed images. All three algorithms are applied to two panchromatic subscenes from SPOT. The performances are evaluated with the indices including entropy, correlation coefficient, root mean square error, pixel value differences, and signal noise ratio, which are computed from the differences between the compressed and the original images. The results indicate that fractal compression methods provide higher potential compression ratio. In general, when the compression ratio is larger than 50, fractal-based approaches have better performance than JPEG. Regarding feature analysis, edges of large and homogeneous areas can be recognized easier..

關鍵字

碎形、影像壓縮

Keywords

fractal, image compression

附件檔名

華芸線上圖書館

N / A

備註說明

199709-2-3-25-35

Pages:

37-76

論文名稱

遙測資訊在生態環境變遷監測上應用之研究一以台南地區為例

Title

Study on the Change Detection of Ecological Environment by Using the Remotely Sensed Data-An IIIustration of Tainan District

作者

林金樹 , 焦國模

Author

Chinsu Lin , Kuo-Mu Chiao

中文摘要

本文利用大地衛星多譜資料,檢測台南地區土地利用型景觀組類的全區分類準確度可達 80%,顯示應用遙測多譜資訊檢測大面積生態景觀組類資訊具有相當的潛在優勢。都會區與非都會區的景觀發展型態差異很大,利用遙測資訊檢測其變遷發展時,應將都會區獨立分析,以避免資訊混淆的結果。在林區的應用上,遙測多譜資料可以準確檢測出早期林木被覆區被開發的資訊,其對林木區、墾殖區以及裸地區三種土地利用型主題組類的分類可達 80% 的全區分類準確度,且對林木組類面積率變遷發展的預測準確度可達 95% 。林分鬱閉度的全區分類準確度可達 65%,由兩個時期的林分鬱閉度主題組類檢測的變遷準確度,約為該兩個影像分類準確度的乘積,有誤差相乘的擴大效應;但若以林分鬱閉度成長資訊為變遷準確度的檢測標準時,則無誤差相乘的擴大效應問題。林分鬱閉度變遷發展的動態平衡出現時期,多譜資料檢測的結果與資源調查資料預測的結果是一致的。 人口、各級產業人口、產業結構比以及道路密度等社經因子與都會區及非都會區的土地利用組類面積率有極顯著的結構關係,該等變數所建立的脊迴歸模式對景觀組類面積率變異量的解釋能力均在 90% 以上,模式預測效率及穩定性均很高。顯示利用社經因子等變數所建立的景觀組類發展模式,極適合於預測未來的組類發展資訊。

Abstract

The overall classification accuracy of both Landsat MSS and TM imagery data were more than 80 percent in this study. These results are acceptable for a large landscape area. It also showed that remote sensing techniques has an important potential value in landscape change monitoring. Since the landscape development type of urban and rural area is very different, they should be analyzed separately to extract a reasonable and correct information. The overall accuracy of the classification of tree-cover area and cultivated land and bared land is about 80 percent, and the predicted tree-cover area is very accurate with 95 percent accuracy. The detected accuracy of crown density is more than 65 percent. The change detection accuracy of two thematic images is almost equal to the multiplication of their overall classi-fication accuracy. It implied that an error expansion effect was existed. It is the except case for detecting the change of crown density growth. Whose accuracy was more than 71 percent. The beginning time of ecological dynamic balance of classes' development predicted by MSS detected data and surveyed data is almost same. All the predicted devel­opment trends can retain the real cases. The social-economic variables, inverse population density, industrial structure ratio, and road density, have a very significant and strong cause-effect relationship on the land­scape developments. All regression models developed by these factors can explain more than 90 percent variance of area percentage of every landscape class. The predicted effi­ciencies of these ridge regression models were very stable and could retain on the level of models. This encourages us to combine the multispectral scanning imagery data and ridge regression models to monitoring and predicting the landscape developments in the future.

關鍵字

遙測、環境變遷監測、土地利用、林分鬱閉度、脊迴歸分析

Keywords

Remote sensing, environment change detection, land use, crown density, ridge regression analysis.

附件檔名

華芸線上圖書館

N / A

備註說明

199709-2-3-37-76

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