ENGLISH

5卷/1期

5卷/1期

華藝線上圖書館

Pages:

1-14

論文名稱

類神經網路於多光譜影像分類之應用

Title

The Application of Neural Network for the Image Classification of Multispectral Data

作者

邵泰璋 , 史天元

Author

Tai-Chang Shao , Tian-Yuan Shin

中文摘要

台灣省糧食局每年採用航照遙測技術調查稻作,並以人工辨識航照方法,估算水稻田面積與產量。若發展適當的客觀分類辨識方法,將可減少時間、人力與物力之投入,且避免人為判釋上的主觀差異。 本研究採用類神經網路,其模仿人類神經元記憶思考的處理模式與容錯性的特點,適合分類工具的發展。研究中,選用監督式理論較具代表的倒傳遞類神經網路,與混合監督式與非監督式的學習向量量化類神經網路,並採用兩種不同資料編碼輸入網路模式,分別針對彰化地區多時段SPOT衛星影像與多時段正規化差分植生指數影像作水稻田分類工作。分類成果與傳統高斯最大概似法相比較,最後並加入紋理影像輔助分類。研究結果就整體而言,類神經網路確實比傳統高斯最大概似分類法為佳,尤其以倒傳遞類神經網路最為有效,學習向量量化類神經網路次之。

Abstract

Taiwan Provincial Food Department utilizes aerial photo interpretation for rice crop inventory each year to calculate the areas. If an automated classification method can be developed, the amount of time, manpower, and resources needed in the current work can be reduced. Meanwhile, the errors caused by human subjective interpretation can be avoided. This research uses artificial neural network, which simulates human neuron and fault-tolerance for classification. In this study, error back-propagation (BP) and learning vector quantization (LVQ) neural network algorithms are selected. Meanwhile, two data coding techniques are applied for data representation to input network model. The data used in the experiment are multi-temporal SPOT images and multi-temporal NDVI images of Changhua area. All the classification results are com- pared with those produced by Gaussian maximum likelihood algorithm. Finally, the contribution of texture images for classification are studied. In general, the experiments reveal that neural network approaches are better than maximum likelihood classification. Especially BP, and LVQ is thesecond­best.

關鍵字

遙感探測、類神經網路、影像分類

Keywords

Remote Sensing, Neural Network, Image Classification

附件檔名

華芸線上圖書館

N / A

備註說明

200003-5-1-1-14

Pages:

17-31

論文名稱

應用數位航測技術於三義火炎山地形變遷之研究

Title

A Study on the Geomorphological Change in Hoyenshan Nature Reserve

作者

陳永寬 , 葉堃生 , 詹進發

Author

Yeong. Kuan Chen , Kuen. Sheng Yeh , Jihn. Fa Jan

中文摘要

本研究以三義火炎山自然保留區為試驗區,利用四期航空照片為材料, (1) 以全球衛星定位系統測量地面控制點; (2) 以數位航空測量技術蒐集地形特徵資料點; (3) 以影像自動匹配技術自動化生產各期規整網格數值地形模型。然後,分析比對此等數值地形模型,計算土壤沖蝕量與地形變化量,探討歷年地形地貌變遷。 應用影像自動匹配技術生產DTM資料,直接受到照片品質與重疊率之影響。為提高匹配成功率與正確度,如於匹配失敗區及地形特殊區,以人工作業加測地形斷線,取代原自動匹配高程,構造新TIN,再進行內插產生規整高程點,則較理想。 森林覆蓋區,自動匹配所獲得者為數值覆蓋面模型。用以萃取水系分佈與集水區邊界以探討邊坡後退的變化情形則可;如用於土方變化分析時,則須事先排除林木覆蓋區域,以免土方計算受到林木生長的影響。 本研究結果顯示,影響火炎山地形變化之因素眾多,頻度、強度、地點不定,難以計算出單一變化模式。若僅欲了解地形地貌變遷之表象,則使用多期航空照片,以數位航測技術配合適度人工斷線測量,自動化生產數值地形模型分析之,應不失為安全、省時、省事之方法。

Abstract

In this research, the Hoyenshan Nature Reserve at Sanyi was selected as the study site. This research utilized aerial photos obtained in four different years to investigate the soil erosion in the study area. Specific procedures of the research include: (1) to obtain coordinates of ground control points applying GPS surveying; (2) to collect data of topographic features using digital photo-grammetry; (3) to establish DTMs applying automatic matching techniques. Finally, by analyzing those DTMs, we quantify the soil erosion and establish a model for evaluating the geomorphological change within the study area. When applying automatic matching technique in collecting DTM points the quality and percentage of overlap of the aerial photos usually affect the results. To obtain better results, manual digitization of break lines is required for those areas that have poor results in previous runs, then the interpolation is performed to generate regular DTM points. Automatic matching is based on the gray values of digital images therefore, digital surface model (DSM) is obtained through the process. The results indicate that DSM can be used to derive drainage system and watersheds, the geomorphological change can then be e valuated by com­paring the drainage systems and watersheds of different years. To estimate the volume of soil loss, however, the areas covered by forest should be excluded so that the computed volume is not affected by the tree growth. The geomorphological change of the study area is affected by many factors. More-over, the fre­quency, intensity, and locations are varying. Therefore, it is very difficult to model the geomor­phological change. However, based on the volume and rate of soil loss, it is estimated that the unique geomorphologic features of the study area should still remain for a long period of time.

關鍵字

地形地貌變遷、數位航測、數值地形模型、影像自動匹配、土方分析

Keywords

geomorphological change, digital photogrammetry, digital terrain model, automatic image matching, soil volume analysis

附件檔名

華芸線上圖書館

N / A

備註說明

200003-5-1-17-31

Pages:

33-53

論文名稱

應用GPS載波相位餘弦模式於衛星測量之研究

Title

Research On The Application Of GPS Carrierphase Cosine Functions To Satellite Surveying

作者

游豐吉

Author

Fong-Gee Yiu

中文摘要

欲進行高精度GPS衛星定位,必須處理載波相位觀測量,有兩種法則可資應用:一為相位模稜參數求定,另一則以三角函數將整數模稜參數消去。本文由相位模稜消去方面入手,探討相位餘弦模式。除比較此法與相位模稜搜尋之異同,並詳細討論相位餘弦模式之理論與特性。將本模式應用於衛星高程測量,證明其精度可符合二等水準測量之規範。此外,可一併求定對流層與電離層影響量。此法可應用動態定位,其求解成果與模稜求定成果相當。最後則設計多主站之相位餘弦模式。

Abstract

For high-precision GPS satellite positioning, Carrier phase observables must be processed. There are two algorithms to. follows. One is to determine the correct phase ambiguity param­eters, the other uses the trigonometric functions to eliminate the integer ambiguity parameters. The purpose of this paper is to establish a set of model, namely cosine function models of carrier phases. This paper begins with cosine function models of carrier phases, and compares the differences between the method and phase ambiguity resolution. A detailed discussion concerning the characteristics of cosine function models of phases is offered, it can be applied to satellite leveling with proof of fulfilling the accuracy requirement of second-order class II leveling. Be- sides, this model helps us to estimate the path delays of tropospheric as well as ionospheric alto­gether. Kinematic positioning can be applied with this model with such an achievement equiva­lent to that of ambiguity resolution. The last part of this paper contributes to designing the cosine function models of phases with muti-refference station.

關鍵字

相位模稜、最小二乘技術、相位餘弦模式

Keywords

Phase ambiguity, Least square technique, cosine function models of carrier phases

附件檔名

華芸線上圖書館

N / A

備註說明

200003-5-1-33-53

Pages:

55-72

論文名稱

「科技短文」利用熱紅外線輻射影像遙測技術追蹤盤固草(Digitaria decumbens Stent.)植被溫度之季節變化

Title

Monitoring Seasonal Changes in Canopy Temperature of Digitaria decumbens Stent. by Thermal Infrared Remote Sensing

作者

楊純明 , 賴小麗 , 施意敏 , 卜瑞雄

Author

Chwen-Ming Yang , Hsiao-Li Lai , Yih-Min Shy , Ruey-Hshiung Buu

中文摘要

本文研究於行政院農業委員會畜產試驗所新竹分所農場利用熱紅外線輻射影像遙測技術探討盤固草(pangolagrass, line A254)植被覆蓋溫度之季節變化,並試予評估盤固草植被輻射溫度與周遭氣溫及土壤溫度間之相關。根據試驗結果,顯示盤固草植被溫度明顯受到生長與環境效應之影響,一般言,常態狀況下盤固草植株蒸散作用之散熱功能維繫生長期間植被溫度低於周遭氣溫及土溫,惟在割刈初期因土壤背景溫度干擾導致所偵測之植被熱紅外線輻射溫度高於周遭氣溫及土溫。盤固草植被溫度之分佈端視植被覆蓋之整齊度及土壞溫度、氣溫而定,亦受到天氣影響。又晴朗天空強烈的太陽光照造成額外之反射輻射能量受測於熱紅外線輻射影像儀,形成土壤輻射溫度高估現象,因此土壤輻射溫度測值高於土壤動態溫度測值。盤固草植被生長性狀(鮮重與乾重)與植被溫度之間並無顯著正相闕,所以不宜以植被溫度作為估測生長表現之唯一參數。綜合試驗結果,顯示盤固草具有溫調機制以適應周遭環境溫度變化,並容忍較差溫度條件。

Abstract

Technique of thermal infrared imagery was applied to monitor seasonal changes in canopy temperature of pangolagrass (Digitaria decumbens Stent.) grown in the experimental field at Hsinchu branch station of Taiwan Livestock Research Institute. Fluctuation of canopy radiometric temperatures in response to ambient air temper-ature and soil surface temperature remotely measured from a portable thermal inf-rared imaging radiometer was also studied. Results indicated that seasonal changes in temperature of pangolagrass vegetative can­opy were influenced by both growth and environmental effects. Generally can­opy temperature was lower than air and soil temperatures, except in the period imm ediately after cutting where soil background effect was strong and canopy was not full covered. Temperature distribution of can­opy depended on the uni­formity of vegetative cover as well as soil temperature, air temperature, and climatic condition. The strong reflected solar radiation over soil plus the emitted longwave radiation from soil resulted in an over-estimated soil radio-metric temperature against soil dynamic temperature near noon. However, no close rel­ationship was found between growth characters (plant fresh weight and dry we­ight) and canopy temperature, yet plant weight and plant height was closely related. Re-sults suggest that the ability of temperature adjustment enables plants of pangolagrass tolerating to less favorable environmental conditions.

關鍵字

盤固草、植被覆蓋、植冠、熱紅外線影像技術、溫度季節變化、生長性狀

Keywords

Pangolagrass, Vegetative cover, Canopy, Thermal infrared imagery, Seasonal temperature change, Growth character

附件檔名

華芸線上圖書館

N / A

備註說明

200003-5-1-55-72

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