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題名 | 評估臺灣常綠闊葉森林之衛星影像植生指標與空載光達穿透率之相關性=Assessment of the Relationship between Satellite-Derived Vegetation Index and Lidar-Based Laser Penetration Index in Evergreen Broadleaf Forest |
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作者 | 李崇誠; 王驥魁; 洪子敏; 吳坤真; | 書刊名 | 航測及遙測學刊 |
卷期 | 20:4 2016.06[民105.06] |
頁次 | 頁251-262 |
分類號 | 440.98 |
關鍵詞 | 空載光達; 森林穿透率; 大氣糾正; 衛星影像植生指標; Airborne LiDAR; Laser penetration index of forest; Atmospheric correction; Satellite-derived vegetation index; |
語文 | 中文(Chinese) |
中文摘要 | 由於空載光達系統其雷射光會穿透森林樹冠層到達地表,植生的密度會影響到穿透率程度之大小,而穿透率的推估方式為統計雷射光穿透森林冠層到達地面之比率,故穿透率越高所獲得的地面點相對增 加,對於DEM產製有高度的影響,然穿透率屬於執行飛航任務事後獲得的資訊,本研究目的探討衛星影像植生指標與空載光達穿透率之關係,主要目的為提供光達掃瞄規劃之參考,在森林植生覆蓋度高的區域,可以增加入射森林之雷射光能量的方式來提升穿透率。本研究總共測試台灣南北兩個光達樣區,分別為北部金山的火山樣區與南部曾文水庫樣區,掃瞄面積分別為36km2與21km2,並取得Fomosat-2、SPOT-5、Worldview-2與GeoEye共7幅衛星影像,分別計算4種植生指標(NDVI、RVI、PVI與SAVI),拍攝時間與空載光達掃瞄時間相近,結果顯示衛星影像需經過大氣糾正處理消除水氣和地形之影響因子, 並以Pearson相關性檢定其植生指標與穿透率之相關,結果為兩指數有顯著負相關性,表示當穿透率越高時植生指標相對減少,並以線性回歸探討兩者之關係,其R2值均高於0.8以上,代表衛星影像植生指標與空載光達穿透率有程度上之相關。 |
英文摘要 | The forest canopy affects the laser penetration rate of airborne LiDAR system (ALS). The denser the forest canopy, the higher the laser penetration rate, and vice versa. For an ALS survey project, with the goal to acquire sufficient ground surface points, the flight planning should be conducted according to the distribution forest canopy thickness. The information of forest canopy can be easily accessed via the satellite-derived vegetation index. In this study, we examined the correction relationship between the satellite-derived vegetation index and laser penetration index (LPI). The study area was 21 km2 located in Tseng-Wen Reservoir and 36 km2 located in Jin-Shan volcanic region. The ALS data were collected with an Optech HD400 instrument. The LPI is the ratio between the total number of laser pulses reaching at the ground surface and the total number of transmitted laser pulses. The vegetation indices were calculated from Formsat-2, SPOT-5, WorldView2 and GeoEye, all of which were acquired near the time of ALS data acquisition. This study calculated four vegetation indices, i.e., NDVI, RVI, PVI, and SAVI. The effect of atmospheric correction (conducted by ATCOR-3) were also discussed. The results show high linear correlation between LPI and LAI. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。