کد مقاله کد نشریه سال انتشار مقاله انگلیسی ترجمه فارسی نسخه تمام متن
4464639 1313839 2016 9 صفحه PDF ندارد دانلود رایگان
عنوان انگلیسی مقاله
Estimation of canopy attributes in beech forests using true colour digital images from a small fixed-wing UAV
ترجمه فارسی عنوان
برآورد ویژگی های اریب در جنگل های راش با استفاده از تصاویر دیجیتال رنگی واقعی از یک پهپاد کوچک با بال ثابت
کلمات کلیدی
هواپیماهای بدون سرنشین؛ eBee Sensefly؛ شاخص سطح برگ؛ پوشش عکاسی؛ عکاسی نیم کروی؛ sylvatica راش
Drone; Sensefly eBee; Leaf area index; Cover photography; Hemispherical photography; Fagus sylvatica
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات کامپیوتر در علوم زمین
چکیده انگلیسی


• Forest canopy estimates were obtained using a small UAV and a commercial RGB camera.
• True colour UAV images accurately quantified canopy cover.
• Leaf area index from UAV is influenced by leaf angle distribution assumption.

Accurate estimates of forest canopy are essential for the characterization of forest ecosystems. Remotely-sensed techniques provide a unique way to obtain estimates over spatially extensive areas, but their application is limited by the spectral and temporal resolution available from these systems, which is often not suited to meet regional or local objectives. The use of unmanned aerial vehicles (UAV) as remote sensing platforms has recently gained increasing attention, but their applications in forestry are still at an experimental stage. In this study we described a methodology to obtain rapid and reliable estimates of forest canopy from a small UAV equipped with a commercial RGB camera. The red, green and blue digital numbers were converted to the green leaf algorithm (GLA) and to the CIE L*a*b* colour space to obtain estimates of canopy cover, foliage clumping and leaf area index (L) from aerial images. Canopy attributes were compared with in situ estimates obtained from two digital canopy photographic techniques (cover and fisheye photography).The method was tested in beech forests. UAV images accurately quantified canopy cover even in very dense stand conditions, despite a tendency to not detecting small within-crown gaps in aerial images, leading to a measurement of a quantity much closer to crown cover estimated from in situ cover photography. Estimates of L from UAV images significantly agreed with that obtained from fisheye images, but the accuracy of UAV estimates is influenced by the appropriate assumption of leaf angle distribution.We concluded that true colour UAV images can be effectively used to obtain rapid, cheap and meaningful estimates of forest canopy attributes at medium-large scales. UAV can combine the advantage of high resolution imagery with quick turnaround series, being therefore suitable for routine forest stand monitoring and real-time applications.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Applied Earth Observation and Geoinformation - Volume 47, May 2016, Pages 60–68
نویسندگان
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