نتایج جستجو برای: canopy angle
تعداد نتایج: 144935 فیلتر نتایج به سال:
Generating accurate and unbiased wall-to-wall canopy height maps from airborne lidar data for large regions is useful to forest scientists and natural resource managers. However, mapping large areas often involves using lidar data from different projects, with varying acquisition parameters. In this work, we address the important question of whether one can accurately model canopy heights over ...
Coniferous tree canopies typically carry more leaf area than is necessary to intercept most of the incoming light. I postulated that an excessively large leaf area will reduce net productivity at tree level, unless the net photosynthetic production of the most shaded shoots in the canopy remains positive. The hypothesis tested was that a coniferous tree canopy maintains a large productive leaf ...
Radar backscatter from forest canopies is related to forest cover, canopy structure and aboveground biomass (AGB). The S-band frequency (3.1–3.3 GHz) lies between the longer L-band (1–2 GHz) and the shorter C-band (5–6 GHz) and has been insufficiently studied for forest applications due to limited data availability. In anticipation of the British built NovaSAR-S satellite mission, this study ev...
Both Imaging Spectrometry and LIDAR have been already investigated as independent data sources to describe and quantify forests properties. While Imaging Spectrometry provides information on the biochemical and biophysical properties of the canopy, LIDAR resolves the spatial and vertical distribution of the canopy structure (1, 2). The presented contribution outlines a concept how these two com...
Light models for vegetation canopies based on the turbid medium analogy are usually limited by the basic assumption of random foliage dispersion in the canopy space. The objective of this paper was to assess the effect of three possible sources of non-randomness in tree canopies on light interception properties. For this purpose, four threedimensional (3-D) digitized trees and four theoretical ...
Efficient utilization is a pre-requisite for pesticide reduction, and appropriate airflow distribution pattern plays key role in enhancing the effectiveness of application by air-assisted orchard sprayers, yet mechanism this unclear. In order to clarify specific effects velocity direction on spraying efficacy, series spray tests pear cherry open areas were conducted multi-unit sprayer ten diffe...
Multi-angle remote sensing can either be regarded as an added source of uncertainty for variable retrieval, or as a source of additional information, which enhances variable retrieval compared to traditional single-angle observation. However, the magnitude of these angular and band effects for forest structure parameters is difficult to quantify. We used the Discrete Anisotropic Radiative Trans...
The ‘ellipsoidal distribution’, in which angles are assumed to be distributed parallel to the surface of an oblate or prolate ellipsoid, has been widely used to describe the leaf angle distribution (LAD) of plant canopies. This ellipsoidal function is constrained to show a probability density of zero at an inclination angle of zero; however, actual LADs commonly show a peak probability density ...
Physical and functional properties of foliage were measured at a variety of microsites in a broad-leaved Nothofagus fusca (Hook. f.) Ørst. canopy. The light climate of the foliage at these sites was monitored for 39 days in the late spring and early summer with in situ sensors. Foliage nitrogen content (N), mean leaf angle, and gas exchange characteristics were all correlated with the amount of...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید