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dc.contributor.authorAbuelgasim, Abdelgadir A. M.en_US
dc.date.accessioned2017-06-20T19:22:20Z
dc.date.available2017-06-20T19:22:20Z
dc.date.issued1986
dc.date.submitted1986
dc.identifier.urihttps://hdl.handle.net/2144/22548
dc.descriptionThesis (M.A.)--Boston Universityen_US
dc.description.abstractThe primary objective of this research is to test and validate a geometric-optical bidirectional reflectance canopy model developed by Li and Strahler, with respect to actual forest canopy reflectance measurments. This model treats forest canopies as scenes of discrete, three dimensional objects that are illuminated and viewed from different positions in the hemisphere. The shapes of the objects, their count densities and patterns of placement are the driving variables, and they condition the mixture of sunlit and shaded objects and background that is observed from a particular viewing direction, given a direction of illumination. This mixture, in turn, controls the brightness apparent to an observer or a radiometric instrument. The Advanced Solid-State Array Spectroradiometer (ASAS) is chosen to be the sensor having the ability of collecting measurements at various look angles and its imaged reflectance was used to validate the model. The modelled BRF's were compared to actual ASAS measured BRF's in sites with different canopy structures and densities. The comparision revealed execellent match between the modelled and measured reflectance, and great ability of the model in predicting the shape and magnitude of the BRDF, in almost all the sites investigated. It is concluded that the geometric optics approach provided a good way to model the bidirectional reflectance distribution function of natural vegetation canopies, that captures the most important features exhibited by bidirectional measurements of such canopies. Further modifications have been suggested that will improve the predicted BRF's, and yield better results. [TRUNCATED]en_US
dc.language.isoen_US
dc.publisherBoston Universityen_US
dc.rightsThis thesis is being made available in OpenBU by permission of its author, and is available for research purposes only. All rights are reserved to the author.en_US
dc.subjectOregonen_US
dc.subjectConifer forestsen_US
dc.subjectAdvanced Solid-state Array Spectroradiometeren_US
dc.titleModelling bidirectional radiance measurements collected by the advanced solid-state array spectroradiometer over Oregon transect conifer forestsen_US
dc.typeThesis/Dissertationen_US
etd.degree.nameMaster of Artsen_US
etd.degree.levelmastersen_US
etd.degree.disciplineGeographyen_US
etd.degree.grantorBoston Universityen_US


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