Geometric-optics forest canopy modelling for high spatial resolution imagery
- Canada Centre for Remote Sensing, Ottawa, Ontario (Canada)
This research studies processes influencing the radiometric appearance of a forest at fine spatial resolution. A canopy radiance model, Treatment of Radiance Emerging from Light Interactions in a Treed Environment (TRELITE), was formulated using a geometric-optical approach. This model explored the relationship between image radiometric textures and canopy physical parameters. TRELITE`s geometric parameters of influence were tree shape, pixel dimension, source and viewing directions, and forest configuration. TRELITE`s optical parameters and interaction processes were collimated and sky irradiance, surface reflectivity, object transmissivity, and projected and mutual shading. Simulated airborne images were generated from a physical representation of these parameters. Four conifer plantation test sites were chosen to evaluate the influence of the modelled parameters on the scene radiance. The Multispectral Electro-Optical Imaging Scanner (MEIS-II), with 45 cm spatial resolution for eight channels spanning visible to near-infrared, measured scene radiance. MEIS image radiance patterns were analyzed for single trees, in four monospecific stands. The influence on the simulated radiance of the modelled canopy factors in TRELITE were examined, on a single tree basis, to determine relative importance in high spatial resolution imagery. Several modelling options were tested. Among them, the most appropriate tree outline shape was the truncated ellipse. Details of simulated images, particularly those in shaded areas, compared more favorably with airborne images when both collimated and diffuse illumination were modelled. Three processes emerged which were imperative to successful simulation: mutual shading (on-object and between object), bidirectional reflectance, and light transmissivity through crowns. 9 refs., 2 figs., 2 tabs.
- OSTI ID:
- 390736
- Report Number(s):
- CONF-960613-; TRN: 96:004292-0041
- Resource Relation:
- Conference: 2. international airborne remote sensing conference and exhibition, San Francisco, CA (United States), 24-27 Jun 1996; Other Information: PBD: 1996; Related Information: Is Part Of Proceedings of the second international airborne remote sensing conference and exhibition: Technology, measurement & analysis. Volume III; PB: 870 p.
- Country of Publication:
- United States
- Language:
- English
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