Forest stand radiation flux calculation method based on point cloud data and computer graphics

Abstract

The invention discloses a forest stand radiation flux calculation method based on point cloud data and computer graphics. The method comprises the following steps: collecting forest stand point cloud data; calculating the solar irradiance of the horizontal surface of the forest stand; segmenting a single tree crown; simulating a broad-leaved crown by using the spatial semi-ellipsoid geometric primitive or / and simulating a coniferous crown by using the spatial cone geometric primitive; triangulation is carried out on the tree crown after geometric primitive simulation; determining a first intersection point of the incident solar beam and the triangle, and calculating the incident radiation flux of the forest stand; calculating reflection radiation flux among trees in the forest stand; and calculating the transmission radiation flux of the forest stand. According to the method, by determining emission and collision of solar beams and quantifiable energy in a plurality of spatial triangles covering the surface of a forest canopy, complications related to sunlight shielding caused by organ scale heterogeneity in fine representation of tree organs and plant systems are overcome.

Description

technical field [0001] The invention relates to the technical field of stand radiation flux research, in particular to a stand radiation flux calculation method based on point cloud data and computer graphics. Background technique [0002] Solar radiation is an important source of energy for physiological processes such as photosynthesis and transpiration in plants. The solar radiation received by the plant canopy is dynamic and is affected not only by the intensity and direction of the incident sun, but also by the structure of the canopy. The acquisition of canopy radiant flux is a frontier field of forest phenotyping research, which is of great significance for the selection and breeding of high light-efficiency tree types and for guiding forest management of productive stands. Solar radiation status also affects net primary productivity, forest species abundance, ecosystem response mechanisms and site adaptation characteristics. [0003] Prior knowledge of the local an...

AI Technical Summary

Problems solved by technology

For example, the camera needs to be absolutely level under the forest canopy, which inevitably leads to unmanageable camera misalignment problems

In addition, the results obtained within the canopy are subject to unexpected biases due to partial shading, uncertain fractional calculations due to variations in camera exposure values ​​of camera equipment parameters, and the presence of dust or water vapor in the air, introducing noise into the image

For large forest stands, the high temporal and spatial sampling resolution of forest plots coupled with statistical analysis to quantify the solar radiation received by the forest reduces the generalizability of the results, and the experimental work is time-consuming and prone to unstable results

Images