Study of Fruiter LAI Realtime Measurement System

Leaf area index (LAI) is a critical structural parameter in evaluating physiology and biology of vegetation canopy and ecosystem, which makes its quick and precise measurement necessary though still unrealized owing to the different LAI definitions, diverse suggestions and measurement variance. And virtual plant, virtual reality and virtual instruments (VI) provide new tools in agricultural measurement based on increasing development of computer technology. By integrating virtual plants, virtual reality and virtual instrument technologies, a fruiter LAI realtime measurement system was established to test LAI of real Litchi and LAI of manmade Litchi made with 3D digitalizer base on the real one. One the one hand, LAI system compiles OpenGL and VC++ with LabVIEW for computer model simulating, and on the other hand, system analyzes, saves and displays data such as PAR, temperatures, and sensor position, then calculates the LAI and output motor control order to realize the sensor movement. Hereinto, a kind of useful random distribution arithmetic was created and distributed leaves were visualized and shadowed. Additionally, LAI arithmetic for Litchi was test for optimal sampling parameters. After calibration and comparison, the LAI system is satisfied to our project requirement.