Plant canopy analyzer（Image analysis）

I. Product Overview

The HD-G30 plant canopy image analyser extracts canopy gap fractions at multiple angles by various image processing methods. A camera fitted with a fisheye lens photographs the canopy upwards from below the crown, and canopy parameters are retrieved from the gap fraction parameters. The instrument provides a reliable scientific basis for rational fertilisation in orchards and for efficient management of modern farms, and is widely used in scientific research and production guidance in agriculture, forestry and plant science.

II. Measuring Principle and Method

The plant canopy image analyser is based on the relationship between canopy porosity and canopy structure. Following the Beer–Lambert law of light attenuation through a medium, and under a series of defined assumptions about the plant canopy, canopy structure parameters are calculated from measured canopy porosity using semi-theoretical, semi-empirical formulae. This principle is used by canopy instruments throughout the world. On this basis, the analyser measures canopy porosity by analysing hemispherical sky images taken beneath the canopy, which is the most accurate, the least labour-intensive, the fastest and the most convenient of all available methods.

III. System Composition

The analyser consists of a fisheye image capture probe (a fisheye lens with a CMOS image sensor), a measuring rod (swing arm) with 25 built-in PAR sensors, a notebook computer and image analysis software. The fisheye probe is mounted at the tip of a very light swing arm and acquires fisheye images with a 180° field of view. Images are displayed and stored on the supplied notebook computer.

IV. Technical Parameters

V. Key Features

1. The fisheye lens keeps itself horizontal automatically: the compact fisheye camera designed specifically for plant canopy structure measurement is mounted on a handheld universal balance joint, which keeps the lens horizontal without a tripod.

2. The fisheye lens can reach into the canopy: because the lens is compact and mounted at one end of the swing arm with the measuring rod, it can easily be extended horizontally forwards or vertically upwards to different heights within the canopy for rapid stratified measurement, giving the light transmittance within the stand and the vertical distribution of the leaf area index.

3. Image analysis software: the analysis area can be defined freely (the zenith angle can be divided into 10 zones and the azimuth angle into 10 zones).

4. Unreasonable canopy portions can be masked: when analysing different canopy directions region by region, ground features and unreasonable canopy portions (such as missing plants or edge rows) can be masked at will.

5. Automatic threshold adjustment, avoiding the increased error caused by subjective threshold settings.

6. Equipped with a Beidou satellite positioning module that displays longitude and latitude in real time to identify the current measuring position.

7. Results can be transmitted directly to a dedicated cloud agricultural data centre; a dedicated account is provided.

8. Data browsing: historical data can be viewed.

9. Built-in bilingual Chinese/English display with one-key switching.

10. Batch detection and batch export.

11. The software is compatible with Windows 10 and above only.