Sensor system for acquisition of vegetation indexes

Thales M De A Silva,Francisco De A De C Pinto,Daniel M De Queiroz,Domingos S M Valente,Nerilson T Santos

doi:10.1590/1807-1929/agriambi.v25n4p264-269

Thales M De A Silva, Francisco De A De C Pinto + Show 3 more

Open Access

https://doi.org/10.1590/1807-1929/agriambi.v25n4p264-269

Copy DOI

Abstract

ABSTRACT Vegetation indexes are important indicators of the health and yield of agricultural crops. Among the sensors used to evaluate vegetation indexes, proximal sensors can be used for real-time decision-making. Thus, the objective of this study was to develop a proximal sensor system based on phototransistors to acquire and store the following vegetation indexes: normalized difference vegetation index, simple ratio, wide dynamic range vegetation index, soil-adjusted vegetation index, and optimized soil-adjusted vegetation index. The sensor system was developed using an analog circuit to acquire reflectance data from red and near-infrared bands. The sensor system was calibrated according to the results of a spectroradiometer, using Zoysia japonica grass as the target. An algorithm that calculates and stores vegetation indexes in a file was developed. The Pearson correlation between the vegetation indexes obtained with the sensor system and the spectroradiometer was evaluated. The vegetation indexes presented a Pearson correlation higher than 0.92 to the estimated values by the spectroradiometer. Under the evaluation conditions, the proposed sensor system could be used to determine all vegetation indexes evaluated.

Highlights

Vegetation indexes are important indicators of biomass (Yue et al, 2019), soil parameters (Bernardi et al, 2017), plant chlorophyll content (Xu et al, 2019), plant cover (Shao et al, 2016), and plant leaf area (Ricci et al, 2019)
The objective of this study was to develop a proximal sensor system based on phototransistors to acquire and store the following vegetation indexes: normalized difference vegetation index, simple ratio, wide dynamic range vegetation index, soil-adjusted vegetation index, and optimized soil-adjusted vegetation index
The objective of this study was to develop a proximal sensor system based on phototransistors that operate in the red and near-infrared ranges to acquire and store the following vegetation indexes: normalized difference vegetation index (NDVI), simple ratio (SR), wide dynamic range vegetation index (WDRVI), soiladjusted vegetation index (SAVI), and optimized soil-adjusted vegetation index (OSAVI)

Summary

Introduction

Vegetation indexes are important indicators of biomass (Yue et al, 2019), soil parameters (Bernardi et al, 2017), plant chlorophyll content (Xu et al, 2019), plant cover (Shao et al, 2016), and plant leaf area (Ricci et al, 2019). Vegetation indexes can be calculated using images acquired from orbital (Zhang & Roy, 2016; Mengue et al, 2019) and suborbital (Ghazal et al, 2015; Zheng et al, 2016) platforms such as remotely piloted aircrafts. Some remotely piloted aircraft may present high cost and low flight autonomy Both approaches require the processing of images after collection (Matese et al, 2015)

Objectives

Methods

Results