Development of a hyperspectral imaging system for plant health monitoring in space crop production

Abstract

This paper presents development of an automated hyperspectral system to monitor plant health for produce production in NASA’s space missions. The system was designed to inspect salad crops using both reflectance and fluorescence imaging in a spectral region of 400–1000 nm. Major hardware components of the system include a compact line-scan hyperspectral camera, two LED line lights providing broadband and UV-A light for reflectance and fluorescence measurement, and a linear translation stage. In a sensor-to-sample arrangement, the translation stage moves the camera and the lights over the plants to acquire a pair of matched reflectance and fluorescence images in a line-scan imaging cycle. Control software was developed using LabVIEW to realize hardware parameterization and data transfer functions. The imaging system was installed in a growth chamber at NASA Kennedy Space Center for plant health monitoring studies. A demonstration experiment was conducted to detect drought stress for Dragoon lettuce. Two‐band reflectance ratio images at 690 and 702 nm were able to detect the drought stress on lettuce leaves without visible symptoms.