Table 2.

Summary of calibration and validation experiments for the RGB-D, thermal, and hyperspectral cameras used in the GPhenoVision system.

Sensor	Test parameter	Test location	Test objective
RGB-D camera	Depth accuracy	Field	Validate the accuracy of sensor measurements of morphological traits
Thermal camera	Measurement accuracy (compared with thermocouple measurements) for an object with various temperatures	Laboratory	Validate the measurement accuracy in a control environment to provide an accuracy baseline
Thermal camera	Measurement accuracy (compared with thermocouple measurements) for an object at different distance to the camera	Field	Validate the repeatability of measurements due to the change of object-to-camera distance
Thermal camera	Temperature differences between thermal camera measurements for plants under shaded and unshaded areas	Field	Verify the absence of the shading effect to canopy temperature measurements
Hyperspectral camera	Accuracy of the regression model between pixel locations on the spectral dimension and standard wavelengths	Laboratory	Calibrate and validate the relationship between pixel locations on the spectral dimension and wavelengths in a scan line
Hyperspectral camera	Maximum and minimum spatial resolution	Field	Calibrate and validate the spatial resolution of the camera under various object-to-camera distances