Abstract
We apply the principles of atmospheric surface layer dynamics within a vineyard canopy to demonstrate the use of forward-looking infrared cameras measuring surface brightness temperature (spectrum bandwidth of 7.5 to 14 μm) at a relatively high temporal rate of 10 s. The temporal surface brightness signal over a few hours of the stable nighttime boundary layer, intermittently interrupted by periods of turbulent heat flux surges, was shown to be related to the observed meteorological measurements by an in situ eddy-covariance system, and reflected the above-canopy wind variability. The infrared raster images were collected and the resultant self-organized spatial cluster provided the meteorological context when compared to in situ data. The spatial brightness temperature pattern was explained in terms of the presence or absence of nighttime cloud cover and down-welling of long-wave radiation and the canopy turbulent heat flux. Time sequential thermography as demonstrated in this research provides positive evidence behind the application of thermal infrared cameras in the domain of micrometeorology, and to enhance our spatial understanding of turbulent eddy interactions with the surface.
Highlights
There is great interest in using near-target remote sensing techniques such as time-sequential thermography (TST) in precision agriculture, ecology [1] and phenomics [2]
We have demonstrated the use of forward-looking infrared cameras measuring the surface brightness temperature over a vineyard in the spectrum bandwidth of 7.5 to 14 μm at a relatively high temporal rate of 10 s for the application of vineyard-scale micrometeorology
Our results show that this technique, when applied for interpreting the micrometeorology as a function of cloud cover and within-canopy turbulence, could become a useful tool for up-scaling point measurements to spatially wide footprints
Summary
There is great interest in using near-target remote sensing techniques such as time-sequential thermography (TST) in precision agriculture, ecology [1] and phenomics [2]. Plants are more than passive objects and employ stomata to sense the surrounding environment and respond rapidly to abiotic stresses, such as the air temperature. Their response is typically through stomatal conductance to water vapor and/or transpiration, which are critical physiological controls. To understand the plant’s microclimate through thermography (or the environment that embodies the plant to a few orders of magnitude in spatial scale relative to the plant’s volume), it is important to understand the brightness temperature signal (measured by a infrared camera) as a function of near-surface meteorological parameters controlling the energy exchanges happening across the plant-environment envelope
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
