Towards an Improved LAI Collection Protocol via Simulated and Field-Based PAR Sensing
AbstractIn support of NASA’s next-generation spectrometer—the Hyperspectral Infrared Imager (HyspIRI)—we are working towards assessing sub-pixel vegetation structure from imaging spectroscopy data. Of particular interest is Leaf Area Index (LAI), which is an informative, yet notoriously challenging parameter to efficiently measure in situ. While photosynthetically-active radiation (PAR) sensors have been validated for measuring crop LAI, there is limited literature on the efficacy of PAR-based LAI measurement in the forest environment. This study (i) validates PAR-based LAI measurement in forest environments, and (ii) proposes a suitable collection protocol, which balances efficiency with measurement variation, e.g., due to sun flecks and various-sized canopy gaps. A synthetic PAR sensor model was developed in the Digital Imaging and Remote Sensing Image Generation (DIRSIG) model and used to validate LAI measurement based on first-principles and explicitly-known leaf geometry. Simulated collection parameters were adjusted to empirically identify optimal collection protocols. These collection protocols were then validated in the field by correlating PAR-based LAI measurement to the normalized difference vegetation index (NDVI) extracted from the “classic” Airborne Visible Infrared Imaging Spectrometer (AVIRIS-C) data (
Share & Cite This Article
Yao, W.; Kelbe, D.; Leeuwen, M.V.; Romanczyk, P.; Aardt, J.V. Towards an Improved LAI Collection Protocol via Simulated and Field-Based PAR Sensing. Sensors 2016, 16, 1092.
Yao W, Kelbe D, Leeuwen MV, Romanczyk P, Aardt JV. Towards an Improved LAI Collection Protocol via Simulated and Field-Based PAR Sensing. Sensors. 2016; 16(7):1092.Chicago/Turabian Style
Yao, Wei; Kelbe, David; Leeuwen, Martin V.; Romanczyk, Paul; Aardt, Jan V. 2016. "Towards an Improved LAI Collection Protocol via Simulated and Field-Based PAR Sensing." Sensors 16, no. 7: 1092.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.