Mapping vineyard leaf area using mobile terrestrial laser scanners: should rows be scanned on-the-go or discontinuosly sampled?

The leaf area index (LAI) is defined as the one-side leaf area per unit ground area, and is probably the most widely used index to characterize grapevine vigor. However, LAI varies spatially within vineyard plots. Mapping and quantifying this variability is very important for improving management de...

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Bibliographic Details
Authors: Moral Martínez, Ignacio del, Rosell Polo, Joan Ramon, Company Mesa, Joaquim, Sanz Cortiella, Ricardo, Escolà i Agustí, Alexandre, Masip Vilalta, Joan, Martínez Casasnovas, José Antonio, Arnó Satorra, Jaume
Format: article
Status:Published version
Publication Date:2016
Country:España
Institution:Universitat de Lleida (UdL)
Repository:Repositori Obert UdL
OAI Identifier:oai:repositori.udl.cat:10459.1/49390
Online Access:https://doi.org/10.3390/s16010119
http://hdl.handle.net/10459.1/49390
Access Level:Open access
Keyword:lidar
LAI
Mobile terrestrial laser scanner
precision viticulture
vegetation maps
Viticultura
Cartografia de la vegetació
Viticulture
Vegetation mapping
Description
Summary:The leaf area index (LAI) is defined as the one-side leaf area per unit ground area, and is probably the most widely used index to characterize grapevine vigor. However, LAI varies spatially within vineyard plots. Mapping and quantifying this variability is very important for improving management decisions and agricultural practices. In this study, a mobile terrestrial laser scanner (MTLS) was used to map the LAI of a vineyard, and then to examine how different scanning methods (on-the-go or discontinuous systematic sampling) may affect the reliability of the resulting raster maps. The use of the MTLS allows calculating the enveloping vegetative area of the canopy, which is the sum of the leaf wall areas for both sides of the row (excluding gaps) and the projected upper area. Obtaining the enveloping areas requires scanning from both sides one meter length section along the row at each systematic sampling point. By converting the enveloping areas into LAI values, a raster map of the latter can be obtained by spatial interpolation (kriging). However, the user can opt for scanning on-the-go in a continuous way and compute 1-m LAI values along the rows, or instead, perform the scanning at discontinuous systematic sampling within the plot. An analysis of correlation between maps indicated that MTLS can be used discontinuously in specific sampling sections separated by up to 15 m along the rows. This capability significantly reduces the amount of data to be acquired at field level, the data storage capacity and the processing power of computers.