Search results for " NDVI"

High-resolution UAV imagery for field olive (Olea europaea L.) phenotyping

2021

Remote sensing techniques based on images acquired from unmanned aerial vehicles (UAVs) could represent an effective tool to speed up the data acquisition process in phenotyping trials and, consequently, to reduce the time and cost of the field work. In this study, we assessed the ability of a UAV equipped with RGB-NIR cameras in highlighting differences in geometrical and spectral canopy characteristics between eight olive cultivars planted at different planting distances in a hedgerow olive orchard. The relationships between measured and estimated canopy height, projected canopy area and canopy volume were linear regardless of the different cultivars and planting distances (RMSE of 0.12 m…

Vegetation Types Mapping Using Multi-Temporal Landsat Images in the Google Earth Engine Platform

2021

Vegetation Types (VTs) are important managerial units, and their identification serves as essential tools for the conservation of land covers. Despite a long history of Earth observation applications to assess and monitor land covers, the quantitative detection of sparse VTs remains problematic, especially in arid and semiarid areas. This research aimed to identify appropriate multi-temporal datasets to improve the accuracy of VTs classification in a heterogeneous landscape in Central Zagros, Iran. To do so, first the Normalized Difference Vegetation Index (NDVI) temporal profile of each VT was identified in the study area for the period of 2018, 2019, and 2020. This data revealed strong se…

Automatic detection and agronomic characterization of olive groves using high-resolution imagery and LIDAR data

2014

The Common Agricultural Policy of the European Union grants subsidies for olive production. Areas of intensified olive farming will be of major importance for the increasing demand for oil production of the next decades, and countries with a high ratio of intensively and super-intensively managed olive groves will be more competitive than others, since they are able to reduce production costs. It can be estimated that about 25-40% of the Sicilian oliviculture must be defined as “marginal”. Modern olive cultivation systems, which permit the mechanization of pruning and harvest operations, are limited. Agronomists, landscape planners, policy decision-makers and other professionals have a grow…

First evaluation of the simultaneous SMOS and ELBARA-II observations in the Mediterranean region

2012

Abstract The SMOS (Soil Moisture and Ocean Salinity) mission was launched on November 2, 2009. Over the land surfaces, simultaneous retrievals of surface soil moisture (SM) and vegetation characteristics made from the multi-angular and dual polarization SMOS observations are now available from Level-2 (L2) products delivered by the European Space Agency (ESA). Therefore, first analyses evaluating the SMOS observations in terms of Brightness Temperatures (TB) and L2 products (SM and vegetation optical depth TAU) can be carried out over several calibration/validation (cal/val) sites selected by ESA over all continents. This study is based on SMOS observations and in situ measurements carried …

Exploring the use of Unmanned Aerial Vehicles (UAVs) with the simplified ‘triangle’ technique for soil water content and evaporative fraction retriev…

2020

Participation of Dr. Petropoulos has been funded by the ENViSIoN-EO Marie Skłodowska-Curie grant (grant No 752094), part of the European Union’s Horizon 2020 research and innovation programme. Part of the present collaborative work was also materialised in the framework of a short Term Scientific Mission (STSM) of the HARMONIOUS Cost Action which financially supported Dr Petropoulos’ visit between 4 to 15 February 2020 to the Department of Engineering of the University of Palermo, Italy. Η συμμετοχή του Δρ. Πετρόπουλου χρηματοδοτήθηκε από το πρόγραμμα της Ευρωπαϊκής Ένωσης για Έρευνα και Καινοτομία «Oρίζοντας 2020», δράση Marie Sklodowska - Curie , έργο ENViSIoN-EO (αριθ. 752094). Επίσης μέ…

Detecting biophysical and geometrical characteristics of the canopy of three olive cultivars in hedgerow planting systems using an UAV and VIS-NIR ca…

2021

The success of olive (Olea europaea) orchards depends on the interaction between genotype, planting system and orchard management. Research efforts often collide with the lack of high-throughput monitoring technologies for effective and rapid evaluation of expressed phenotypes under field conditions. Rapid phenotyping technologies allow to acquire a large amount of information in a relatively short period, optimizing efforts and labor. In an experiment carried out in Sicily, an unmanned aerial vehicle (UAV) equipped with VIS-NIR cameras was used to monitor canopy characteristics of three olive cultivars (‘Koroneiki’, ‘Biancolilla’ and ‘Calatina’), planted at three different planting distanc…

Time Series Analysis of Climatic Vegetation Data in the Oreto Watershed in Sicily

2008

Time series analysis of climate and vegetation variables in the Oreto watershed (Sicily, Italy)

2008

A low-cost multispectral imaging system for the characterisation of soil and small vegetation properties using visible and near-infrared reflectance

2022

Current Proximal Sensing technologies are based on multispectral imaging systems able to capture images in a few spectral bands, usually centred in VIS and NIR regions, to derive vegetation indices. However, most of such systems lack an internal radiometric calibration to estimate the actual reflectance of the observed target, making them sensitive to the local radiative environment and requiring a per-session calibration against a reference target. To overcome such dependence, the instrument described adopts an active illumination of the target surface, allowing the monitoring of soil and low vegetation surfaces by a radiometrically pre-calibrated imaging camera. The system, driven by a mi…

Metodo per il monitoraggio di superfici vegetali

2019

Si descrive un metodo da impiegare per la caratterizzazione delle coperture vegetali. A method to be used for the monitoring of vegetation surfaces is described, which includes the use of a device for measuring the spectral reflectance of vegetation using images acquired with a lightening system based on visible and infrared monoband LEDs and including devignetting, image cropping, radiometric calibration procedures and calculation of reflectance values and vegetation indices.