David Gómez-Candón

Aula Dei Technological Science Park Foundation · ARAID

This study considers critical aspects of water management and crop productivity in wheat cultivation, specifically examining the daily cumulative actual evapotranspiration (ETa). Traditionally, ETa surface energy balance models have provided estimates at discrete time points, lacking a holistic integrated approach. Field trials were conducted with...

The development of accurate grain yield (GY) multivariate models using normalized difference vegetation index (NDVI) assessments obtained from aerial vehicles and additional agronomic traits is a promising option to assist, or even substitute, laborious agronomic in-field evaluations for wheat variety trials. This study proposed improved GY predict...

This research aimed at analyzing the response of apple tree varieties subjected to soil water deficit and atmospheric drought in a field phenotyping platform located in the Mediterranean area. The main assumption of the study was that seasonal and daily stomatal behavior can be monitored by continuous measurement of canopy surface temperature (Ts)...

Principles and functioning of thermal imaging Acquisition process with TIR UAV TIR images (pre-)processing Analyzing TIR images acquired by UAV Challenges and limits

The book serves as a handbook and guideline for the application of UAV-based remote sensing. Data acquisition, processing and interpretation was explained in-depth, and was correlated by a variety of practical examples and case studies. Open Access book available at: https://www.wbg-wissenverbindet.de/shop/42282/uavs-for-the-environmental-sciences

Wheat and rice are two main staple food crops that may suffer from yield losses due to drought episodes that are increasingly impacted by climate change, in addition to new epidemic outbreaks. Sustainable intensification of production will rely on several strategies, such as efficient use of water and variety improvement. This review updates the la...

The current lack of efficient methods for high throughput field phenotyping is a constraint on the goal of increasing durum wheat yields. This study illustrates a comprehensive methodology for phenotyping this crop's water use through the use of the two-source energy balance (TSEB) model employing very high resolution imagery. An unmanned aerial ve...

This work assesses the use of aerial imagery for the vegetation cover characterization in cork oak woodlands. The study was conducted in a cork oak woodland in central Portugal during the summer of 2017. Two supervised classification methods, pixel-based and object-based image analysis (OBIA), were tested using a high spatial resolution image mosai...

This paper describes the current status of the measurement of the spatial variability of water status at tree scale in fruit crops through remote sensing, and discusses the limitations and opportunities of these technologies. Remotely sensed multispectral and thermal imagery can provide high precision water status maps in orchards through stress in...

Les images thermiques ont de nombreuses applications dans le domaine agronomique, notamment pour informer sur la réponse des plantes au stress hydrique. La miniaturisation des caméras thermiques permet aujourd'hui de les installer sur des drones. Cependant, les caméras thermiques miniaturisées embarquées à bord de drones n'ont pas de système de con...

Water stress assessment can be performed by analyzing thermal images taken onboard Unmanned Aerial Vehicles (UAVs). This study focuses on the acquisition and data extraction of high-resolution UAV-sensed thermal images. The datasets obtained, through computation of spectral indices and image classification, allowed to assess the response to drought...

Numerous agronomical applications of remote sensing have been proposed in recent years, including water stress assessment at field by thermal imagery. The miniaturization of thermal cameras allows carrying them onboard the unmanned aerial vehicles (UAVs), but these systems have no temperature control and, consequently, drifts during data acquisitio...

Highlights: The purpose of this study was to evaluate the performance of a miniaturized thermal camera compared with a self-cooled thermal camera. A Blackbody was used as reference and the observed parameters were stability and noise of the sensors. Results revealed that, after pre-heating, both cameras showed similar precision and accuracy. Miniat...

Water stress assessment can be performed by analyzing thermal images taken onboard Unmanned Aerial Vehicles (UAVs). This study focuses on the acquisition and data extraction of high-resolution UAV-sensed thermal images. The datasets obtained, through computation of spectral indices and image classification, allowed to assess the response to drought...

A procedure named CROPCLASS was developed to semi-automate census parcel crop assessment in any agricultural area using multitemporal remote images. For each area, CROPCLASS consists of a) a definition of census parcels through vector files in all of the images; b) the extraction of spectral bands (SB) and key vegetation index (VI) average values f...

UMR AGAP - équipe AFEF - Architecture et fonctionnement des espèces fruitières(Edited by Pablo Gonzalez-de-Santos and Angela Ribeiro)

A procedure to achieve the semi-automatic relative image normalization of multitemporal remote images of an agricultural scene called ARIN was developed using the following procedures: 1) defining the same parcel of selected vegetative pseudo-invariant features (VPIFs) in each multitemporal image; 2) extracting data concerning the VPIF spectral ban...

Automatic method for the radiometric standardization of series of multitemporal remote images of one and the same geographical scene or area, on the basis of vegetative pseudo-invariant soil uses, which comprises: a) the capture of multispectral remote images corresponding to bands selected in the visible or hyperspectral spectrum, b) the digitizat...

A method was developed to normalize multitemporal remote images based in vegetative pseudo-invariant features (VPIFs), as following: 1) defining the same parcel for each selected VPIF in each multitemporal image; 2) extracting the VIPF spectral bands data for each image; 3) calculating the correction factor (CF) for each image band to fit it to the...

A new aerial platform has become available in recent years for image acquisition, the Unmanned Aerial Vehicle (UAV). This article defines and evaluates the technical specifications of an UAV and the spatial and spectral properties of the images captured by two different sensors, a still visible camera and a six-band multispectral camera, for early...

High spatial resolution images taken by unmanned aerial vehicles (UAVs) have been shown to have the potential for monitoring agronomic and environmental variables. However, it is necessary to capture a large number of overlapped images that must be mosaicked together to produce a single and accurate ortho-image (also called an orthomosaicked image)...

Georeferencing of remote imagery with high spatial resolution can be achieved using the semiAUtomatic GEOreferencing (AUGEO) system which is based on artificial terrestrial targets (ATTs) and software AUGEO-2.0 for location and georeferencing. The aim of this letter is to describe the system and validate it. The ATTs consist of colored hexagonal ta...

The aim of this study was to determine the positional accuracy of GeoEye-1 images and how it affects the delineation of the input prescription map (IPM) for site-specific strategies. Seven panchromatic and multi-spectral GeoEye-1 satellite images were taken over the LaVentilla village area (Andalusia, Spain), from April to October 2010, at an inter...

Avena sterilis weed pressure categories can be discriminated in wheat through remote images taken at late stages of wheat senescence. Site-specific image processing was achieved with SARI ® , an add-on software program for ENVI ® developed to implement precision agriculture. Using the SARI software and crop-weed competition and economic models, the...

Software was developed to spatially assess key crop characteristics from remotely sensed imagery. Sectioning and Assessment of Remote Images (SARI®), written in IDL® works as an add-on to ENVI®, has been developed to implement precision agriculture strategies. SARI® splits field plot images into grids of rectangular “micro-images” or “micro-plots”....

The aim of this paper is to assess co-registration errors in remote imagery through the AUGEO system, which consists of geo-referenced coloured tarps acting as terrestrial targets (TT), captured in the imagery and semi-automatically recognised by AUGEO2.0® software. This works as an add-on of ENVI® for image co-registration. To validate AUGEO, TT w...

Cruciferous weeds are very competitive broadleaf species and frequently infest cereal and legume crops. These weeds seriously impair crop development and cause high yield losses. Herbicides are commonly applied over an entire agricultural field although weeds are spatially distributed in patches. To reduce the herbicide use by applying them only wh...

Satellite and airborne remote sensed images cover large areas, which normally include dozens of agricultural plots. Agricultural operations such as sowing, fertilization, and pesticide applications are designed for the whole plot area, i.e. 10 to 30 ha, or through precision agriculture. This takes into account the spatial variability of biotic and...

The software SARI® has been developed to implement precision agriculture strategies through remote sensing imagery. It is written in IDL® and works as an add-on of ENVI®. It has been designed to divide remotely sensed imagery into "micro-images", each corresponding to a small area ("micro-plot"), and to determine the quantitative agronomic and/or e...