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Development of a Short-Range Multispectral Camera Calibration Method for Geometric Image Correction and Health Assessment of Baby Crops in Greenhouses
Get PDFMultispectral imaging plays a key role in crop monitoring. A major challenge, however, is spectral band misalignment, which can hinder accurate plant health assessment by distorting the calculation of vegetation indices. This study presents a novel approach for short-range calibration of a multispectral camera, utilizing stereo vision for precise geometric correction of acquired images. By using multispectral camera lenses as binocular pairs, the sensor acquisition distance was estimated, and an alignment model was developed for distances ranging from 500 mm to 1500 mm. The approach relied on selecting the red band image as a reference, while the remaining bands were treated as moving images. The stereo camera calibration algorithm estimated the target distance, enabling the correction of band misalignment through previously developed models. The alignment models were applied to assess the health status of baby leaf crops (Lactuca sativa cv. Maverik) by analyzing spectral indices correlated with chlorophyll content. The results showed that the stereo vision approach used for distance estimation achieved high accuracy, with average reprojection errors of approximately 0.013 pixels (4.485 × 10−5 mm). Additionally, the proposed linear model was able to explain reasonably the effect of distance on alignment offsets. The overall performance of the proposed experimental alignment models was satisfactory, with offset errors on the bands less than 3 pixels. Despite the results being not yet sufficiently robust for a fully predictive model of chlorophyll content in plants, the analysis of vegetation indices demonstrated a clear distinction between healthy and unhealthy plants
Changing firefighting strategies thanks to new early detection capabilities offered by Robust Satellite Techniques
No full textTimely detection of forest fires can enable rapid counteraction before they become uncontrolled and wipe out entire forests. Remote sensing, particularly when based on geostationary satellite data, can be successfully utilized for this purpose. Unlike sensors on polar orbiting platforms, instruments on geostationary satellites guarantee very high temporal resolution (from 15 to 2.5 minutes), which can be usefully employed for continuous monitoring over large areas and to detect fires at their early stages. This allows for quite a different, more effective, and less expensive management of firefighting resources. Smaller, lightly equipped but rapidly responding teams can intervene on small fires and extinguish them well before they become so extensive and dangerous as to require more expensive efforts (such as helicopters or Canadair aircraft).
This proactive approach, however, comes up against the limitations of current fire-detection algorithms (mostly based on fixed thresholds approaches), which are still unable to identify nascent fires while simultaneously avoiding the proliferation of false alarms. The result is low algorithm sensitivity, generally meaning that only large and/or extremely intense events are detected. This work describes the experience gained so far by implementing and validating an original change-detection technique (the RST-FIRES approach) to overcome these issues. Its performance in terms of reliability and sensitivity, already verified using SEVIRI data (the Spinning Enhanced Visible and Infrared Imager sensor on board the Meteosat Second Generation geostationary satellite), is currently being tested on the new FCI (Flexible Combined Imager on board the new Meteosat Third Generation satellite) within the framework of the TECH4YOU (funded by Next-Generation-EU) project.
After approximately 1,000 near-real-time ground and aerial checks of the RST-FIRES detections, the added value of the RST-FIRES technique in detecting small fires is demonstrated, with a sensitivity ranging from 3 to 70 times higher than that of any other similar SEVIRI-based product.
In this paper, we present results achieved after long-term collaboration with the Regional Civil Protection Departments and Local Authorities of the Basilicata, Lombardy, and Sicily regions. Preliminary results achieved after implementing a similar approach for MTG (with heavily enhanced instrumental and observational capabilities) within the framework of the TECH4YOU project (covering the Basilicata and Calabria regions) will also be presented
Genetica ed ecologia per la gestione sostenibile degli ecosistemi forestali: sviluppi recenti
Get PDFA Novel Time Domain Reflectometry (TDR) System for Water Content Estimation in Soils: Development and Application
Get PDFInterconnecting karst dolines with high ecological value through tourist routes for enhancing public recreation
Get PDFPlanning technical interventions in areas of high landscape and environmental importance requires the convergence of integrated multiple skills. Particularly when these areas find significant opportunities for tourist valorization, this planning activity is extremely important and requires an appropriate technical approach. With the aim to enhance public recreation in the rural land, in this paper, some areas of peculiar environmental, landscape and archaeological value - such as the karst dolines (in Italian, so-called: “Puli“) – have been analyzed. This type of karst formation originated as a result of the collapse of the vault of underground cavities, excavated by the erosive and corrosive action of water infiltrating the limestone substrata. Through the implementation of a GIS tool, some touristic routes, connecting three different „Puli“ located in the Apulia region (Southern Italy), have been examined. These three areas are very interesting as for their historical-archaeological value and their geological nature, as well as for their naturalistic assets - both faunal and botanical biodiversity, including several ecosystems. The final results coming from this research may support in sustainably enhancing public recreation in the rural landscape along specific touristic routes, helping to assess the environmental and social impact of tourism activities along those trails as well
Influence of structural deterioration of RC piers due to steel corrosion on the seismic performance of bridges
No full textThe seismic performance of typical bridge piers with corroded rebars is investigated through extensive NonLinear Static Analysis. Piers featuring different cross sections and heights, as well as different deterioration patterns and intensities, are examined. This is followed by the analysis of multi-span bridges differing in pier layout, number of spans and deterioration scenarios. The ratio between the maximum earthquake intensity level that the structure can withstand before collapse and the code-conforming intensity level for the verification of the collapse limit state is computed. The comparison of results between as-built and deteriorated models clearly proves the relevance of the problem
Noncentral moderate deviations for time-changed Lévy processes with inverse of stable subordinators
Get PDFThis paper presents some extensions of recent noncentral moderate deviation re-sults. In the first part, the results in [Statist. Probab. Lett. 185, Paper No. 109424, 8 pp. (2022)] are generalized by considering a general Lévy process {S(t): t ≥ 0} instead of a compound Poisson process. In the second part, it is assumed that {S(t): t ≥ 0} has bounded variation and is not a subordinator; thus {S(t): t ≥ 0} can be seen as the difference of two independent nonnull subordinators. In this way, the results in [Mod. Stoch. Theory Appl. 11, 43–61] for Skellam processes are generalized
Electrochemical Degradation of Venlafaxine on Platinum Electrodes: Identification of Transformation Products by LC-MS/MS and In Silico Ecotoxicity Assessment
Get PDFAntidepressants are emerging contaminants that have raised global concern due to their abuse. Venlafaxine (VFX), a serotonin and norepinephrine reuptake inhibitor, can cause adverse and potentially toxic effects on aquatic organisms. Electrochemical advanced oxidation processes (EAOPs) are gaining attention as promising degradation techniques for a variety of drugs. EAOP methods proposed for VFX degradation mainly utilize boron-doped diamond (BDD) electrodes, characterized by low background current and high oxygen overpotential. However, challenges arise, including delamination from the substrate, difficulties in scaling up, and limited service life. In this study, platinum was employed as an anode for the galvanostatic degradation of VFX, due to its stability and well-established surface cleaning procedure, which ensured high reproducibility. A 0.1 M Na2SO4 solution at pH 9 was used as the supporting electrolyte, and a current density of 25 mA/cm2 was applied. After 7 h, a degradation efficiency of 94% was achieved for a 25 ppm VFX solution. The hydroxyl and sulfate radicals generated in the electrochemical system were the active species responsible for VFX degradation, which followed a first-order kinetic model with a rate constant of 0.0084 min−1. The main degradation intermediates were identified through LC-MS, including two isomers with a nominal m/z of 276 and three isomers with a nominal m/z of 294. The toxicity of the VFX degradation products was assessed by an in silico prediction model. This evaluation confirmed the sustainability of the developed method