Search results for "satellite"
showing 10 items of 1031 documents
Centennial olive trees as a reservoir of genetic diversity
2011
†Background and Aims Genetic characterization and phylogenetic analysis of the oldest trees could be a powerful tool both for germplasm collection and for understanding the earliest origins of clonally propagated fruit crops. The olive tree (Olea europaea L.) is a suitable model to study the origin of cultivars due to its long lifespan, resulting in the existence of both centennial and millennial trees across the Mediterranean Basin. †Methods The genetic identity and diversity as well as the phylogenetic relationships among the oldest wild and cultivated olives of southern Spain were evaluated by analysing simple sequence repeat markers. Samples from both the canopy and the roots of each tr…
Genetic variation of an Italian long shelf-life tomato (Solanum lycopersicon L.) collection by using SSR and morphological fruit traits
2014
The recovery of ancient germplasm in tomato (Solanum lycopersicon L.) has become necessary to limit the wide genetic erosion caused by the employment of modern cultivars. Among germplasm collections, long shelf-life landraces could represent an important source of biodiversity. The present study provides a first set of molecular and phenotypic data on long shelf-life (so called "da serbo" in southern Italy) tomato collection, mainly originated from Sicily together with some landraces from Campania and Apulia. The analysis of fruit traits showed a low intra-varietal variation, while exhibiting a quite higher inter-varietal variability. Overall, the cultivars have been classified in six fruit…
Assessment of genetic diversity of Latvian and Swedish sweet cherry (Prunus avium L.) genetic resources collections by using SSR (microsatellite) mar…
2009
Abstract Three previously described highly polymorphic SSR (microsatellite) primer pairs were tested on 126 sweet cherry ( Prunus avium L.) accessions to adapt a fast, reliable method for preliminary screening of sweet cherry germplasm collections and to compare two sweet cherry germplasm collections: at the Latvia State Institute of Fruit-Growing, Dobele (LIFG-Dobele) and at the Division of Horticultural Genetics and Plant Breeding at Balsgard, Department of Crop Sciences, Swedish University of Agricultural Sciences (SLU-Balsgard). The SSR loci were highly polymorphic with 4–10 different alleles and 5–18 genotypes. Heterozygosity values ranged from 0.431 to 0.809, gene diversity (PIC) valu…
Characterization of five sour orange clones through molecular markers and leaf essential oils analysis.
2006
Five clones of sour orange (Citrus aurantium L.) showing significant morphological differences were selected from our germplasm collection and characterized both by genetic and leaf volatiles analysis. The genetic studies were undertaken by the use of molecular markers developed by PCR-based techniques (ISSR and RAPD), while the leaf essential oil patterns were obtained by chromatographic and mass spectrometric determination. Data obtained suggest that reasonably similar information can be achieved from the two techniques, supporting each other in characterization studies.
Intercomparison of remote-sensing based evapotranspiration algorithms over amazonian forests
2019
Abstract Evapotranspiration (ET) is considered a key variable in the understanding of the Amazonian tropical forests and their response to climate change. Remote-Sensing (RS) based evapotranspiration models are presented as a feasible means in order to provide accurate spatially-distributed ET estimates over this region. In this work, the performance of four commonly used ET RS models was evaluated over Amazonia using Moderate Resolution Imaging Spectroradiometer (MODIS) data. RS models included i) Priestley-Taylor Jet Propulsion Laboratory (PT-JPL), ii) Penman-Monteith MODIS operative parametrization (PM-Mu), iii) Surface Energy Balance System (SEBS), and iv) Satellite Application Facility…
Near real-time estimation of Sea and Land surface temperature for MSG SEVIRI sensors
2020
Abstract Land and Sea Surface Temperatures (LST and SST) are both recognized as Essential Climate Variables, and are routinely retrieved by a wealth of satellites. However, for validated approaches, the latest data are usually not available to the general public. We offer to bridge this gap, by using Meteosat Second Generation (MSG) Spinning Enhanced Visible and InfraRed Imager (SEVIRI), with its 15 min temporal resolution. Here, we present generic algorithms for the retrieval of both LST and SST, valid for the SEVIRI instrument onboard MSG platforms 8–11, which we validate using hourly data of 4 ground stations and 11 buoys in Spain over the years 2015 to 2018. These validations show that …
A simple method to directly retrieve reference evapotranspiration from geostationary satellite images
2013
Abstract Application of FAO-56 methodology for the assessment of reference evapotranspiration, ET 0 , is challenging in areas of the world with sparse meteorological network stations. For this reason alternative procedures using remotely observed data have been proposed in the literature. In this work, a simplified version of the Makkink approach [J. Inst. Wat. Eng. 11: 277–288, 1957] was tested in a typical Mediterranean environment (Sicily, Italy). The implemented Makkink approach (MAK) uses remotely estimated solar radiation derived from Meteosat Second Generation (MSG) satellite data and in situ observations of air temperature to assess ET 0 at daily time scale. Alternatively, taking ad…
Multitemporal analysis of PAL images for the study of land cover dynamics in South America
2006
Pathfinder AVHHR Land (PAL) database has been used for the retrieval of Land Surface Temperature (LST) over South America, which, along with NDVI parameter, will allow the studying of the evolution of the vegetation between July 1981 and September 2001. To this end, a classification has been built, based on PAL NDVI and Reanalysis air temperature at 2 m height data. This classification takes into account both vegetation and thermal patterns, and has been validated by a comparison with CAZALAC's map of arid zones (Centro del Agua para Zonas Aridas y semiaridas de Latino-America y el Caribe), as well as with Global Land Cover Characteristics' classification built by the USGS (United States Ge…
Estimating the phenological dynamics of irrigated rice leaf area index using the combination of PROSAIL and Gaussian Process Regression
2021
The growth of rice is a sequence of three different phenological phases. This sequence of change in rice phenology implies that the condition of the plant during the vegetative phase relates directly to the health of leaves functioning during the reproductive and ripening phases. As such, accurate monitoring is important towards understanding rice growth dynamics. Leaf Area Index (LAI) is an important indicator of rice yields and the availability of this information during key phenological phases can support more informed farming decisions. Satellite remote sensing has been adopted as a proxy to field measurements of LAI and with the launch of freely available high resolution Satellite imag…
Laboratory calibration and field measurement of land surface temperature and emissivity using thermal infrared multiband radiometers
2019
Accurate ground measurements of land surface temperature (LST) are necessary for validating satellite LST products. In order to provide reliable data, ground radiometers must be calibrated with reference to an international standard, and radiometric temperatures must be corrected for land surface emissivity. As opposed to water, land surface emissivity is not usually known for many ground covers, so an emissivity value has to be assumed, assigned from spectral emissivity libraries or measured for each land cover and spectral band considered. The aim of this study is to show the laboratory calibration and the methodology for simultaneous field measurements of LST and emissivity employed in t…