Search results for "satellite"
showing 10 items of 1031 documents
Astronomija. 20: Zemes mākslīgo pavadoņu lāzerlokācija
1995
Krājumā publicētajos zinātniskajos rakstos galvenokārt aplūkotas Zemes mākslīgo pavadoņu lāzerstaciju modernizācijas problēmas, kā ari īsi skarti debess mehānikas un astronomijas pedagoģijas jautājumi.
Sentinel 2 and 3 for Temperature Monitoring Over the Amazon
2018
In this work we present results of an early assessment of the performance of the Land Surface Temperature (LST) product retrieved from the Sea and Land Surface Temperature Radiometer (SLSTR) on board the Sentinel-3 satellite (S3/SLSTR) over the Amazon basin. Results are validated from comparison of S3/SLSTR retrievals against in situ measurements of surface temperature collected over one instrumented site in the Peruvian Amazon. The validation exercise was performed on the standard S3/SLSTR Level-2 LST product as well as on a dedicated LST split-window algorithm with an explicit dependence on surface emissivity. Surface emissivity maps obtained from the high spatial resolution of S2/MSI are…
A comparison of Microtops II and satellite ozone measurements in the period 2001-2011
2013
Daily average total ozone Microtops measurements obtained during several campaigns conducted from 2001 to 2011 at latitudes from 31 to 68N and in different seasons are compared with satellite observations. The Microtops ozone is derived using different wavelength combinations (Channel I, 305.5/312.5. nm; Channel II, 312.5/320. nm; and Channel III, 305.5/312.5/320. nm). Satellite data from TOMS, OMI, GOME, and GOME-2 are used in the comparison. The three Microtops channels show a high correlation with the satellite retrievals. Channel I shows the best results and produces a mean bias deviation (MBD) less than 2.14% with respect to TOMS, OMI and GOME. The MBD increases to 3% in the comparison…
Land surface temperature retrieval from LANDSAT TM 5
2004
In this paper, three methods to retrieve the land surface temperature (LST) from thermal infrared data supplied by band 6 of the Thematic Mapper (TM) sensor onboard the Landsat 5 satellite are compared. The first of them lies on the estimation of the land surface temperature from the radiative transfer equation using in situ radiosounding data. The others two are the mono-window algorithm developed by Qin et al. [International Journal of Remote Sensing 22 (2001) 3719] and the single-channel algorithm developed by Jime´nez-Mun˜oz and Sobrino [Journal of Geophysical Research 108 (2003)]. The land surface emissivity (LSE) values needed in order to apply these methods have been estimated from a…
A time domain triangle method approach to estimate actual evapotranspiration: Application in a Mediterranean region using MODIS and MSG-SEVIRI produc…
2016
Abstract In this study, spatially distributed estimates of regional actual evapotranspiration (ET) were obtained using a revised procedure of the so called “triangle method” to parameterize the Priestley–Taylor ϕ coefficient. In the procedure herein proposed, named Time-Domain Triangle Method (TDTM), the triangular feature space was parameterized considering pairs of T s –VI values obtained by exploring, for each pixel, only their temporal dynamics. This new method was developed using time series products provided by MODIS and MSG-SEVIRI sensors. Moreover the proposed procedure does not depend on ancillary data, and it is only based on remotely sensed vegetation indices and day–night time l…
L’industria dei viaggi e del turismo in Italia: aspetti definitori, dinamiche intersettoriali ed effetti della crisi
2022
The travel and tourism industry has an increasingly central role in countries’ economies due to its ability to contribute significantly to the production of various economic sectors. Despite this growing importance, the literature’s attention to analysing the productive articulations that characterise appears very limited to date. This article presents an overview of the primary lit- erature on the travel and tourism industry and then conducts a quantitative analysis through the Satellite Accounting of Tourism in Italy. Tourism consumption and production in the years 2010, 2015, 2017 and 2019 are compared, and then the effect of the pandemic is analysed by compar- ing the data in 2020. Fina…
Pnnr e le economie del turismo in Italia: disparità inter ed infra regionali e politiche di ripresa e resilienza
2022
The Italian regions show marked differences in the pattern of tourism development. These disparities can be offset by implementing a common plan supporting recovery and strengthening its resilience to external shocks. This article aims to offer a deepening of the NRPV concerning the economies of tourism and, following a regional analysis, to verify the current disparities and the initiatives of the plan to overcome them. An analysis of the Italian regions on the supply and demand front is proposed using synthetic indices of endowment and the presence of tourist demand to compare the articulation of specificities at the sub-regional level. Finally, some guidelines are suggested on policies f…
Development of International Freight Transit in Latvia
2013
Abstract International freight transit is transportation of goods through third countries which are neither senders or consumers of the transported freight. International freight transit provides the use of transport infrastructure capacities and the development of transport infrastructure in Latvia, especially in seaports and railways. In Latvia approximately 97% of all transported freight carried by railway is international freight transit. The turnover of Latvia's seaports is approximately 90% international freight transit transport. This paper describes comparative position of Latvia in Logistics Performance Index and assesses international competitiveness of Latvia's international frei…
Optimal Transit Network Design
2019
In this chapter, the optimal transit network design is under investigation. A special kind of transport is assumed to be given the best traffic conditions in a road network (the smallest amount of travel time between origins and destinations). Optimality criteria for transit network design in case of selfish routing are defined in the first section. The Sect. 7.2 is devoted to the estimation of selfish traffic assignment in a network with a transit subnetwork. Optimality criteria for transit network design in case of competitive drivers’ groups routing are defined in the Sect. 7.3. The Sect. 7.4 is devoted to traffic assignment in case of competitive drivers’ groups routing in a network wit…
Signals of major histocompatibility complex overdominance in a wild salmonid population
2009
The major histocompatibility complex (MHC) contains the most variable genes in vertebrates, but despite extensive research, the mechanisms maintaining this polymorphism are still unresolved. One hypothesis is that MHC polymorphism is a result of balancing selection operating by overdominance, but convincing evidence for overdominant selection in natural populations has been lacking. We present strong evidence consistent with MHC-specific overdominance in a free-living population of Arctic charr (Salvelinus alpinus) in northernmost Europe. In this population, where just two MHC alleles were observed, MHC heterozygous fish had a lower parasite load, were in better condition (as estimated by a…