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GPS Solutions - We present the methodology and results of GPS/GLONASS integration in network code differential positioning for regional coverage across Poland using single frequency. Previous... 相似文献
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The Sudetes Mountains (Central Europe) were under a particularly intense long-term air pollution load during the 1970s and 1980s. Intense industrial activity in this area led to large-scale forest dieback and reductions in tree growth rates, potentially limiting the use of tree-ring data from this region in dendroclimatic research. In this paper, ring-width chronologies were constructed for 493 Norway spruce trees (Picea abies L. Karst.) from 17 sampling sites within five major mountain ranges in the Sudetes Mountains of Poland. Growth-climate response data indicate that April?July temperatures are the main factor affecting radial growth of trees in the study area. Our data also indicate the strong influence of slope aspect on temperature signal strength. The lowest correlation values were obtained for sites located on western slopes with effective fog deposition, which are strongly affected by pollution. An appropriate sampling strategy resulted in the creation of a temperature-sensitive proxy record (rAMJJ = 0.70), exceptional for areas under strong pressure from human activity. Based on a regional master chronology, growing season (April?July) temperatures over the past 200 years were then reconstructed. Four warm and four cold periods were distinguished and compared with other reconstructions and long-term instrumental data. 相似文献
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Mieczysław Ostojski 《Acta Geophysica》2013,61(3):690-705
This paper presents an application of hydrological and hydraulic models for transferring instantaneous discharges from a water gauge station to budgeting sites on rivers. Calculations were done using the following models: MIKE NAM rainfall-runoff model and a hydrodynamic MIKE 11 HD model. The simulations were carried out for the catchment of Warta River and its tributaries for the multiyear period 1999–2009. 相似文献
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Żaneta Polkowska Mieczysław Sobik Marek Błaś Kamila Klimaszewska Barbara Walna Jacek Namieśnik 《Journal of Atmospheric Chemistry》2009,62(1):5-30
Hoarfrost and rime analysis was based on the collection of samples between 2003 and 2006 from 8 sites, which represent both
lowland (northern) and mountainous (southern) parts of Poland. On the other hand 4 of these sites belong to “urban” and 4
to “rural” category. pH, conductivity, SO42−, NO3−, Cl−, H+, NH4+, Ca2+, Mg2+, Na+, K+ have been determined in order to study the chemistry of hoarfrost and rime. Higher total inorganic ionic content (TIC) in
hoarfrost and rime (2.46 meq·l−1 and 1.23 meq·l−1 respectively) was observed when compared with precipitation (0.37 meq·l−1). Large variability of TIC and chemical composition of individual samples were typical at each of the measurement sites depending
on emission patterns, atmospheric conditions and local terrain topography. Higher concentrations of both hoarfrost and rime
occurred in southern (mountainous) rather than in northern (lowland) part of Poland which can be explained by worse pollutant
dispersion conditions in the south. The surprisingly low hoarfrost concentrations in urban coastal stations in the area of
the Bay of Gdansk were attributed to the cleaning effect of nocturnal breeze-type circulation, best pronounced in cool part
of the year. Due to relatively high pollutant concentration and long duration, hoarfrost and rime are at least significant
factors in environmental processes in different ecosystems in Poland. 相似文献
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Precise estimation of covariance parameters in least-squares collocation by restricted maximum likelihood 总被引：1，自引：0，他引：1
Precise estimates of the covariance parameters are essential in least-squares collocation (LSC) in the case of increased accuracy requirements. This paper implements restricted maximum likelihood (REML) method for the estimation of three covariance parameters in LSC with the Gauss-Markov second-order function (GM2), which is often used in interpolation of gravity anomalies. The estimates are then validated with the use of an independent technique, which has been often omitted in the previous works that are confined to covariance parameters errors based on the information matrix. The crossvalidation of REML estimates with the use of hold-out method (HO) helps in understanding of REML estimation errors. We analyzed in detail the global minimum of negative log-likelihood function (NLLF) in the estimation of covariance parameters, as well, as the accuracy of the estimates. We found that the correlation between covariance parameters may critically contribute to the errors of their estimation. It was also found that knowing some intrinsic properties of the covariance function may help in the scoring process. 相似文献
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This paper analyses the possibility of using integrated GPS (Global Positioning System) surveys and ground penetrating radar surveys to precisely locate damages to levees, particularly due to the activity of small fossorial mammals. The technology of intercommunication between ground penetrating radar (GPR) and an RTK (Real-Time Kinematic) survey unit, and the method of data combination, are presented. The errors which may appear during the survey work are also characterized. The procedure for processing the data so that the final results have a spatial character and are ready to be implemented in digital maps and geographic information systems (GIS) is also described. 相似文献
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