Hα Photometry of Two Contact Binaries

We carried out optical and Hα photometry of two contact binaries (V861 Herculis, EQ Tauri). The light curve modeling revealed stellar spots in both contact systems and strong Hα excess in the position of the observed stellar spots. A correlation was found between the V−R and R−H_α colour indices of V861 Her.     

Possibilities of land use change analysis in a mountainous rural area: a methodological approach

Decreasing population density is a current trend in the European Union, and causes a lower environmental impact on the landscape. However, besides the desirable effect on the regeneration processes of semi-natural forest ecosystems, the lack of traditional management techniques can also lead to detrimental ecological processes. In this study we investigated the land use pattern changes in a micro-region (in North-Eastern Hungary) between 1952 and 2005, based on vectorised land use data from archive aerial photos. We also evaluated the methodology of comparisons using GIS methods, fuzzy sets and landscape metrics. We found that both GIS methods and statistical analysis of landscape metrics resulted in more or less the same findings. Differences were not as relevant as was expected considering the general tendencies of the past 60 years in Hungary. The change in the annual rate of forest recovery was 0.12%; settlements extended their area by an annual rate of 3.04%, while grasslands and arable lands had a net loss in their area within the studied period (0.60% and 0.89%, respectively). The kappa index showed a smaller similarity (~60%) between these dates but the fuzzy kappa and the aggregation index, taking into account both spatial and thematic errors, gave a more reliable result (~70–80% similarity). Landscape metrics on patch and class level ensured the possibility of a detailed analysis. We arrived at a similar outcome but were able to verify all the calculations through statistical tests. With this approach we were able to reveal significant (p < 0.05) changes; however, effect sizes did not show large magnitudes. Comparing the methods of revealing landscape change, the approach of landscape metrics was the most effective approach, as it was independent of spatial errors and ensuring a multiple way of interpretation.     

Quantifying land use/land cover spatio-temporal landscape pattern dynamics from Hyperion using SVMs classifier and FRAGSTATS®

This study aims to quantify the landscape spatio-temporal dynamics including Land Use/Land Cover (LULC) changes occurred in a typical Mediterranean ecosystem of high ecological and cultural significance in central Greece covering a period of 9 years (2001–2009). Herein, we examined the synergistic operation among Hyperion hyperspectral satellite imagery with Support Vector Machines, the FRAGSTATS^® landscape spatial analysis programme and Principal Component Analysis (PCA) for this purpose. The change analysis showed that notable changes reported in the experimental region during the studied period, particularly for certain LULC classes. The analysis of accuracy indices suggested that all the three classification techniques are performing satisfactorily with overall accuracy of 86.62, 91.67 and 89.26% in years 2001, 2004 and 2009, respectively. Results evidenced the requirement for taking measures to conserve this forest-dominated natural ecosystem from human-induced pressures and/or natural hazards occurred in the area. To our knowledge, this is the first study of its kind, demonstrating the Hyperion capability in quantifying LULC changes with landscape metrics using FRAGSTATS^® programme and PCA for understanding the land surface fragmentation characteristics and their changes. The suggested approach is robust and flexible enough to be expanded further to other regions. Findings of this research can be of special importance in the context of the launch of spaceborne hyperspectral sensors that are already planned to be placed in orbit as the NASA’s HyspIRI sensor and EnMAP.     

Doppler Images of ζ Andromedae

Doppler images are presented for the RS CVn-type binary ζ And. Our upgraded Doppler imaging code TempMap_ε takes into account the distorted geometry of the primary giant component. On the maps several low latitude spots are restored with a temperature contrast of about 1000 K. Some weak polar features are also found. Cross-correlation of the consecutive Doppler-maps suggests solar-like differential surface rotation.     

Landscape transform and spatial metrics for mapping spatiotemporal land cover dynamics using Earth Observation data-sets

Analysis of Earth observation (EO) data, often combined with geographical information systems (GIS), allows monitoring of land cover dynamics over different ecosystems, including protected or conservation sites. The aim of this study is to use contemporary technologies such as EO and GIS in synergy with fragmentation analysis, to quantify the changes in the landscape of the Rajaji National Park (RNP) during the period of 19 years (1990–2009). Several statistics such as principal component analysis (PCA) and spatial metrics are used to understand the results. PCA analysis has produced two principal components (PC) and explained 84.1% of the total variance, first component (PC1) accounted for the 57.8% of the total variance while the second component (PC2) has accounted for the 26.3% of the total variance calculated from the core area metrics, distance metrics and shape metrics. Our results suggested that notable changes happened in the RNP landscape, evidencing the requirement of taking appropriate measures to conserve this natural ecosystem.     

Die mit einer Drehwaage messbare Massenwirkung eines „zweidimensionalen” Parallelepipeden in der vertikalen Ebene

Summary The gravimetric effect of a two dimensional parallelepipedon measurable by Torsion Balance in the vertical plane is examined. It is found that the places of the equal gradients and curvatures of a rectangle stretching into the infinity are orthogonal circles. The gradients and curvatures of a parallelogramm (stretching into the infinity) which has the finite side in common with the rectangle are expressed by those of the latter, their extreme values lie along isosceles hyperbolas.

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Riassunto Si esamina l'azione gravimetrica di un parallelepipedo bidimensionale in base agli elementi misurabili con la bilancia di torsione nel piano verticale. Risulta che il luogo dei punti di eguali gradienti e curvature di un parallelogrammo pure estendentesi all'infinito con il lato finito in comune col rettangolo sono esprimibili a mezzo degli analoghi elementi di quest'ultimo ed 1 loro valori estremi risultano distribuiti lungo iperboli isosceli.

     

Long-Term Evolution of FU Ori-Type Stars at Infrared Wavelengths

We investigated the brightness evolution of 5 FU Ori systems in the 1–200 μm wavelength range using observations from the Infrared Space Observatory, 2MASS and MSX data. The SEDs were compared with earlier ones derived from the IRAS photometry and ground-based observations around the epoch 1983. In three cases no difference was seen, in one object the near- and mid-infrared part of the spectrum became fainter by a factor of 2, and in the fifth case a marginal fading was observed. We study in detail the case of V1057 Cyg.     

Modelling of land use land cover change using earth observation data-sets of Tons River Basin,Madhya Pradesh,India

Abstract

An integrated Markov Chain and Cellular Automata modelling (CA MARKOV), multicriteria evaluation techniques have been applied to produce transition probability. The unsupervised method was employed to classify the satellite images of year 1985, 1995, 2005 and 2015 to meet the magnitude of LULC change. Results showing the spatial pattern of the sub-basin is largely influenced by the biophysical and socio-economic drivers leading to growth of agricultural lands and built-up area in the basin. Simulated plausible future LULC changes for 2025 which is based on a CA MARKOV that integrates Markovian transition probabilities computed from satellite-derived LULC maps and a CA contiguity spatial filter (5 × 5). Further, the fragmentation analysis was performed to check the fragmentation scenario in the year 2025. The result for year 2025 with reasonably good accuracy will be useful to the planners, policy- and decision-makers.     

Die kartographische Methode von R. Eötvös in ihrer heutigen Form

Summary The Torsion Balance is to be used only in case if more information than presented by the Gravimeter is required. Being so, it is advisable then to make most of the fineness obtainable by the Torsion Balance. Therefore, a survey must be done carefully and reliably. One of its accessories is a proper calculus of the cartographic effects, specially for the curvature data which in their crude state — over a hilly topography — are of not much use. The cartographic method of Eötvös is right, for it works with a prism resting over a circle parcel which best fits the contourlines. The method itself is good, but Eötvös's approximate formulae — simple as they are — are accurate only within 2/10s of topographic elevation or depression. Generally speaking this limit is sufficient for the curvature data as beyond it they are rarely reliable. In order to speed up their evaluations from the map the author drew up a scale. On the other hand, for the gradient-effects a table was computed; it contains the effects of prisms of different heights at different distances. This table is handy in use; the basis used for it is the exact formula of gradient-effect. Same has to be done for curvature data beyond the two-tenth elevation. Suitably constructed tables for both effects may also be used for masses of three dimensions.

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Szilárd Oslaczky, Mitarbeiter des Instituts für Geodäsie und Markscheidekunde der Technischen Universität inSopron, Obergeophysiker beim MAORT.     

Effect of soil parameters on the threshold wind velocity and maximum eroded mass in a dry environment

The present study aims to investigate the relationships between several soil parameters (texture, organic matter and CaCO₃ content) and the threshold wind velocity and erodibility of different soil types. Our aim was to determine the role of these soil parameters play in soil loss due to wind erosion and also to statistically evaluate these correlations. The erodibility studies were carried out in wind tunnel experiments, and the resulting data were analysed with multiple regression analysis and the Kruskal-Wallis test. We found that both the threshold wind speed and the erodibility of soils were mostly determined by silt fraction (0.05–0.02 mm), while sand fractions had a lesser effect on it. Our experiences with organic matter and CaCO₃ similar, i.e. in spite of their correlation with the erosion, their contribution was not significant in the multivariate regression model. Consequently, based on mechanical composition of soils, one can predict threshold wind velocity and erodibility of soils.