Mapping probabilities of precipitation occurrence on the territory of the Republic of Serbia by the method of indicator kriging

This paper presents the application of indicator kriging as a geostatistical method for the purpose of creating maps of precipitation occurrence probabilities on the territory of the Republic of Serbia for distinctive months during 2009. The difference between this approach to mapping and standard isohyetal maps, which describe precipitation intensity, lies in the fact that this approach points to the potential of the occurrence of a certain amount of precipitation at a specific location for a given time period. [Projekat Ministarstva nauke Republike Srbije, br. III 47014, br. TR 36009 i br. III 43007

Evaluation of scientific CMOS sensors for sky survey applications

Scientific CMOS image sensors are a modern alternative for a typical CCD detectors, as they offer both low read-out noise, large sensitive area, and high frame rates. All these makes them promising devices for a modern wide-field sky surveys. However, the peculiarities of CMOS technology have to be properly taken into account when analyzing the data. In order to characterize these, we performed an extensive laboratory testing of Andor Marana sCMOS camera. Here we report its results, especially on the temporal stability and linearity, and compare it to the previous versions of Andor sCMOS cameras. We also present the results of an on-sky testing of this sensor connected to a wide-field lens, and discuss its applications for an astronomical sky surveys.Comment: Accepted to Astronomische Nachrichte

The Electrochemical Deposition of Zn-Mn Coating from Choline Choloride-urea Deep Eutectic Solvent

Electrochemical and microscopic techniques were used for characterization of Zn˗Mn coatings electrodeposited from choline chloride˗urea deep eutectic solvent. Cyclic voltammograms show that there was no discernible Mn reduction peak when only Mn2+ was present in DES solution. The distinct Mn peak developed only upon addition of Zn2+ to the solution, probably due to previous Zn nucleation on the steel substrate. It was found that 22-27 wt.% Mn, was deposited at current densities of 3-8 mA cm-2, amounts significantly higher than in aqueous electrolytes. Since higher deposition current densities resulted in the formation of a porous surface consisting of clusters of nodular crystallites, the optimal deposition c.d was determined to be 3 mA cm˗2

Digitalni modeli terena - primarna geomorfometrijska baza podataka u GIS-u

Daljim razvojem tehnologije prikupljanja, obrade i vizuelizacije podataka o reljefu terena, DMT postaje sve više standardni produkt prikaza reljefa. Osobenosti ove baze podatka o visinama terena i njihova evidencija na računarskim medijima, omogućava da se primenom jednostavnih algoritama dođe do kvantitativnih geomorfoloških parametra. Savremeni softverski paketi za modeliranje terena, sve više uvode računanje ovih parametra kao standardne korisničke funkcije. Iz datih razloga može se očekivati da DMT sve više potiskuje ostale materijale koji se koriste u geomorfometrijskoj analizi. DMT koji je u fazi izrade na Vojno Geografskom Institutu predstavljaće nacionalnu bazu podataka o visinama za teritoriju cele Srbije i Crne Gore i svojim višenamenskim karakterom, parametrima tačnosti i dimenzijama grida, činiće dobru osnovu za geomorfometrijske analize na teritoriji cele države

Is the Second Demographic Transition a useful framework for understanding the spatial patterns of fertility change in Serbia at the beginning of the 21st century?

Gaps in comprehension of demographic change in the region of ex-Yugoslavia after 1990, caused by a lack of reliable data series, frequent change of borders, and distinctive historical and cultural tradition in comparison to other post-communist societies, motivated us to contribute to the understanding of the spatial diffusion of recent profound fertility changes in South-Eastern Europe. We analysed changes in the spatial pattern and distribution of typical fertility indicators of the second demographic transition at the sub-national level in Serbia in order to find out whether these demographic shifts could be interpreted to be similar to those in Central and Eastern Europe. We found that differences in economic, historical, and cultural development between sub-regions of the country strongly affect spatial patterns of fertility change. Also, this paper suggests that the sub- regions forerunners of the first demographic transition could be considered as the cores of diffusion for the second demographic transition

Prilog istraživanju nesigurnosti digitalnih modela terena kao primarne baze podataka topografskih informacionih sistema

U radu je razmatran uticaj nesigumosti DMT-a na rezultate analiza u kojima se ova baza podataka о prostoru koristi. Za primer je izabrana kvantitativna geomorfološka analiza, odnosno izračunavanje primamih topografskih parametara, kao sto su nagib, aspekt i zakrivljenost terena. Topografski parametri kvantitativno oslikavaju teren i sami po sebi čine bazu podataka о reljefu, koja je sastavni deo Topografskih informacionih sistema (TIS). Računanje vrednosti topografskih parametara je posebno pogodno u DMT-u sa gridnom strukturom podataka. Visine terena u DMT-u su atributi tačaka, koje su osnovni entitet ovih baza. Ovakva struktura podataka DMT-a se naziva 2.5D GIS organizacijom podataka. S obzirom na tu činjenicu analiza nesigumosti DMT-a tretirana je kao ocena atributske tačnosti podataka. Kao osnovna mera tačnosti koristi se srednja kvadratna greška visina u DMT-u, dobijena na osnovu mreže kontrolnih tačaka koje su hijerarhijski veće tačnosti u odnosu na visine u DMT-u. Veoma važan podatak u analizi je i korelativna zavisnost grešaka visina u DMT-u, koja je sračunata kovarijacionom analizom reziduuma visina DMT-a i visina kontrolne mreže tačaka. Na test području "Zlatibor" za DMT dobijen digitalizacijom orohidrografskih oleata osnovne državne karte R= 1:5000 sračunate su srednja kvadratna greška visina i korelaciona dužina grešaka visina, i one iznose 1.3m i 110m, respektivno. Ovi podaci korišćeni su u daljem postupku ocene nesigumosti DMT-a na test području "Zlatibor". U radu su primenjene dve metode za ocenu kvaliteta DMT-a. Prva se zasniva na Monte Karlo metodi stohastičkih simulacija polja grešaka sa srednjom kvadratnom greškom visine i korelacionom dužinom kao ulaznim parametrima. Tako generisana polja grešaka, koja su istih dimenzija i rezolucije kao polazni grid, dodaju se na njega. Na taj način se dobijaju moguée realizacije DMT-a iz kojih se statističkom obradom dobijaju podaci о najverovatnijim vrednostima topografskih parametara i njihovim standardnim greškama za svaku ćeliju grida. U radu je pokazano da se sa relativno malim brojem generisanih simulacija (25) mogu dobiti statistički pouzdani podaci. Druga metoda je analitički postupak ocene nesigumosti DMT-a i zasniva se na Gausovom zakonu о prenosu grešaka. Metoda se svodi na teorijsko izvođenje za greške funkcija topografskih parametara. Praktičan problem koji nastaje uzimanjem u obzir korelisanosti grešaka visina, prevaziđen je jednostavnim numeričkim rešenjem. Rezultati dobijeni na ovaj način potvrđeni su poređenjem sa rezultatima dobijenim stohastičkim simulacijama. Primenom standardnih statističkih postupaka potvrđen je visok stepen saglasnosti rezultata dobijenih ovim metodama, i to za sve topografske paramétré. U radu je posebno razmatran projektni pristup određivanja kontrolnih mreža tačaka u cilju dobijanja pouzdanih rezultata koji su potrebni za ocenu kvaliteta DMT-a. Na jednom klasičnom GIS upitu, kao što je analiza dogledanja terena, pokazano je kakav uticaj može imati nesigumost DMT-a, i kako se taj uticaj može prikazati pomoću karata verovatnoéa, i u drugim primenama DMT-a. DMT sa gridnom strukturom podataka predstavlja pogodnu bazu za proračune kao sto su geomorfometrijske analize. Međutim, njihov glavni nedostatak je ograničena mogućnost nadogradnje u kvalitativnom smislu. Primenom kokriging geostatističke interpolatone metode u radu je prikazano moguće rešenje ovoga problema sa zadovoljavajućim rezultatom. Sa relativno malim brojem naknadno merendi tačaka na terenu (156 tačaka) srednja greška visina u polaznom DMT-u je sa 1.3077? svedena na 1.22m.This work deals with the influence of DTM's uncertainty on the results of analysis where this kind of spatial data base is used. Geomorphometric analysis, more exactly calculation of primary topographic indices (parameters), like slope, aspect and curvature of the terrain, were chosen as a case study. Topographic indices are quantitative characteristics of terrain and they are also a data base of relief, which is a segment of Topographic Information System (TIS). Estimation of the topographic indices is especially suitable with grid DTM's, called digital elevation models (DEM). Terrain heights are attributes of points as basic entities in this kind of spatial date bases. This kind of data structure is well known as 2.5D GIS data bases. In respect to this, uncertainty assessment of DTM is treated as attribute accuracy estimation. A standard deviation of height error is used as a basic accuracy measure, and it is obtained from control network points which are more accurate than in DTM's heights. Very important information in this kind of analysis is correlation dependence of height errors, obtained by covariance analysis of DTM heights and residuums of control point. For DTM obtained by digitalization of contours layer of Base State Map (S = 1:5000) at test area "Zlatibor", standard deviation of height error and correlation distance were calculated to be 1.30m and 110m, respectively. These data have been used in the further procedure of uncertainty assessment of DTM's on the same test area. Two methods for DTM quality assessment were used in this work. The first one is based on the Monte Carlo method of stochastic simulations of error fields, with standard deviation of height error and correlation distance as entry parameters. The error fields, generated by this way, and which are of the same dimension and resolution as the initial grid, were added to it. Thus, the possible realizations of DTM were obtained, and data related to the most probable values of topographic parameters, as well as of their standard errors for the each grid cell, were obtained by statistical data processing. It was shown in this work that with relatively small number of generated simulations (25) statistically reliable data could be acquired. Second method is analytical approach of DTM uncertainty assessment is based on Gaussian law of error propagation. This method is based on theoretical evaluation of error function of topographic parameters. The problem which arises when correlation of heights errors is taken into account could be solved by a simple numerical solution for this method of uncertainty assessment. The results obtained by this way were verified by comparing them with the ones obtained by stochastic simulations. The high level of agreement of the results obtained by these two methods, for all topographic parameters, was confirmed by standard statistical procedures The project procedure for establishing the control networks, with the aim of getting reliable results necessary for DTM quality assessment, was particularly examined in this work. The influence of DTM uncertainty, as well as the method of its presentation (probability maps) in the other DTM applications, were shown in a classical GIS query, such as a viewshed analysis

Modelling the spatial distribution of Vojvodina's population by using dasymetric method

Cartographic presentation of heterogeneity/homogeneity in the spatial distribution of population is still a major problem in modern geography, and other geo-sciences as well. The traditional method of thematic or choropleth mapping rarely gives satisfactory results. This paper analyzes the applicability of dasymetric mapping method for the modelling of spatial distribution of population. Although it is a relatively old method, it becomes widely used following the development of computer technology, GIS and satellite imagery, and its applicability is increasing in social, economic and other sciences and disciplines. After showing the basis and development of dasymetric mapping, the authors present possible application of this method in the population distribution modelling of Vojvodina