Geoinformatics FCE CTU is a non-profit open access journal focused on science and technology related to geospatial information ranging from geodesy, surveying, geographic information systems, cartography and mapping, photogrammetry, laser scanning, cadastre and other related engineering fields; last but not least the journal focuses on promoting Free Software. Articles are licenced under Creative Commons Attribution 4.0 International licence (CC BY 4.0), have DOI and are indexed in CrossRef database and Directory of Open Access Journals (DOAJ). From Vol. 16, No. 1 (2017) we have started publishing our articles continuously. Articles included in a Future Issue are assigned DOI, registered in DOAJ database and are available from our Archives.
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Testing of the Possibilities of Using IMUs with Different Types of Movements
Inertial navigation system (INS) is a self-contained navigation technique. Its main purpose is to determinate the position and the trajectory of the object´s movement in space. This technique is well represented not only as a supplementary method (GPS/INS integrated system) but as an autonomous system for navigation of vehicles and pedestrians, also. The aim of this paper is to design a test for low-cost inertial measurement units. The test results give us information about accuracy, which determine the possible use in indoor navigation or other applications. There are described some methods for processing the data obtained by inertial measurement units, which remove noise and improve accuracy of position and orientation.
Measurement of Deformations by MEMS Arrays, Verified at Sub-millimetre Level Using Robotic Total Stations
Measurement of sub-millimetre-level deformations of structures in the presence of ambient temperature changes can be challenging. This paper describes the measurement of a structure moving due to temperature changes, using two ShapeAccelArray (SAA) instruments, and verified by a geodetic monitoring system. SAA is a geotechnical instrument often used for monitoring of displacements in soil. SAA uses micro-electromechanical system (MEMS) sensors to measure tilt in the gravity field. The geodetic monitoring system, which uses ALERT software, senses the displacements of targets relative to control points, using a robotic total station (RTS). The test setup consists of a central four-metre free-standing steel tube with other steel tubes welded to most of its length. The central tube is anchored in a concrete foundation. This composite “pole” is equipped with two SAAs as well as three geodetic prisms mounted on the top, in the middle, and in the foundation. The geodetic system uses multiple control targets mounted in concrete foundations of nearby buildings, and at the base of the pole. Long-term observations using two SAAs indicate that the pole is subject to deformations due to cyclical ambient temperature variations causing the pole to move by a few millimetres each day. In a multiple-day experiment, it was possible to track this movement using SAA as well as the RTS system. This paper presents data comparing the measurements of the two instruments and provides a good example of the detection of two-dimensional movements of seemingly rigid objects due to temperature changes.
Copyright (c) 2015 Tomas Beran, Lee Danisch, Adam Chrzanowski, Maciej Bazanowski
Deformation Measurements of Gabion Walls Using Image Based Modeling
The image based modeling finds use in applications where it is necessary to reconstruct the 3D surface of the observed object with a high level of detail. Previous experiments show relatively high variability of the results depending on the camera type used, the processing software, or the process evaluation. The authors tested the method of SFM (Structure from Motion) to determine the stability of gabion walls. The results of photogrammetric measurements were compared to precise geodetic point measurements.
Copyright (c) 2015 Marek Fraštia, Marián Marčiš, Ondrej Trhan
Denoising of Laser Scanning Data Using Wavelet
Regarding the terrestrial laser scanning accuracy, one of the main problems is the noise in measured distance which is necessary for the spatial coordinates´ determination. In this paper the technique of using the wavelet transformation for the reduction of the noise in the laser scanning data is described. This method of filtration is made in “post processing” and due to this fact any changes in the measuring procedure in the field shouldn´t be done. The creation of the regular matrix is needed to apply image processing. This matrix then makes the range image. In the paper real and simulated efficiency tests of wavelet transformation, the final summary and advantages or disadvantages of this method are introduced.
Copyright (c) 2015 Petr Jašek, Martin Štroner
Efficient plotting the functions with discontinuities based on combined sampling
This article presents a new algorithm for interval plotting of the function y = f(x) based on combined sampling. The proposed method synthesizes the uniform and adaptive sampling approaches and provides a more compact and efficient function representation. During the combined sampling, the polygonal approximation with a given threshold α between the adjacent segments is constructed. The automated detection and treatment of the discontinuities based on the LR criterion are involved. Two implementations, the recursive-based and stack-based, are introduced. Finally, several tests of the proposed algorithms for the different functions involving the discontinuities and several map projection graticules are presented. The proposed method may be used for more efficient sampling the curves (map projection graticules, contour lines, or buffers) in geoinformatics.
A GRASS GIS application for vertical sorting of sediments analysis in River Dynamics
The extreme versatility in different research fields of GRASS GIS is well known. A tool for the vertical sorting of sediments in river dynamics analysis is illustrated in this work. In particular, a GRASS GIS python module has been written which implements a forecasting sorting model by Blom&Parker (2006) to analyze river bed composition’s evolution in depth in terms of grainsize. The module takes a DEM and information relative to the bed load transport composition as input. It works in two different and consecutive phases: the first one uses the GRASS capabilities in analyzing geometrical features of the river bed along a chosen river reach, the second phase is the "numerical" one and implements the forecasting model itself, then executes statistical analyses and draws graphs, by the means of matplotlib library. Moreover, a specific procedure for the import of a laser scanner cloud of points is implemented, in case the raster DEM map is not available. At the moment, the module has been applied using flumes data from Saint Anthony Falls Laboratory (Minneapolis, MN) and some first results have been obtained, but the "testing" phase on other flume’s data is still in progress. Moreover the module has been written for GRASS 65 on a Ubuntu Linux machine, even if the debugging of a GRASS 64, Windowsversion, is also in progress. The final aim of this work is the application of the model on natural rivers, but there are still some drawbacks. First of all the need of a high resolution DEM in input, secondly the number and type of data in input (for example the bed load composition in volume fraction per each size considered) which is not easily obtainable, so the best solution is represented by testing the model on a well instrumented river reach to export in future the forecasting method to un-instrumented reaches.
Copyright (c) 2015 Annalisa Minelli, Gary Parker, Paolo Tacconi, Corrado Cencetti
Comparing speed of Web Map Service with GeoServer on ESRI Shapefile and PostGIS
There are several options how to configure Web Map Service using several map servers. GeoServer is one of most popular map servers nowadays. GeoServer is able to read data from several sources. Very popular data source is ESRI Shapefile. It is well documented and most of software for geodata processing is able to read and write data in this format. Another very popular data store is PostgreSQL/PostGIS object-relational database. Both data sources has advantages and disadvantages and user of GeoServer has to decide which one to use. The paper describes comparison of performance of GeoServer Web Map Service when reading data from ESRI Shapefile or from PostgreSQL/PostGIS database.
Open-source tool for automatic import of coded surveying data to multiple vector layers in GIS environment
This paper deals with a tool that enables import of the coded data in a single text file to more than one vector layers (including attribute tables), together with automatic drawing of line and polygon objects and with optional conversion to CAD. Python script v.in.survey is available as an add-on for open-source software GRASS GIS (GRASS Development Team). The paper describes a case study based on surveying at the archaeological mission at Tell-el Retaba (Egypt). Advantages of the tool (e.g. significant optimization of surveying work) and its limits (demands on keeping conventions for the points’ names coding) are discussed here as well. Possibilities of future development are suggested (e.g. generalization of points’ names coding or more complex attribute table creation).
Plotting the map projection graticule involving discontinuities based on combined sampling
This article presents new algorithm for interval plotting the projection graticule on the interval $\varOmega=\varOmega_{\varphi}\times\varOmega_{\lambda}$ based on the combined sampling technique. The proposed method synthesizes uniform and adaptive sampling approaches and treats discontinuities of the coordinate functions $F,G$. A full set of the projection constant values represented by the projection pole $K=[\varphi_{k},\lambda_{k}]$, two standard parallels $\varphi_{1},\varphi_{2}$ and the central meridian shift $\lambda_{0}^{\prime}$ are supported. In accordance with the discontinuity direction it utilizes a subdivision of the given latitude/longitude intervals $\varOmega_{\varphi}=[\underline{\varphi},\overline{\varphi}]$, $\varOmega_{\lambda}=[\underline{\lambda},\overline{\lambda}]$ to the set of disjoint subintervals $\varOmega_{k,\varphi}^{g},$$\varOmega_{k,\lambda}^{g}$ forming tiles without internal singularities, containing only "good" data; their parameters can be easily adjusted. Each graticule tile borders generated over $\varOmega_{k}^{g}=\varOmega_{k,\varphi}^{g}\times\varOmega_{k,\lambda}^{g}$ run along singularities. For combined sampling with the given threshold $\overline{\alpha}$ between adjacent segments of the polygonal approximation the recursive approach has been used; meridian/parallel offsets are $\Delta\varphi,\Delta\lambda$. Finally, several tests of the proposed algorithms are involved.
Developing web map application based on user centered design
User centred design is an approach in process of development any kind of human product where the main idea is to create a product for the end user. This article presents User centred design method in developing web mapping services. This method can be split into four main phases – user research, creation of concepts, developing with usability research and lunch of product. The article describes each part of this phase with an aim to provide guidelines for developers and primarily with an aim to improve the usability of web mapping services.
Integrating DROOLS and R software for intelligent map system
The paper describes intelligent map system that allows to check errors in map sheets or to help with a map sheet creation. The system is based on expert system DROOLS, ontology created in Protége and statistical software R. Prototype of the system should evaluate that this kind of integration is possible, so the system is not full of rules. The prototype is filled with twenty rules written in DRL language and with more than thirty items from the ontology. The paper should show how all of these components can be integrated together to allow such kind of a map sheet evaluation. The system is now used for selection of the best method for data classification. The selection is suggested by DROOLS system that uses R software to perform statistical tests of normality and uniformity.
Implementation of SQLite database support in program gama-local
The program gama-local is a part of GNU Gama project and allows adjustment of local geodetic networks. Before realization of this project the program gama-local supported only XML as an input. I designed and implemented support for the SQLite database and thanks to this extension gama-local can read input data from the SQLite database. This article is focused on the specifics of the use of callback functions in C++ using the native SQLite C/C++ Application Programming Interface. The article provides solution to safe calling of callback functions written in C++. Callback functions are called from C library and C library itself is used by C++ program. Provided solution combines several programing techniques which are described in detail, so this article can serve as a cookbook even for beginner programmers. This project was accomplished within my bachelor thesis.
Possibilities of contactless control of web map applications by sight
This paper assesses possibilities of a new approach of control map applications on the screen without locomotive system. There is a project about usability of Eye Tracking System in Geoinformatic and Cartographic fields at Department of Geoinformatics at Palacky University. The eye tracking system is a device for measuring eye/gaze positions and eye/gaze movement ("where we are looking"). There is a number of methods and outputs, but the most common are "heat-maps" of intensity and/or time. Just this method was used in the first part, where was analyzed the number of common web map portals, especially distribution of their tools and functions on the screen. The aim of research is to localize by heat-maps the best distribution of control tools for movement with map (function "pan"). It can analyze how sensitive are people on perception of control tools in different web pages and platforms. It is a great experience to compare accurate survey data with personal interpretation and knowledge. Based on these results is the next step – design of "control tools" which is command by eye-tracking device. There has been elected rectangle areas located on the edge of map (AOI – areas of interest), with special function which have defined some time delay. When user localizes one of these areas the map automatically moves to the way on which edge is localized on, and time delay prevents accidental movement. The technology for recording the eye movements on the screen offers this option because if you properly define the layout and function controls of the map, you need only connect these two systems. At this moment, there is a technical constrain. The solution of movement control is based on data transmission between eye-tracking-device-output and converter in real-time. Just real-time transfer is not supported in every case of SMI (SensoMotoric Instruments company) devices. More precisely it is the problem of money, because eye-tracking device and every upgrade is very expensive. This constrains and their solutions are also discussed in paper. Main aim of the project is to design (both economically and technologically), optimal way how to record and convert eye-movement in a program with sophisticated control of movements.
Designing a New Raster Sub-System for GRASS-7
The paper deals with a design of a new raster sub-system intended for modern GIS systems open for client and server operation, database connection and strong application interface (API). Motivation for such a design comes from the current state of API working in GRASS 6. If found attractive, the here presented design and its implementation (referred as RG7) may be integrated to the future new generation of the GRASS Geographical Information System version 7-8. The paper describes in details the concept of raster tiling, computer storage of rasters and basic raster access procedures. Finally, the paper gives a simple benchmarking experiment of random read access to raster files imported from the Spearfish dataset. The experiment compares the early implementation of RG7 with the current implementation of rasters in GRASS 6. As the result, the experiment shows the RG7 to be significantly faster than GRASS in random read access to large raster files.
Klet Observatory – European Contribution to Detecting and Tracking of Near Earth Objects
Near Earth Object (NEO) research is an expanding field of astronomy. Is is important for solar system science and also for protecting human society from asteroid and comet hazard. A near-Earth object (NEO) can be defined as an asteroid or comet that has a possibility of making an approach to the Earth, or possibly even collide with it. The discovery rate of current NEO surveys reflects progressive improvement in a number of technical areas. An integral part of NEO discovery is astrometric follow-up fundamental for precise orbit computation and for the reasonable judging of future close encounters with the Earth including possible impact solutions. A wide international cooperation is fundamental for NEO research. The Klet Observatory (South Bohemia, Czech Republic) is aimed especially at the confirmation, early follow-up, long-arc follow-up and recovery of Near Earth Objects. It ranks among the world´s most prolific professional NEO follow-up programmes. The first NEO follow-up programme started at Klet in 1993 using 0.57-reflector equipped with a small CCD camera. A fundamental upgrade was made in 2002 when the 1.06-m KLENOT telescope was put into regular operation. The KLENOT Telescope is the largest telescope in Europe used exclusively for observations of minor planets (asteroids) and comets and full observing time is dedicated to the KLENOT team. Equipment, technology, software, observing strategy and results of both the Klet Observatory NEO Project between 1993-2010 and the first phase of the KLENOT Project from March 2002 to September 2008 are presented. They consist of thousands of precise astrometric measurements of Near Earth Objects and also three newly discovered Near Earth Asteroids. Klet Observatory NEO activities as well as our future plans fully reflect international strategies and cooperation in the field of NEO studies.
The Virtual 3D Reconstruction of the East Pediment of the Temple of Zeus at Olympia – Presentation of an Interactive CD-ROM
The paper gives an overview of a two-years project concerning a major monument of ancient Greek art and presents the interactive, bilingual (English/Hungarian) CD-ROM, which is intended to summarize and visualize its final results. The presented project approaches a century-old controversy in a new way by producing a virtual 3D reconstruction of a monumental marble group. Digital models of the statues were produced by scanning the original fragments and by reconstructing them virtually. The virtual model of the pediment surrounding the sculptures was prepared on the basis of the latest architectural studies and afterwards the reconstructed models were inserted in this frame, in order to test the technical feasibility and aesthetic effects the four possible arrangements. The resulting models enable easy and very instructive experimentation, which would be otherwise impossible with the originals and/or very expensive and not very practicable with traditional tools (e.g. real-size plaster models). The complete model can effectively be used to verify the results of earlier or more recent reconstructions presented only in simple drawings. In addition, the 3D models of the individual fragments can be used for further research and for visualization. The documentary CD-ROM presenting the full background, the methods and the conclusions of the project contains beside a comprehensive text various kinds of supporting documents (images, 3D models, papers, broadcasts, audiovisual material). It is addressed to a mixed audience: a picture gallery, a short documentary movie some other attachments including a selected bibliography is intended for the general public, but scholarly publications, presentations on related problems are also included for specialists interested in certain details.
Copyright (c) 2015 András PATAY-HORVÁTH Patay-Horváth
Comparison of orthometric heights obtained from the combination of GPS/Levelling survey method with that obtained from Lidar, Srtm, and Astergdem data is an area of research which is of great interest to Geomaticians. This area of research makes possible the discovery of other suitable methods of determining orthometric height which can be selected for use depending on the region, extent and nature of the terrain where the project is to be executed. The X, Y, Z coordinates and the geoidal heights for all the existing controls within university of Lagos were determined using the GPS/ Levelling survey method, the required orthometric height (H) was then obtained as the differences between ellipsoidal and geoidal heights. Extracting orthometric heights for the X and Y coordinates of observed control points overlaid on each of Lidar, Srtm and Astergdem required the use of spatial analysis tool in an arc map environment. From the profile plot (Figure 3.5) of all the orthometric heights, the heights relationship was easy established. From the descriptive statistics test (Table 3.4), the one way ANOVAs test at 1% and 5% level of significance (Table 3.8), the number of points in other methods whose orthometric height is closed to that of Levelling/GPS method (Table 3.7) and correlation test on the various orthometric heights obtained (Table 3.5) it is obvious that all the applied methods operates at different spatial resolutions, of all the four methods, GPS/Levelling method was the most reliable and most accurate method followed by lidar method, then by astergdem method and Srtm has the least. In a nutshell, Orthometric heights generated by method of Lidar are very close to that generated by GPS/Levelling method at several stations, thus method of Lidar was considered as the most suitable alternative to GPS/Levelling method, whenever the use of later method cannot be easily accomplished.
Copyright (c) 2018 Olusola Gabriel Omogunloye
Modeling Malaria Prevalence Rate in Lagos State Using Multivariate Environmental Variations
The aim of this research is to establish the significant effect of environmental factors on malaria prevalence rate within the Local Government Areas of Lagos State. The methodology used was to carry out a statistical analysis of these various environmental factors with the malaria prevalence cases that was recorded in Lagos State using a 5 years data from 2009-2013 of malaria prevalence cases recorded with environmental data for the same time frame, and to further use GIS to show the various Local Government Areas with high severe malaria cases as well as low malaria cases. The result obtained from this analysis shows a significant relationship between the malaria prevalence cases and environmental factors of rainfall, temperature and relative humidity, this helped in developing a predictive model. The outcome from this research work can help the government, Lagos State Ministry of Health and donor agencies both local and international see the Local Government Areas within the state that are most vulnerable to malaria epidemic, and further aid them in policy formation, planning and strategy implementation.
Deriving Hydrological Response Units (HRUs) using a Web Processing Service implementation based on GRASS GIS
QGIS releases equal to or newer than 0.7 can easily connected to GRASS GIS by means of a toolbox that provides a wide range of standard GRASS modules you can launch – albeit only on data coming from GRASS. This QGIS plugin is expandable through XML configurations describing the assignment of options and inputs for a certain module. But how about embedding a precise workflow where the several processes don’t consist of a single GRASS module by force? Especially for a sequence of dependent tasks it makes sense to merge relevant GRASS functionality into an own and encapsulated QGIS extension. Its architecture and development is tested and combined with the Web Processing Service (WPS) for remote execution using the concept of hydrological response units (HRUs) as an example. The results of this assay may be suitable for discussing and planning other wizard-like geoprocessing plugins in QGIS that also should make use of an additional GRASS server.
Projekt OpenStreetMap z pohledu geoinformatika
This article discusses conditions suitable for creation of open-licensed geographic data, distinguishes different levels of opennes. It focuses the OpenStreetMap community project, which has the aim to create and provide free geographic data. This paper gives a brief insight to the project, presents its key features and its history. Práce pojednává o podmínkách vhodných pro vytváření geodat se svobodnou licencí, rozlišuje různou úroveň jejich otevřenosti. Dále se zaměřuje na komunitní projekt OpenStreetMap, který vytváří a udržuje svobodná geografická data. Poskytuje prvotní náhled na projekt, seznamuje s jeho klíčovými vlastnostmi a vývojem.
ISO 19115 for GeoWeb services orchestration
The paper describes theoretical and practical possibilities of ISO 19115 standard in a process of generating dynamic GeoWeb services orchestras. There are several ways how to instantiate orchestras according to current state of services and user needs, some of them are briefly described in the paper. The most flexible way is based on metadata that describe geodata used by services. The most common standard used for geodata metadata in the EU is ISO 19115. The paper should describe if the standard is able (without extensions) to hold enough information for orchestration purposes. The paper defines minimal set of metadata items named ”ISO 19115 Orchestration Minimal” that must be available for geodata evaluation in a process of orchestration. A second part of the article will be probably less optimistic. It should describe how are (or were, or are planned to be) ISO 19115 possibilities used for metadata creation nowadays in the Czech Republic. This part is based on analyses of ISO 19115 core, MIDAS system, Dublin Core and INSPIRE metadata IR.
Moebius: An interface to web map services
Our article presents a concept of a geospatial search engine based on a Web Map Service (WMS) compliant virtual mapserver. This virtual mapserver is able to index mapservers based on the WMS standard and create an unified interface to all shared map layers. Our presented approach also allows to search the map layers within the virtual mapserver and process the results directly in GIS tools.
Copyright (c) 2015 David Procházka, Jana Procházková
Graphical user interface is an important element of today software. Discussion on design aspects of toolbar icons is presented. Three concepts related to GIS applications are proposed. Preliminary icon set gis-0.1 oriented to usability and simplicity is outlined.
Součástí výzkumného projektu "Orchestrace služeb pro GeoWeb" GA 205/07/0797 řešeného na Institutu geoinformatiky VŠB-TU Ostrava, zabývajícího se možností orchestrace webových služeb z oblasti GIS a ověřením praktických možností dostupných jazyků pro popis a plánování obchodních procesů je i část zabývající se návrhem grafického uživatelského rozhraní, které by umožňovalo uživatelům na různých úrovních funkcionality pracovat s těmito orchestry služeb. Jaká je míra funkcionality, kterou jednotliví uživatelé požadují? Má jim být umožněno vyhledávat orchestry, spouštět je, parametrizovat, upravovat, či dokonce navrhovat? Na tyto otázky se snaží odpovědět následující řádky, ve kterých jsou shrnuty základní údaje o orchestraci v oblasti GeoWebu, analýza a popis charakteristik jednotlivých uživatelů i návrh samotného grafického rozhraní koncového uživatele a popis komponent, které by měl být v tomto rozhraní pro práci s orchestry k dispozici.
Change Detection with GRASS GIS – Comparison of images taken by different sensors
Images of American military reconnaissance satellites of the Sixties (CORONA) in combination with modern sensors (SPOT, QuickBird) were used for detection of changes in land use. The pilot area was located about 40 km northwest of Yemen’s capital Sana’a and covered approximately 100 km2 . To produce comparable layers from images of distinctly different sources, the moving window technique was applied, using the diversity parameter. The resulting difference layers reveal plausible and interpretable change patterns, particularly in areas where urban sprawl occurs. The comparison of CORONA images with images taken by modern sensors proved to be an additional tool to visualize and quantify major changes in land use. The results should serve as additional basic data eg. in regional planning. The computation sequence was executed in GRASS GIS.
Copyright (c) 2015 Michael Fuchs, Rainer Hoffmann, Friedhelm Schwonke
The importance of computational geometry for digital cartography
This paper describes the use of computational geometry concepts in the digital cartography. It presents an importance of 2D geometric structures, geometric operations and procedures for automated or semi automated simplification process. This article is focused on automated building simplification procedures, some techniques are illustrated and discussed. Concrete examples with the requirements to the lowest time complexity, emphasis on the smallest area enclosing rectangle, convex hull or self intersection procedures, are given. Presented results illustrate the relationship of digital cartography and computational geometry.
GAL Framework – Current State of the Project
The GAL (GIS Abstraction Layer) Framework is a component-architecture-oriented1 remote procedure call (RPC) library with implementations of GIS-related subsystems communicating using the library and a set of demonstrational and testing tools utilizing that services. It doesn’t aim to be a full-featured solution for GIS application construction but a proposal for possible incremental GRASS GIS2 modernization. This article summarizes current state of the project, it’s history, application and potential and also presents options for further advancement and areas of possible participation. Only a concern of other developers or users and the time may transform this idea into something practically usable.
Copyright (c) 2015 Radek Bartoň, Martin Hrubý
Accurate Measurement of the Riverbed Model for Deformation Analysis using Laser Scanning Technology
This paper presents an interesting application of the riverbed model shape and deformations monitoring using laser scanning technology and accurate local micro-network. The most interesting fact about this application is very high accuracy demand on deformation determination (maximum permissible error is only 2 mm) within quite large object (the size of the riverbed model is about 100 meters). Up to now, mechanical calipers in the selected profiles were used to detect the changes. This manual approach is very laborious and time-consuming and the gathered data resolution and accuracy is often not sufficient. The suggested solution contains two main parts. The first part deals with construction of highly accurate local micro-network for laser scanning needs (maximum required standard deviation in any coordinate is lower than 0.4 mm) and the second part deals with actual laser scanning and data processing. Design, measurement and processing of the experiment was conducted for the needs of the research project “Improvement of navigation conditions on the Elbe between Ústí nad Labem - state border CR / FRG - Navigation Step Děčín”. The main goal of this project is design and realization of the river regulation to improve the navigation conditions. The key benefit of using river model is the possibility to easily simulate various catastrophic scenarios (various degrees of the floods) and their impacts on riverbed changes.
Copyright (c) 2018 Martin Štroner, Rudolf Urban, Tomáš Křemen, Bronislav Koska
GeoEasy an open source project for surveying calculations
The development of the GeoEasy program started in 1997. Twenty years later in 2017 it became free software under GPL license, version 3.0.0 is freely available for everybody. The core development of GeoEasy is made on Linux operating system, using Tcl/Tk script language, thanks to the Tcl/Tk ports to other operating systems, the program can be run on Linux, Windows, Android and OSX machines. Objectives of the development are to create user friendly graphical user interface (GUI) for surveying calculations in a modular structure with flexible, open connections to other programs. Both educational and professional usages are supported.
Geodetic work at the archaeological site Tell el-Retaba
The paper summarizes the geodetic contribution for the Slovak team within the joint Polish-Slovak archaeological mission at Tell el-Retaba in Egypt. Surveying work at archaeological excavations is usually influenced by somewhat specific subject of study and extreme conditions, especially at the missions in the developing countries. The case study describes spatial data development according to the archaeological conventions in order to document spatial relationships between the objects in excavated trenches. The long-term sustainability of surveying work at the site has been ensured by detailed metadata recording. Except the trench mapping, Digital Elevation Model has been calculated for the study area and for the north-eastern part of the site, with promising preliminary results for further detection and modelling of archaeological structures. In general, topographic mapping together with modern technologies like Photogrammetry, Satellite Imagery, and Remote Sensing provide valuable data sources for spatial and statistical modelling of the sites; and the results offer a different perspective for the archaeological research.