Geoinformation Issues Vol. 2, No 1, 2010
Jaakko Mäkinen, Marcin Sękowski, Jan Kryński
The use of the A10-020 Gravimeter for the Modernizationof the Finnish First Order Gravity Network
DOI: 10.34867/gi.2010.1
Abstract. The A10 is the first absolute gravimeter that allows the rapid determination of gravity with high accuracy in field conditions. In many applications, an absolute gravity survey with the A10 thus becomes highly competitive with traditional relative gravity surveys, in terms of both efficiency and accuracy. In particular, it is very efficient in the modernization of gravity control and high precision gravity survey required in modern gravity networks.
In 2008 the Institute of Geodesy and Cartography received the outdoor free-fall gravimeter A10 No 020. Time series of gravity taken with it since September 2008 at the Borowa Gora Geodetic-Geophysical Observatory in Poland show that the A10-020 provides high quality measurements in laboratory as well as in fi eld conditions.
In 2009–2010 the A10-020 gravimeter was used for the re-measurement of the Finnish First Order Gravity Network. Altogether 51 fi eld sites were occupied, with a repeatability better than 4 μGal. For control, 9 Finnish absolute gravity stations were occupied with the A10-020 altogether 25 times. From preliminary computations, the offset of the A10-020 to the FG5-221 of the Finnish Geodetic Institute was negligible and the RMS difference was 3 μGal.
The polarization–stabilized laser and the rubidium frequency standard of the A10-020 were calibrated before and after the surveys at the Finnish National Metrology Institute MIKES to ensure the metrological quality of the measurements.
The results obtained confi rm the applicability of the A10 absolute gravimeter to the modernization of gravity control networks.
Stanisław Lewiński, Zbigniew Bochenek, Konrad Turlej
Application of object-oriented method for classification of VHR satellite images using rule-based approach and texture measures
DOI: 10.34867/gi.2010.2
Abstract. New approach for classification of high-resolution satellite images is presented in the article. That approach has been developed at the Institute of Geodesy and Cartography, Warsaw, within the Geoland 2 project – SATChMo Core Mapping Service. Classifi cation algorithm, aimed at recognition of generic land cover categories, has been elaborated using the object-oriented approach. Its functionality was tested on the basis of KOMPSAT-2 satellite images, recorded in four multispectral bands (4 m ground resolution) and in panchromatic mode (1 m ground resolution). The structure of the algorithm resembles decision tree and consists of a sequence of processes. The main assumption of the presented approach is to divide image contents into objects characterized by high and low texture measures. The texture measures are generated on the basis of a panchromatic image transformed by Sigma filters. Objects belonging to the so-called high texture are classified at fi rst steps. In the following steps the classification of the remaining objects takes place. Applying parametric criteria of recognition at the fi rst group of objects four generic land cover classes are classified: forests, sparse woody vegetation, urban / artificial areas and bare ground. Non-classified areas are automatically assigned to the second group of objects, which contains water and agricultural land. In the course of classification process a few segmentations are performed, which are dedicated to particular land cover categories. Classified objects, smaller than 0.25 ha are removed in the process of generalization.
Albina Mościcka, Marek Marzec
Interactive map of movable cultural heritage
DOI: 10.34867/gi.2010.3
Abstract. The paper presents the results of a research project connected with using Geographic Information System (GIS) – as a technology and as a tool – to integrate different digital archival collections, present their content in one space and provide on-line access to them from one common level – from an on-line map.
Digital archives contain a lot of movable heritage which content has no simple relation to geographic space: manuscripts or old prints can be created in one place, they can describe other places and now they can be stored still in another place. Moreover, each archival object could have been stored in many different places in the past.
Presented paper propose the method of creating movable heritage map, based on all geographical places connected with digital collections. The starting point of the study was the international standards for describing digital collections. They provide metadata which are the source of spatial information about archival objects and about spatial, temporal, typological and semantic relations between them. All these aspects were integrated in the GIS and presented as the prototype of an on-line interactive map. Proposed
solutions as well as practical applications of the map are presented in the paper.
Adam Linsenbarth, Albina Mościcka
The infl uence of the Bible geographic objects peculiarities on the concept of the spatiotemporal geoinformation system
DOI: 10.34867/gi.2010.4
Abstract. The article describes the infl uence of the Bible geographic object peculiarities on the spatiotemporal geoinformation system of the Bible events. In the proposed concept of this system the special attention was concentrated to the Bible geographic objects and interrelations between the names of these objects and their location in the geospace. In the Bible, both in the Old and New Testament, there are hundreds of geographical names, but the selection of these names from the Bible text is not so easy. The same names are applied for the persons and geographic objects. The next problem which arises is the classifi cation of the geographical object, because in several cases the same name is used for the towns, mountains, hills, valleys etc. Also very serious problem is related to the time-changes of the names. The interrelation between the object name and its location is also complicated. The geographic object of this same name is located in various places which should be properly correlated with the Bible text.
Above mentioned peculiarities of Bible geographic objects infl uenced the concept of the proposed system which consists of three databases: reference, geographic object, and subject/thematic. The crucial component of this system is proper architecture of the geographic object database. In the paper very detailed description of this database is presented.
The interrelation between the databases allows to the Bible readers to connect the Bible text with the geography of the terrain on which the Bible events occurred and additionally to have access to the other geographical and historical information related to the geographic objects.
Konrad Turlej, Maciej Bartold, Stanisław Lewiński
Analysis of extent and effects caused by the flood wave in May and June 2010 in the Vistula and Odra River Valleys
DOI: 10.34867/gi.2010.5
Abstract. In May and June 2010 a flood occurred in Poland, which was the result of intensive rainfalls in the upper sections of the Vistula and Odra Rivers. Medium-resolution TERRA-MODIS satellite images were used for analysis of the extent of the flood wave. Images taken on 6 June for the Vistula River Valley and on 9 June for the Odra River Valley were selected from a generally accessible database. The size of flooded areas was delineated using an object-oriented classifi cation methods in the eCognition software
environment. Statistical analysis of classifi cation results was performed at the municipality level, by comparing the classifi cation with Corine Land Cover 2006 database. During the discussed flood, areas in 184 municipalities along the Vistula River and in 120 municipalities along the Odra River were flooded. The most extensive flooding occurred in Slonsk Municipality in the Odra River Valley, where 4055 hectares were flooded. In total, the Vistula waters flooded 4.01% of the area of municipalities located within the Vistula
River Valley, and 3.29% of the area of Odra municipalities were flooded by the Odra River waters.