Journal•ISSN: 1217-8977
Acta Geodaetica Et Geophysica Hungarica
Akadémiai Kiadó
About: Acta Geodaetica Et Geophysica Hungarica is an academic journal. The journal publishes majorly in the area(s): Global Positioning System & TEC. Over the lifetime, 911 publications have been published receiving 4655 citations.
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TL;DR: In this work GPS/GLONASS systems are combined for single point positioning and their performance are assessed for different configurations, and a pseudo-measurement is introduced to compensate for the addition of an additional unknown.
Abstract: In signal-degraded environments such as urban canyons and mountainous area, many GNSS signals are either blocked or strongly degraded by natural and artificial obstacles. In such scenarios standalone GPS is often unable to guarantee a continuous and accurate positioning due to lack (or the poor quality) of signals. The combination of different GNSSs could be a suitable approach to fill this gap, because the multi-constellation system guarantees an improved satellite availability compared to standalone GPS, thus providing enhanced accuracy, continuity and integrity of the positioning. The present GNSSs are GPS, GLONASS, Galileo and Beidou, but the latter two are still in the development phase. In this work GPS/GLONASS systems are combined for single point positioning and their performance are assessed for different configurations. Using GPS/GLONASS multi-constellation implies the addition of an additional unknown, i.e. the intersystem time scale offset, which requires a sacrifice of one measurement. Since the intersystem offset is quasi-constant over a short period, a pseudo-measurement can be introduced to compensate the sacrifice. The benefit after adding a pseudo-measurement has been demonstrated in a vehicular test.
89 citations
TL;DR: In this paper, the authors present procedures which have been used to construct a map in cells on the electrical resistivity distribution in Europe at least till to the asthenosphere, which is the basis of the calculation of the induction risk endangering the electric network and communication systems.
Abstract: In connection with the EURISGIC WP2 project the authors present those procedures which have been used to construct a map in cells on the electrical resistivity distribution in Europe at least till to the asthenosphere. The data are based on the deep magnetotelluric soundings published in the international literature. This map is the basis of the calculation of the induction risk endangering the electric network and communication systems.
51 citations
TL;DR: The historical earthquakes that have been felt in Egypt were compiled from Arabic documents and earlier earthquake catalogues as mentioned in this paper, and about 83 earthquakes were found during the period from 2200BC to 1899AD.
Abstract: The historical earthquakes that have been felt in Egypt were compiled from Arabic documents and earlier earthquake catalogues. About 83 earthquakes were found during the period from 2200BC to 1899AD.
50 citations
TL;DR: An edge detector method for the enhancement of potential field anomalies, based on the logistic function of the total horizontal gradient, which is tested on synthetic data calculated using 3 models, and also on real magnetic and gravity data from Vietnam to demonstrate that the method is a useful tool for the qualitative interpretation of possible field data.
Abstract: Locating the edges of anomalous bodies provides a fundamental tool in the geologic interpretation of potential field data. This paper compares the effectiveness of the commonly used edge detection methods such as the total horizontal gradient, analytic signal, tilt angle, theta map and their modified versions in terms of their accuracy on the determination of edges of source bodies. This paper also introduces an edge detector method for the enhancement of potential field anomalies, which is based on the logistic function of the total horizontal gradient. The new method is tested on synthetic data calculated using 3 models, and also on real magnetic and gravity data from Vietnam. The effectiveness of the method is evaluated by comparing the results with those of other popular methods. These results demonstrate that the method is a useful tool for the qualitative interpretation of potential field data.
47 citations
TL;DR: The First Military Survey maps of the Habsburg Monarchy, produced between 1763 and 1787, were used as study data and the rugged Julian Alps of the Triglav National Park in Slovenia were employed as the study area.
Abstract: Various spatial data sets of high quality and homogeneity allow a higher level of multidisciplinary research. The study is aimed at providing a clearer understanding of the technical and semantic aspects of the quality of historical maps, especially with respect to positional errors, through the georeferencing process. Georeferencing the system of historical map sheets with high precision over a large area is not easily incorporated into the less complicated standardised process. Significant problems may occur in rough mountainous regions, especially as many of the areas were not accessed at that time and therefore not surveyed. The standard process of georeferencing comprises mosaicking of singular map sheets to a seamless map, referencing with identical points, and applying an appropriate transformation method. The quality of georeferenced maps is assessed with statistical and visual parameters. The enhanced process additionally integrates descriptive (textual) information about the mapping processes, derivative georeferenced data sets as land use analysis, and Monte Carlo simulations. This approach allows a more detailed understanding of the quality and consequently improves a georeferencing process for any historical data sets. The First Military Survey maps of the Habsburg Monarchy (Josephine survey), produced between 1763 and 1787, were used as study data and the rugged Julian Alps of the Triglav National Park in Slovenia were employed as the study area.
46 citations