Filtry
wszystkich: 226
Wyniki wyszukiwania dla: SATELLITE MECHANISM
-
Designing of Track Axis Alignment with the Use of Satellite Measurements and Particle Swarm Optimization
PublikacjaDesigning of the track’s alignment is a key issue from the point of view of maintaining of proper geometries. The paper presents a design method for sections of railway line located in the horizontal arch. The method is adapted to the technique of mobile satellite measurements. The general principles of this measurement method have been described in the article. A project's solution has been presented using mathematical notation...
-
A Method for Determination and Compensation of a Cant Influence in a Track Centerline Identification Using GNSS Methods and Inertial Measurement
PublikacjaAt present, the problem of rail routes reconstruction in a global reference system is increasingly important. This issue is called Absolute Track Geometry, and its essence is the determination of the axis of railway tracks in the form of Cartesian coordinates of a global or local coordinate system. To obtain such a representation of the track centerline, the measurement methods are developed in many countries mostly by the using...
-
The possibility of estimating the height of the ionospheric inhomogeneities based on TEC variations maps obtained from dense GPS network
PublikacjaA state of the ionosphere can be effectively studied using electromagnetic signals received from global navigation satellite systems (GNSS). Utilization of the dual frequency observations allows estimating values of the total electron content (TEC). They can be used for a number of scientific studies such as detection and monitoring of traveling ionospheric disturbances or plasma bubbles. Moreover, maps of TEC variations allow...
-
Mobile satellite measurements on the Pomeranian Metropolitan Railway
PublikacjaThis paper presents the process of organization and execution of the mobile satellite measurements conducted on the tracks of the Pomeranian Metropolitan Railway before officially entry the line into operation. These measurements allowed for the accurate identification of the actual geometric shape of the line. In the paper the issues of both design and construction phase of this railway line has been described. Moreover, the geodetic...
-
THE APPLICATION EFFECTS OF CONTINUOUS SATELLITE MEASUREMENTS OF RAILWAY LINES
PublikacjaThe paper presents results of satel lite surveying of the railway's rout es, which have been conducted just after starting in Poland (in 2008) the Active Geodesy Network ASG-EU POS. Afterwards it was possible to effectively utilize the GNSS survey ing results for the inventory of the (exploring) railways in service. Already at the beginning of 2009, the research team from Gdansk University of Technology and Naval Academy in Gdynia,...
-
Research project BRIK: development of an innovative method for determining the precise trajectory of a railway vehicle
PublikacjaIn the paper the essential assumptions regarding a research project implemented by a consortium of Gdansk University of Technology and Gdynia Maritime University are presented. The project has been commissioned by National Center of Research and Development with cooperation with Polish Railways (PKP Polskie Linie Kolejowe S.A.). The project is focused in implementation of modern measurement techniques using Global Navigation Positioning...
-
Spatiotemporal Assessment of Satellite Image Time Series for Land Cover Classification Using Deep Learning Techniques: A Case Study of Reunion Island, France
PublikacjaCurrent Earth observation systems generate massive amounts of satellite image time series to keep track of geographical areas over time to monitor and identify environmental and climate change. Efficiently analyzing such data remains an unresolved issue in remote sensing. In classifying land cover, utilizing SITS rather than one image might benefit differentiating across classes because of their varied temporal patterns. The aim...
-
Nauka w świecie cyfrowym okiem młodego inżyniera - nawigacja mobilna w miastach
PublikacjaDynamiczny rozwój technologii ICT i miniaturyzacja komponentów elektronicznych doprowadziły do sytuacji, w której znaczna część światowego społeczeństwa korzysta z urządzeń mobilnych. Dzięki powszechnemu dostępowi do smartfonów każdy użytkownik może w prosty sposób sprawdzić swoje położenie, niezależnie od tego, gdzie w danej chwili się znajduje. Ponadto sami operatorzy sieci komórkowych oraz dostawcy szeregu serwisów korzystają...
-
Communication Networks in the Service of the Environmental Monitoring
PublikacjaIn the paper selected issues relating to communication networks in the services of the environmental monitoring (EM) have been described. It is divided into three main parts: introduction, wire and wireless networks. At the beginning of the basic definitions were explained. The wire part focuses on a plain old telephone service (POTS), an integrated services digital network (ISDN), a digital subscriber line (DSL) and a fiber-optic...
-
Application of Web-GIS and Geovisual Analytics to Monitoring of Seabed Evolution in South Baltic Sea Coastal Areas
PublikacjaRegular surveys of coastal zone seabed deliver important information about geomorphologic processes such as silting of waterways. The recent introduction of the Sentinel series of sensors has allowed for the use of satellite sensing for shallow bathymetry morphology monitoring. In this context, this article presents a dedicated Geographic Information System for Baltic Sea shallow water depth monitoring on the basis of Sentinel-2...
-
GeoSPAR Project. Validation and selection methods of geoinformation analysis using GIS for ranking and forecasting of terrorist threats and criminal events
PublikacjaThe paper presents the description of work activities which have already been done within the first two stages – WorkPackage 1 and WorkPackage 2 - of the GeoSPAR Project. In such a context the general conceptual design of the GIS system and associate web service was presented and analysed. In addition, the operational and technical requirements for the GeoSPAR system have been specified and discussed; with special emphasis on system...
-
Identification of Shift in Sowing and Harvesting Dates of Rice Crop (L. Oryza sativa) through Remote Sensing Techniques: A Case Study of Larkana District
PublikacjaThe present study aimed to determine the impact of climate variability on rice crops in terms of sowing and harvesting dates and crop period. The identification of sowing and harvesting dates were spotted by mask identification, variations in land surface temperature (LST) on a temporal scale in the respective months, and a field-level social inquiry. The study was conducted during a time period (1994–2017), in which geo-referenced...
-
Spatio-temporal filtering for determination of common mode error in regional GNSS networks
PublikacjaThe spatial correlation between different stations for individual components in the regional GNSS networks seems to be significant. The mismodelling in satellite orbits, the Earth orientation parameters (EOP), largescale atmospheric effects or satellite antenna phase centre corrections can all cause the regionally correlated errors. This kind of GPS time series errors are referred to as common mode errors (CMEs). They are usually...
-
DETERMINATION OF THE CITY CENTRE. STUDY FOR THE TROJMIASTO AGGLOMERATION
PublikacjaDetermination of the centre of the city or agglomeration or generally the geographic area is a task which is often undertaken as part of the promotional actions realized by local authorities or directly by inhabitants. Nowadays, especially due to the development and availability of positioning technology and satellite imaging, this job is undertaken within the framework of general didactic tasks and group projects during the study...
-
Problemy pozycjonowania satelitarnego w aglomeracjach miejskich
PublikacjaW artykule przedstawiono rozważania teoretyczne i wyniki eksperymentów, których celem było zasygnalizowanie pewnych problemów związanych z zastosowaniem GNSS (z ang.: Global Navigation Satellite Systems - Globalne Satelitarne Systemy Nawigacyjne) w aglomeracjach miejskich. W pierwszej części artykułu przedstawiono rozważania dotyczące potencjalnych problemów związanych z wyznaczaniem współrzędnych pozycji w środowisku występowania...
-
Analysis of free‐air anomalies on the seaway of the Gulf of Gdańsk. A case study
PublikacjaIn this paper, we present an attempt to determine the accuracy of shipborne gravimetry for the needs of geoid determination. The shipborne gravity campaign, described in this article, is the beginning of a series of gravimetry measurements in the Polish Exclusive Economy Zone. The campaign was conducted in the area where the accuracy of geoid determination is crucial for the safety of navigation on numerous intersecting ships routes....
-
Identifying the Effects of Selected Road and Roadside Parameters on Road Safety Using Geodetic Techniques
PublikacjaThe paper will present techniques that can be used to obtain data on road alignment and profile including the roadside. In-the-field and simulation studies have helped to develop mathematical models that integrate vehicle position data. The experiments were conducted in a virtual environment using the software ArcGIS that reflects the actual roadside conditions. The site tests were made using a purpose-built device which integrates...
-
Mobile indicators in GIS and GPS positioning accuracy in cities
PublikacjaThe publication describes the possible use of tele-geoprocessing as a synergy of modern IT solutions, telecommunications and GIS algorithms. The paper presents a possibility of urban traffic monitoring with the use of mobile GIS indicators of dedicated monitoring system designed for taxi corporation. The system is based on a stationary and mobile software package. The optimal and minimal assumptions for the monitoring of urban...
-
Tryton Supercomputer Capabilities for Analysis of Massive Data Streams
PublikacjaThe recently deployed supercomputer Tryton, located in the Academic Computer Center of Gdansk University of Technology, provides great means for massive parallel processing. Moreover, the status of the Center as one of the main network nodes in the PIONIER network enables the fast and reliable transfer of data produced by miscellaneous devices scattered in the area of the whole country. The typical examples of such data are streams...
-
New satellite pumps
PublikacjaStosowanie Maszyn company from Katowice was initiator and originator of newest original high pressure satellite pumps series of types PSM. Construction solution, research and development of these pumps have been conducted by Team of Hydraulics and Pneumatics of Gdansk University of Technology in cooperation with this company within the confines of research project nr R0300103 (source of funds: Ministry of Science and Higher Education)....
-
Analysis of the objects images on the sea using Dempster-Shafer Theory
PublikacjaThe paper presents the concept of using aerial and satellite imagery or images coming from the marine radar to identify and track vessels at sea. The acquired data were subjected to a highly advanced image analysis. The development of remote sensing techniques allows to gain a huge amount of data. These data are useful information source however usually we have to use different data mining methods to gain interested information....
-
A Circular Waveguide Dual-Mode Filter With Improved Out-of-Band Performance for Satellite Communication Systems
PublikacjaThis letter presents a novel design for a 3-D-printed circular waveguide dual-mode (CWDM) filter with a modified cavity shape. The modification leads to a wide spurious-free stopband, which is highly desirable for channel separation in waveguide contiguous output multiplexers (OMUXs) in satellite communication systems. The new resonant cavity design is a result of applying shape deformation to a basic circular cavity in order to...
-
High-Gain Compact Circularly Polarized X-Band Superstrate Antenna for CubeSat Applications
PublikacjaIn this letter, a concept of high-gain circularly polarized X-band antenna employing a partially reflecting surface (PRS) has been presented. In the initial antenna analysis, the influence of parasitic elements size in the PRS structure on antenna radiation pattern parameters has been investigated and the optimal arrangement of the elements has been identified. The proposed antenna provides wide bandwidth of return loss above 10...
-
Analytical design method of reverse curves
PublikacjaThe paper deals with a new approach relating to the design of the region of railway track direction alteration adapted to Mobile Satellite Measurements technique. The method may be particularly useful in situations when both the straights of the route directions cannot be connected in an elementary way using a circular arc with transition curves; this also refers to the application of a compound curve. Thus the only solution becomes...
-
A modern approach to an unmanned vehicle navigation
PublikacjaA traditional approach to manned vehicles navigation uses a data combined form a variety of navigation sensors like satellite, inertial and time-of-flight. With support of operators perception, chart and sensor, data are analyzed and navigation decisions are made. An unmanned platforms navigation needs an operators support, who is supervising a platforms decision process, basing on navigation data obtained via variety of electronic...
-
Classification of Sea Going Vessels Properties Using SAR Satellite Images
PublikacjaThe aim of the project was to analyze the possibility of using machine learning and computer vision to identify (indicate the location) of all sea-going vessels located in the selected area of the open sea and to classify the main attributes of the vessel. The key elements of the project were to download data from the Sentinel-1 satellite [1], download data on the sea vessels [2], then automatically tag data and develop a detection...
-
The Methodology for Determining the Theoretical Based on the Characteristics of Effective Absorbency Versus Pressure Drop in the Motor
PublikacjaThis article describes a method for determining the theoretical and actual working volume of a hydraulic motor. It has been shown that the actual working volume of the motor is the sum of the theoretical working volume and the additional volume that depends on the pressure drop in the working chambers of the motor. It was also shown that the volumetric losses in the hydraulic motor are not only a function of the pressure drop in...
-
Design of compound curves adapted to the satellite measurements
PublikacjaThe paper deals with a novelty related to the design of a region for an alternative railway track direction adequate for mobile satellite measurements. The new approach may become particularly useful in the design of the existing track axis control when the determination of both the main track directions becomes impossible. The only solution in that case is to apply to the geometrical system two circular arcs of a different radius,...
-
Coastal zone monitoring using Sentinel-1 SAR polarymetry data
PublikacjaIn recent years the role of the surveillance and security of Polish boundaries has significantly increased. Polish coastal zone monitoring requires various approaches using various technological means in order to ensure the protection of Polish boundaries. In this paper, the authors discuss and present alternatives to underwater surveillance methods of coastal area analysis and monitoring using data retrieved from the newly developed...
-
The analytical design method of railway route’s main directions intersection area
PublikacjaThe paper presents a design method related to railway track sections situated in a bend. In the method advantage is taken of an analytical form of description by using appropriate mathematical formulae. This may becomeparticularly usefulwhen the investigations are based on the data obtained from mobile satellite measurements. In the paper attention is concentrated on an universal approach creating an opportunity to diversify the...
-
Three Editions of Inter-University Studies on Space and Satellite Technology. Candidate and/vs. Graduate, a Case Study
PublikacjaCurrently, there is a growing demand for most up-to-date academic courses that will fulfil the needs of modern society. Each candidate has to make choices and judgements carefully, in order to succeed on the market. This is particularly important when educating individuals with different backgrounds, especially on an inter-university course in the field of space sciences and technology. This paper describes a case study carried...
-
Maritime Communications Network Development Using Virtualised Network Slicing of 5G Network
PublikacjaThe paper presents the review on perspectives of maritime systems development at the context of 5G systems implementation and their main properties. Firstly, 5G systems requirements and principles are discussed, which can be important for maritime applications. Secondly, the problems of network softwarisation, virtualisation and slicing, and possible types of services for potential implementation in 5G marine applications are described....
-
PROBLEMS OF THE STARTING AND OPERATING OF HYDRAULIC COMPONENTS AND SYSTEMS IN LOW AMBIENT TEMPERATURE (PART V) METHODS ENSURING CORRECT START-UP OF HYDRAULIC COMPONENTS OF SHIP’S ONBOARD DEVICES IN LOW AMBIENT TEMPERATURES
PublikacjaA large number of hydraulic devices and systems are started in low ambient temperatures. A good example of such a device is the hoisting winch on the ship. Starting hydraulic drive units in thermal shock conditions (rapid supply of hot oil to the cold unit) may lead to incorrect operation of the actuating system, for instance, due to the loss of clearance between cooperating elements. The article presents methods to prevent the...
-
Automatic Detection and Monitoring of Cyanobacterial Blooms in the Context of the Marine Cadastre
PublikacjaIn the wake of the European and global spatial data infrastructures (SDI) it is important to build information systems which use and serve thematic data in compliance with the INSPIRE Directive. In the context of hydrographic data, the Directive requires EU member states to collect and share information on maritime areas divided into regions and sub-regions, as well as coastal zone management areas. These data are part of recently...
-
Asynchronous WAM with Irregular Pulse Repetition
PublikacjaRadiolocation systems for aviation based on Multi-Lateration (MLAT) typically use a set of synchronised ground sensors to receive radio signals broadcast by onboard transmitters. In most cases, the sensor synchronisation in Wide Area Multi-Lateration Systems (WAM) is provided by Global Navigation Satellite System (GNSS) receivers. However, in the case of synchronisation failure, there is still a possibility to estimate the coordinates...
-
Validation of Interpolation Algorithms for Multiscale UV-VIS Imaging Using UAV Spectrometer
PublikacjaIn this study, we present a comparison of popular methods for the interpolation of irregular spatial data in order to determine the applicability of each algorithm for hyperspectral reflectance estimation. The algorithms were benchmarked against a very high-resolution orthoimage from an RGB camera and medium-resolution satellite imagery from Sentinel-2A. We tested five interpolation algorithms: Triangulated Irregular Network (TIN),...
-
Evaluation of RTKLIB's Positioning Accuracy Using low-cost GNSS Receiver and ASG-EUPOS
PublikacjaThe paper focuses on a comparison of different positioning methods provided by free and open source software (FOSS) package called RTKLIB. The RTKLIB supports real‐time and post‐processed positioning. The most important modes of operation tested by the authors are Kinematic, Static, Fixed and Precise Point Positioning (PPP). The data for evaluation were obtained from low‐cost Global Navigation Satellite System (GNSS) receiver....
-
Nowe możliwości generowania zarysów satelitowych mechanizmów roboczych
PublikacjaPlanetary hydraulic gear motors have been well known since 70's . first motors were constructed for maritime industry by hydroster from gdansk. the evolution of this type of motors led to an increase of nominal pressure and durability. nowadays the industry needs reliable and efficient motor able to work with alternative hydraulic fluids like water, emulsion and vegetable oil. therefore a new type of motors are being developed...
-
RESOURCE ALLOCATION IN DAB+ BROADCASTING SYSTEM
PublikacjaWith over two billion receivers operating worldwide, radio transmission is by far the most accessible medium. It has been a part of our lives since the 1920’s and has become one of the most trusted and friendly mass media. Today, its popularity is still strong, despite the outcome of many electronic media. In order to transform the radio into a viable medium of the 21st century, it will have to migrate from analogue to digital...
-
Influence of YARN Schedulers on Power Consumption and Processing Time for Various Big Data Benchmarks
PublikacjaClimate change caused by human activities can influence the lives of everybody onthe planet. The environmental concerns must be taken into consideration by all fields of studyincludingICT. Green Computing aims to reduce negative effects of IT on the environment while,at the same time, maintaining all of the possible benefits it provides. Several Big Data platformslike Apache Spark orYARNhave become widely used in analytics and...
-
Determination of the theoretical and actual working volume of a hydraulic motor
PublikacjaA new methodology of determination of the theoretical and actual working volume of a hydraulic motor based on the characteristics of the delivered flow rate into hydraulic motor vs. the rotational speed at a constant pressure drop in the working chambers is described in this paper. A new method of describing the delivered flow rate into a motor per one shaft revolution as a nonlinear function of the pressure drop in the motor working...
-
Methodology for the Correction of the Spatial Orientation Angles of the Unmanned Aerial Vehicle Using Real Time GNSS, a Shoreline Image and an Electronic Navigational Chart
PublikacjaUndoubtedly, Low-Altitude Unmanned Aerial Vehicles (UAVs) are becoming more common in marine applications. Equipped with a Global Navigation Satellite System (GNSS) Real-Time Kinematic (RTK) receiver for highly accurate positioning, they perform camera and Light Detection and Ranging (LiDAR) measurements. Unfortunately, these measurements may still be subject to large errors-mainly due to the inaccuracy of measurement of the optical...
-
Framework for extracting rails and setting-out railway line axis based on UAV photogrammetric measurements
PublikacjaTechnical diagnostics enables assessing the current technical condition of a railway line and adjacent infrastructure, and forecasting its changes over a specific time horizon. One of its elements is the periodic monitoring of rail position and their geometry. This article presents a new framework for the setting-out of a railway track axis. The process presented in the manuscript is based on the specific filtration and extraction...
-
Influence of water and mineral oil on the leaks in satellite motor commutation unit clearances
PublikacjaThe article describes the flow rates of mineral oil and water flowing, as working media, through the commutation unit of a hydraulic satellite motor. It is demonstrated that geometrical dimensions of commutation unit clearances change as a function of the machine shaft rotation angle. Methods for measuring the rate of this flow and the pressure in the working chamber are presented. The results of pressure measurements in the working...
-
Efficient Usage of Dense GNSS Networks in Central Europe for the Visualization and Investigation of Ionospheric TEC Variations
PublikacjaThe technique of the orthogonal projection of ionosphere electronic content variations for mapping total electron content (TEC) allows us to visualize ionospheric irregularities. For the reconstruction of global ionospheric characteristics, numerous global navigation satellite system (GNSS) receivers located in different regions of the Earth are used as sensors. We used dense GNSS networks in central Europe to detect and investigate...
-
Geographic information system for remote integration of diverse under-water acoustic sensor data
PublikacjaMaritime and port areas throughout the world are exposed to many different hazards, like pollution, terrorism and natural disasters. Early detection, identification and preparation of appropriateesponse strategies is especially important in the case of semi-enclosed basins like the Baltic Sea, mainly due to the marine ecosystems' continuous absorption of pollutants including oil, heavy metals and chemicals. Many of those agents...
-
Digital Filtering of Railway Track Coordinates in Mobile Multi–Receiver GNSS Measurements
PublikacjaThe article discusses an important issue in connection with the technique of mobile Global Navigation Satellite System (GNSS) measurements of railway track coordinates, which is digital filtering performed to precisely determine railway track axes. For this purpose, a measuring technique is proposed which bases on the use of a measuring platform with a number of appropriately distributed GNSS receivers, where two of them determine...
-
The Influence of Water and Mineral Oil on Pressure Losses in Hydraulic Motor
PublikacjaIn this paper, pressure losses in hydraulic motor supplied with water and mineral oil (two liquids that have significantly different viscosity and lubricating properties) are described and compared. The experimental tests were conducted using a hydraulic satellite motor that is dedicated to working with different liquids, including water. The methodology of measuring the pressure drop in internal channels of this motor is also...
-
Sea surface temperature distribution during upwelling along the Polish Baltic coast
PublikacjaAmong over 150 maps of sea surface temperature in the Polish Baltic coastal region derived from satellite data during the warm period of the year (April-October) in 2000-2002, 41 cases were noted where its distribution showed characteristic features indicating the occurrence of coastal upwelling. The fundamental parameters of range, probability of occurrence and temperature modification caused by water from deeper sea layers...
-
Ionospheric scintillations computation using real-time GPS observations
PublikacjaThe following paper presents the results of quasi-real-time determination of the values of phase scintillations indices at the period of ionospheric disturbances that occurred as a consequence of the Sun flares observed on March 7 and 9, 2012. Double-frequency observations with 1-second measurement interval from the EPN (EUREF Permanent Network) network sites located at high latitudes were used for the analysis. To determine the phase...