Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
7
result(s) for
"Grids (Cartography) Data processing."
Sort by:
A GPU-Based Integration Method from Raster Data to a Hexagonal Discrete Global Grid
This paper proposes an algorithm for the conversion of raster data to hexagonal DGGSs in the GPU by redevising the encoding and decoding mechanisms. The researchers first designed a data structure based on rhombic tiles to convert the hexagonal DGGS to a texture format acceptable for GPUs, thus avoiding the irregularity of the hexagonal DGGS. Then, the encoding and decoding methods of the tile data based on space-filling curves were designed, respectively, so as to reduce the amount of data transmission from the CPU to the GPU. Finally, the researchers improved the algorithmic efficiency through thread design. To validate the above design, raster integration experiments were conducted based on the global Aster 30 m digital elevation dataDEM, and the experimental results showed that the raster integration accuracy of this algorithms was around 1 m, while its efficiency could be improved to more than 600 times that of the algorithm for integrating the raster data to the hexagonal DGGS data, executed in the CPU. Therefore, the researchers believe that this study will provide a feasible method for the efficient and stable integration of massive raster data based on a hexagonal grid, which may well support the organization of massive raster data in the field of GIS.
Journal Article
Topographic surface modelling using raster grid datasets by GMT: example of the Kuril–Kamchatka Trench, Pacific Ocean
The study area is focused on the Kuril–Kamchatka Trench, North Pacific Ocean. This region is geologically complex, notable for the lithosphere activity, tectonic plates subduction and active volcanism. The submarine geomorphology is complicated through terraces, slopes, seamounts and erosional processes. Understanding geomorphic features of such a region requires precise modelling and effective visualization of the high-resolution data sets. Therefore, current research presents a Generic Mapping Tools (GMT) based algorithm proposing a solution for effective data processing and precise mapping: iterative module-based scripting for the automated digitizing and modelling. Methodology consists of the following steps: topographic mapping of the raster grids, marine gravity and geoid; semi-automatic digitizing of the orthogonal cross-section profiles; modelling geomorphic trends of the gradient slopes; computing raster surfaces from the xyz data sets by modules nearneighbor and XYZ2grd. Several types of the cartographic projections were used: oblique Mercator, Mercator cylindrical, conic equal-area Albers, conic equidistant. The cross-section geomorphic profiles in a perpendicular direction across the two selected segments of the trench were automatically digitized. Developed algorithm of the semi-automated digitizing of the profiles enabled to visualize gradients of the slope steepness of the trench. The data were then modelled to show gradient variations in its two segments. The results of the comparative geomorphic analysis of northern and southern transects revealed variations in different parts of the trench. Presented research provided more quantitative insights into the structure and settings of the submarine landforms of the hadal trench that still remains a question for the marine geology. The research demonstrated the effectiveness of the GMT: a variety of modules, approaches and tools that can be used to produce high-quality mapping and graphics. The GMT listings are provided for repeatability.
Journal Article
Large-scale geo-tagged video indexing and queries
With the wide spread of smartphones, a large number of user-generated videos are produced everyday. The embedded sensors, e.g., GPS and the digital compass, make it possible that videos are accessed based on their geo-properties. In our previous work, we have created a framework for integrated, sensor-rich video acquisition (with one instantiation implemented in the form of smartphone applications) which associates a continuous stream of location and viewing direction information with the collected videos, hence allowing them to be expressed and manipulated as spatio-temporal objects. These sensor meta-data are considerably smaller in size compared to the visual content and are helpful in effectively and efficiently searching for geo-tagged videos in large-scale repositories. In this study, we propose a novel three-level grid-based index structure and introduce a number of related query types, including typical spatial queries and ones based on bounded radius and viewing direction restriction. These two criteria are important in many video applications and we demonstrate the importance with a real-world dataset. Moreover, experimental results on a large-scale synthetic dataset show that our approach can provide a significant speed improvements of at least 30 %, considering a mix of queries, compared to a multi-dimensional R-tree implementation.
Journal Article
INTRODUCING A DATA-DRIVEN APPROACH TOWARDS THE IDENTIFICATION OF GRID CELL SIZE THRESHOLD (CST) FOR SPATIAL DATA VISUALIZATION: AN APPLICATION ON MARINE SPATIAL PLANNING (MSP)
Spatial data visualization techniques may have a great influence in several disciplines related to spatial management and hence decision-making process. Among them, marine spatial planning (MSP) constitutes an integrated procedure aiming at the optimal allocation of human activities in marine space. In MSP, mapping process referred either in human activities, marine ecosystems or indicative indices is based on the implementation of a grid approach. The present paper discusses some critical issues related to visualization procedure while a new data-driven approach is introduced towards the identification of grid cell size threshold. The proposed method gives a critical suggestion that may be easily extended in each field that considers this type of visualization for spatial data handling.
Journal Article
Reference model for a data grid approach to address data in a dynamic SDI
A grid is concerned with the integration, virtualization, and management of services and resources in a distributed, heterogeneous environment that supports virtual organizations across traditional administrative and organizational domains. Spatial data infrastructures (SDI) aim to make spatial data from multiple sources available and usable to as wide an audience as possible. The first SDIs of the 1990s followed a top–down approach with the focus on data production and centralization. In recent years, SDIs have seen a huge increase in the number of participants, necessitating a more dynamic bottom-up approach. While much research has been done on web services and SDIs, research on the use of data grids for SDIs is limited. In this paper an emergency response scenario is presented to illustrate how the data grid approach can be used as a decentralized platform for address data in a dynamic SDI. Next, Compartimos (Spanish for ‘we share’) is presented, a reference model for an address data grid in an SDI based on the Open Grid Services Architecture (OGSA). Compartimos identifies the essential components and their capabilities required for a decentralized address data grid in a dynamic SDI. It deviates from the current centralized approach, allows data resources to come and go and node hosts to grow and shrink as necessary. An address data grid in an SDI is both a novel application for data grids as well as a novel technology in SDI environments and thus advances the mutual understanding between data grids and SDIs. In conclusion, additional research required for address data grids in SDIs is discussed.
Journal Article
The Conception of the Net Weather Station for Measuring the Microclimate of the Forest
The project of meteorological station is designed to monitor the state of the weather on the selected (forest areas) as well as the colleting the data to analyze the dynamic of the changes weather parameters. The main idea presented in this paper, base on assumption that single weather station can be used as a part of net. The simultaneous and continuous measurement of many parameters such as temperature, pressure, humidity and sunlight located at grid points could work out finally the weather map combined with the digital terrain model. The modern electronic make possible flexible connecting individual stations in subsystems and exchange of huge amount of information leading to build base knowledge. In the first part of the article it is presented the conception of the information system. In the next part there are outlined the results of works with the prototype of the measure mode. Dedicated to applications in forestry prototype of device, can be used to measure temperature, pressure, humidity and sunlight. The additional features of the device are the possibility of writing data on micro SD card, supplemented with current time, day, and year. The design and research is a pilot, before the creation of a regular grid of sample plots with the use of many such devices. The objective is to gather accurate meteorological data from the interior of the forest-based geostatistical analysis, necessary for breeding purposes. Because of their design frames weather, it can be installed on most trees. Presented prototype of basic station used in the concept of measuring net, generates data from the sensors, which are strongly correlated with the compared professional station.
Conference Proceeding