| Реферат: | eng: Usage of big geospatial datasets during climate change studies requires a set of Spatial Data Infrastructure (SDI, [1]) elements be developed and published, including, in particular, geoprocessing web services and services of cartographical visualization. According to OGC specifications the basic functions performed by spatial data services are the following: geospatial data visualization (WMS), data provision in vector (WFS) and raster (WCS) formats, as well as geospatial analytical processing (WPS). The paper presents the architecture of the geospatial OGC web services system as an integral part of the virtual research environment (VRE) general architecture for statistical processing and visualization of meteorological and climatic data. The architecture represents a set of interconnected standalone SDI nodes along with corresponding data storage systems, each node running the specialized software such as SDI geoportal, cartographical web services (WMS/WFS) based on Geoserver (http://geoserver.org/), metadata catalog based on Geonetwork Opensource (using CSW standard), MySQL database of technical metadata describing geospatial datasets available for the node, and geospatial data processing services (WPS) based on modular computing core realizing statistical processing functionality and thus providing access, complex processing and analysis of big datasets, along with results visualization and export into the files of standard formats (XML, binary, etc). Data storage systems contain geophysical spatial netCDF datasets, including numerical modeling and reanalysis data as well as meteorological observations, grouped by thematic characteristics. Within the general architecture framework the nodes' MySQL metadata databases and their interconnections have fundamental value. The metadata database of the central node contains descriptions of all the SDI nodes available in the system as a whole, while each of them in turn is connected to a set of computing servers (Computing system #1, ...), data storages and, finally, locally available datasets. The table of SDI node descriptions consists of such fields like name, title, URL, and node's geoportal MySQL database connection parameters. All other secondary nodes contain the central metadatabase replica that allows geoportal applications to check the information about datasets available for processing for each node, as well as computing modules for their processing. The central metadata database can be administered by the senior system administrator, while nodes' administrators have "read-only" access rights for it and its replicas. Due to this approach end users are provided with the information about all the geographically distributed datasets available in the system, regardless of the availability of direct network connections to the remote databases at any time. Cartographical web services elaborated within the framework of the system prototype development implement user access rights separation and provide functional capabilities to work with raster (GeoTIFF) and vector (Shapefile, PostGIS) geospatial data based on OGC WMS, WFS, WPS services. WPS cartographical service in general provide standardized external HTTP interface used for remote configuration and running geospatial data statistical processing as well as result presentation in the formats corresponding to the end user formalized instructions. The distributed architecture presented allows smooth adding of new nodes, computing and data storage systems as well as provides solid computational infrastructure for regional climate change studies based on modern Web ad GIS technologies.
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| Цитирование: | 1. Steiniger S., Hunter A.J.S. Free and open source GIS software for building a spatial data infrastructure. / In: Bocher E., Neteler M., (eds.), Geospatial Free and Open SourceSoftware in the 21st Century, LNGC, Heidelberg, Springer, 2012a, p. 247-261.
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