EXPERT GEOPORTAL SYSTEM

Abstract

Geoportal is the web gateway of the Spatial Data. It is the building block for providing the Spatial Information to the web user either it is a thick or a thin client. Geoportal is the web interface for finding and accessing geographic information. Various, diversified sources of information in different Geoportal arranged in the form of suited for their requirements. The information is updated and maintained by different agencies. They allow use of data free of charge for non profitable use. Most of these portals develop on a non GIS platform which are poor in decision making and many times much more facilities and features are required by GIS users. The GIS community has a different approach to store, manage, present data for real time query based information extracts in spatial domain. One option is to create own data as created by Non GIS portals, and other is to extract real time data from Non GIS portal and use in own GIS Standard portal without illegally accessing the service provider database for non profitable use, which require advance concept as writing program to access own database is a common technology, but accessing data from a third party web portal in real time without entering into their central server requires technology to understand their framework, data storage etc. which comes under Reverse Engineering. Present study designed and developed a system known as EGPS (Expert Geoportal System) after getting an idea from new emerging technology like web mashups. Web mashup is a cost effective solution as it works on a principle of providing new services by using the data or services already present on the web, instead of creating an entirely new system from scratch. For providing this type of solution needs a good understanding of cross domain issues, security, copyrights etc. Expert Geoportal System (EGPS) is designed and developed by using Html, Asp. Net (server side scripting language), JavaScript (client side scripting language), Google API’s (providing spatial information), GDAL (open source library) and VBA (Excel Macros) in Visual Studio 2008. This browser based application provides different GIS functionalities like location based services, weather forecasting, growth and pattern analysis, DEM and Geotiff images by using diverse source of data already present on the web. For providing location based services, it used front end data of Makaan.com and Yahoolocal.in web applications. For providing difference images, growth analysis and pattern analysis graph, it uses temporal NDVI images provided by the Global Agriculture Monitoring (GLAM) Project website and to provide DEM and Georeferenced image, it used Google Earth API’s. Location based services provided by EGPS enhanced the capabilities of Makaan.com and yahoolocal.in website by providing answers of more complex queries like “how many apartment are present inside 5 km area”, “how many hospital are present inside 25 km area” etc. by rearranging their front end data with the help of VBA programming and creating buffers of different diameter in Google Map APIs which help in better decision making. To provide Local Weather Forecasting information for an entire buffer EGPS repeatedly call the freely available weather services of wunderground.com web application by passing the location based attributes (captured from the makaan.com or yahoolocal. in a web application). Digital Elevation Models (DEM) is data files that contain the elevation of the terrain over a specified area, usually at a fixed grid interval over the surface of the earth. EGPS uses Google Earth APIs for providing DEM file by enhancing its capabilities, as Google Earth does not provide a direct API for DEM generation, so EGPS deployed a new system where users can specify the grid interval by selecting horizontal and vertical pixel value according to their requirement. The output file is automatically saved in text (.txt) format which contains elevation values of a grid point with its latitude and longitude. NDVI data is suitable to examine the longer term event like the growth of vegetation through a season (NDVI, 2002; Umesh et.al.,2013b). For providing real time vegetation growth and pattern analysis EGPS uses the temporal NDVI images provided by the GLAM website. A web based interface is developed for capturing the NDVI images, these images are further classified and graphs are plotted at run time for decision making. This system is more suitable for automatic forecast of the vegetation pattern change analysis; the data needed for this type of analysis is not only very costly but also not easily available. Georeferencing is the primary essential step to define spatial data in a coordinate system to relate it to its exact location over earth defined through projection systems. As this procedure is mandatory for data modeling. So, Expert Geoportal System (EGPS) deployed a new referencing system that is used to establish the relation between raster data collected by capturing Google earth images at run time for different GIS application. There is a large significance of this research work as providing these functionalities by creating a new web portal from scratch, not only needed a costly investment but many time increases the duplication of data on the web. It reduces the burden of managing database, need of understanding of spatial domain knowledge, purchasing of costly software etc. This study also helps in data modelling because it reduces the lengthy procedure of generation of DEM file and Geotiff images as through this software these works can be done in a single click. This study also specifies the various issues regarding the Mashup based application like cross domain, security, copyrights etc. It also recommends some future scope as there is a need to increase computation speed and processing time of a developed system etc.