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GIS software at a glance

It was in the early 1960s that the seeds for the foundations of Geographic Information Systems (GIS) were laid down. However, it took almost three decades for the seed to mature into a healthy concept with the ever-growing branches entering into almost all visible fields and touching every aspect of our life. This remarkable progress would not have been possible had it not been for the proper inputs and supports the seedling received from the industry and the scientific community. The combined efforts resulted in building of a strong foundation of GIS, which today boasts itself as one of the fastest growing field in geo-science. Behind this remarkable growth is the relentless efforts of the industry to bring out with good quality software which helps in providing the best quality outputs. The following sections provide an outline of some of the major software which have revolutionised the mapping community.

ArcView GIS is a desktop mapping and GIS software used as a tool for the management, display, query and analysis of spatial information. It links the traditional analysis tools like spreadsheets, databases and business graphics with maps for a completely integrated analysis system. ArcView GIS software’s extensible architecture adds on to the capabilities. Extensions like ArcView Spatial Analyst allows to create, query, map and analyse cell-based raster data and to perform integrated vector-raster analysis. The ArcView 3D Analyst extension enables users to create, analyse and display surface data. ArcView Image Analysis enables ArcView GIS users to go beyond using images as a backdrop for vector maps. Digital imagery can also be used for data visualisation, data extraction/creation and analysis. ArcView Image Analysis allows to leverage a broad range of readily available image data types—including popular satellite imagery, aerial photography, orthoimagery, and other remotely sensed data—supplementing a wide variety of GIS applications.

ArcInfo differs from ArcView in that ArcInfo is designed to develop GIS data while Arcview is designed to interact with GIS data which has already been created. It is used to automate, manipulate, analyse, and display geographic data and incorporates hundreds of sophisticated, yet easy-to-use tools for map automation, data conversion, database management, map overlay and spatial analysis, interactive display and query, graphic editing, and address geocoding. It enables to integrate vector (x,y locations) map data, raster images such as photographs, scanned documents or satellite images, CAD drawings, sound and video data, as well as a wealth of tabular DBMS data into a single, integrated environment. ArcMap application which enables the user to do CAD-like editing, assist with advanced mapping capabilities and support better visualisation for superior data interpretation and analysis. ArcCatalog is the ArcInfo application for locating, browsing and managing spatial data. ArcToolbox is the ArcInfo application that is used in performing operations such as data conversion, overlay processing, buffer creation and map transformation.

AutoCAD Map software is based upon AutoCAD Release 14. It enhances the operation of AutoCAD in the GIS marketplace by providing standard GIS functionality with topology creation, analysis and thematic mapping, fully integrating raster and vector file formats, and providing links to attribute information through object data or external databases. AutoCAD Map is fully compatible with existing Auto-CAD-based drawings and maps, in part, because its data creation foundation is AutoCAD Release 14. The program can utilise spatially referenced data in a number of standard map file formats. The graphical user interface streamlines the attachment of attribute data to point and line objects and allows real-time pan and zoom. Analysis functions include map algebra commands that allow for the overlay of node, network, or polygon topologies. Overlay functions include intersect, union, identity, erase, clip, copy and paste. Topology generation is present in node, link, and polygon formats. Cleaning up digitised or imported data is easily implemented. A number of map clean-up tools such as extend undershoots, edge-matching, and breaking objects at map boundaries are present. Imported maps can be rubber-sheeted through rotate, scale, and stretch commands to conform to an existing coverage or base map. Import and export filters include MicroStation Design files (*.dgn), Map-Info Interchange files (*.mif), ArcView Shape files (*.shp), and ArcInfo Coverages.

MapInfo is a comprehensive desktop mapping software with a powerful graphical display program. It can be used to perform complex geographic analysis such as redistricting, linking to remote data, dragging and dropping map objects into applications, creating thematic maps emphasising patterns in data. Other features include live ODBC access t remote databases, cartographic legends, Seagate Crystal Reports and grid surface thematic mapping. It has a good SQL query capability for retrieving and displaying spatial and non spatial information. The MapBasic programming language released along with MapInfo allows third party developers to produce platform-independent utilities to automate many routines within MapInfo or to extend the capabilities of the MapInfo program beyond its present envisioned uses.

A very successful story in GIS is Intergraph’s product GeoMedia. The GeoMedia product suite includes GeoMedia, GeoMedia Professional, GeoMedia Web Map and GeoMedia Web Enterprise. GeoMedia products range can be used to integrate disparate data across platforms, convert map projections into one common projection and perform analysis of these different datasets in relation to one another, no matter where the data resides. GeoMedia data server technology allows to view multiple data sets in various formats but also to analyse this information by running queries, buffer zones and thematics across multiple GIS formats. GeoMedia data server technology allows to view multiple data sets in various formats but also to analyse this information by running queries, buffer zones and thematics across multiple GIS formats. With GeoMedia’s dynamic segmentation capabilities linear and point data can be querried and segmented from multiple MGE databases. GeoMedia offers geocoding, which translates tabular data into spatial data. GeoMedia supports Oracle, including Oracle8i Spatial, as geospatial warehouse.

One of the most popular GIS software among students is IDRISI developed and distributed on a non-profit basis by the Clark Labs, University in Worcester. Idrisi is a good software for raster analytical functionality covering the full spectrum of GIS and Remote Sensing needs from database query to spatial modelling, to image enhancement and classification. Idrisi uses the latest object-oriented development tools. Special facilities are included for environmental monitoring and natural resource management, including change and time series analysis, multi-criteria and multi-objective decision support, uncertainty analysis (including Bayesian and Fuzzy Set analysis) and simulation modelling (including force modelling and anisotropic friction analysis). TIN interpolation, Kriging and conditional simulation are also offered. In addition, Idrisi is COM-complaint, allowing programmers and modellers to incorporate Idrisi routines into their own applications.

ILWIS uses an object- oriented approach in which maps, such as point, segment, polygon and raster maps are data objects. Tables form another type of data objects. Each is represented by an icon in the data catalogue. ILWIS makes use of domains, defining the possible contents of a map, table or column in a table. Domains are linked to a representation of colours, patterns, points and line thicknesses. Other important features of the software are: Display of multiple maps and annotation layers in one map window, extensive vector and raster data management tools, 3D views with interactive editing of view parameters, interactive and simultaneous data retrieval of multiple maps and attribute tables together with editing of attribute information, extensive image processing facilities and several types of geo-statistical analysis.

Now adays one more software is gaining popularity among the mapping community i.e. TNTmips which is MicroImages flagship product for geospatial analysis. TNTmips is used for GIS, advanced image processing, CAD, desktop cartography, electronic atlas preparation and other spatial database management and visualisation applications. TNTmips offers several tools like the same raster object display tools for zooming in, zooming out, panning, colour manipulation, histogram display, and cell value inspection. Raster object cell values can be used as elevation values to create colour 3D draped surface images in parallel or perspective views. Relational databases that contain attributes for vector and CAD elements may be queried dynamically to determine complex display, plotting and drawing styles.n

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