Web Mapping Essay

CHAPTER 2

LITERATURE REVIEW

2.1 Mapping

Mapping is a process of map making where the earth features were represented in graphical form by using point, line and area symbols. Generally, when making maps, it involves cartographic disciplines. The International Cartographic Association defines cartography as the discipline dealing with the conception, production, dissemination and study of maps. The word cartography itself came from Greek words which are khrates and graphein, meaning map and write. A Map usually drawn on a flat surface and fitted with scales. Every map was drawn with projection since it involves the process of transferring information from a three-dimensional surface to a two-dimensional (flat) surface. There are three

As of not long ago cartography was confined to a few organizations, foundations and mapping agencies, require costly complex equipment and software and also cartography specialist. With the ascent of web mapping, a range of information and innovation was conceived. A variety of free software to create maps also has been developed and utilized together with proprietary tools like can be found in ArcGIS. Subsequently, the boundary for serving maps on the web has been brought down.

2.6.2 Types of Web Maps

Kraak (2001) made the first categorization of web map. Kraak differentiate static and dynamic web maps. Nowadays, there an expanded number of dynamic web maps, and static web map

Some of technologies utilized in web mapping are spatial databases, tiled web maps, vector tiles and WMS Server.

Spatial databases are object relational database which are improved with geographic data and properties. If a web mapping application need to utilize dynamic data; which changes oftenly or to utilize abundant geographic data, the usage of spatial database are needed. Spatial databases allow users perform geometry manipulations, spatial queries, and reprojections. It also provides a variety of import and export formats. The examples of spatial database provider are PostGIS, MySQL, Oracle Spatial, IBM DB2 and Microsoft SQL Server.

Tiled web maps technology provides the capability to display maps which are made up of raster image tiles. On the other hand, vector tiles map is resolution independent and is capable to show and hide features. Web Map Service is a web mapping service hosted on a remote server. Users can access to the map as long as their device are connected to the server. The Web Map Service just needs to send an image produce from the little part of the dataset that user viewed. This means, WMS is able to display map very fast. WMS servers produce maps by utilizing parameters for client options such as the arrangement of layer, symbolization, projection, and the data extent. GeoServer, UMN Mapserver and Mapnik are the example of open source WMS