Spatial data models are the methods through which geographical entities are stored and shown in computer systems. There are different ways in which the data is represented in a computer system. First of all there is map data. Map data is one of the easiest methods to understand in basic layman’s views. This is because is blatantly demonstrates the locations and names of certain areas. This shows lines and geographical points that are easy to understand.
Along with map data, there is also attribute data. It is the type of data that is descriptive and will be GIS linked to map features. This type of data is collected by individual states, provinces and cities and can be used in census tracts. Your own particular organization’s databases will be commonly combined with the databases that are purchased from other sources and means.
Along with map data, image data is another way to understand spatial data in a more easy way. Image data can be drawn from satellite images and aerial photographs. It can also be drawn from scanned maps, meaning that they have been converted from a printed format to a digital format.
Data models are agreed upon rules to ensure that country lines and province lines to not overlap. They are absolutely imperative in deciding what is in a GIS and for helping to support GIS software. Data models fall into two basic categories: vector and rastor.
Each model has its own specific benefits. By using vector, it is possible to represent data at its original resolution and form with out generalization. In addition, the graphic output from vector systems are generally more pleasing to the eye as they use traditional cartographic representation. As the majority of data is in vector form there us no need for data conversion. Vector allows for top efficiency in encoding of topology. However, the location of each vertex has to be stored explicitly with vector spatial data. In order for it to be most effective, all of the vector data must be converted into a topographical structure. Another disadvantage of the vector model is that continuous data such as elevation data is not effectively represented in vector form.
The rastor model has several advantages and disadvantages as well. Raster is beneficial to users because due to how the data is stored, the applicable analysis technique is generally easy to analyze and perform. Rastor maps are beneficial for mathematical modeling and quantitative analysis. Also, because rastor maps work on grid systems, they are very compatible with rastor based outsource services. But in spite of all of the benefits of a rastor model, there are also disadvantages. Because it is a cell system, the size of the cell is what determines the resolution at which all of the data is presented. In addition, if there is large amounts of data to process, that rastor system can make the task a little tedious because they usually only reflect one particular characteristic for an area.
Published At: Isnare.com
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