A GIS (geographic information system) is the computerized system that facilitates four sets of capabilities to handle georeferenced data including:
1. Data Capture and Preparation
2. Data Management (storage and maintenance)
3. Data Manipulation and Analysis
4. Data Presentation
Before we can use a GIS, we must understand what data we can obtain, how to obtain it, and how to properly prepare it. This is the early stage in which data about the study phenomenon is collected and prepared to be entered into the system.
When looking at geo-referenced data, it is important to be knowledgeable about the geographic phenomena we are describing, how they are represented as geographic representations, and the data types and values that can be used.
For data capture, there are many data entry sources that can be primary sources or secondary sources. Some examples of data entry sources are: aerial surveys and remote sensing,a terrestrial survey,field surveys,digitizing,scanning, and a Mobile GIS.
When considering data preparation for GIS, it is also important to consider the regulated standards and data quality, regardless if your sources are primary or secondary.
In the GIS working environment, we are able to analyze and manipulate large amounts of data. Therefore, it is vitally important that data is manageable, navigable and of satisfactory quality. The easiest way to obtain all these qualities is through database. However, these databases still required to be updated and checked if they are used frequently, and by multiple users. This is done through Data Management Systems (DBMS).
One of the key features of GIS is the variety of analysis functions and processes. However, when manipulating data, it is important to consider looking at Spatial Variation through techniques like empirical variograms or concepts such as topology. The streamline of data manipulation and analysis can become long, so it is important to track all of the steps when working with a GIS, and consider error propagation. If you are working with poor data, no amount of analysis will produce good results.
One of the main goals of the GIS is to present spatial information in an efficient way. The characteristic of maps and their functions in relation to the spatial data handling process was explained in the previous section. In this context the cartographic visualization process is considered to be the translation or conversion of spatial data from a database into graphics. During the visualization process, cartographic methods and techniques are applied. These can be considered to from a kind of grammar that allows for the optimal design, production, and use of maps depending on the application. It is good to refer to data types and values when beginning your visualization process to ensure your success.
Explain the basic architecture of a GIS, its main components and how these components are related (level 2). Create a simple spatial database given a spatial problem (level 1, 2 and 3).