Geographic Information System _GIS_ by dyanrestuokt


									Understanding GIS
Geographic Information System (GIS) or Geographic Information System (GIS) is an
information system designed to work with spatially referenced data or berkoordinat geography or
in other words, a GIS is a database system with specific capabilities for handling spatial
referenced data ( spatial) working in conjunction with a set of operations (Barus and
Wiradisastra, 2000). Meanwhile, according to Anon (2001) Geography Information System is a
system that can integrate information between graphical data (spatial) with text data (attributes)
that are connected in geogrfis objects on earth (GIS). In addition, GIS can also combine data,
organize data and perform data analysis which ultimately will result in output that can be used as
a reference in decision-making on issues related to geography.
Geographic Information System is divided into two groups: a manual system (analog), and
automated systems (digital-based computers). The most fundamental difference lies in the way
of management. Information system manuals usually incorporate some data like maps,
transparencies to overlap stacking (overlay), aerial photographs, statistical reports and field
survey reports. All data is compiled and analyzed manually with a tool without a computer.
While automated Geographic Information System has been using the computer as a data
processing system through a process of digitization. Source of digital data can be either satellite
imagery or digital aerial photographs and digitized aerial photographs. Other data can be
digitized base map (Nurshanti, 1995).
Understanding GIS / SIG today is more often applied to the spatial or geographic information
technologies oriented to the use of computer technology. In conjunction with computer
technology, Arronoff (1989) in Anon (2003) defines GIS as a computer-based system that has
the ability to handle data that is referenced geographic data entry, data management (storage and
recall), manipulating and analyzing data, and output as the final result (output). While Burrough,
1986 defines Geographic Information System (GIS) as a computer-based systems are used to
input, store, manage, analyze and re-enable the data that have a spatial reference for various
purposes related to mapping and planning. The main components of Geographic Information
System can be divided into four main components: hardware (digitizer, scanner, Procesing
Central Unit (CPU), hard-disk, etc.), software (ArcView, Idrisi, ARC / INFO, ILWIS, MapInfo,
etc.), organization (management) and user (the user). The correct combination of the four main
components of this will determine the success of a Geographic Information System development
GIS applications can be used for various purposes for which data is processed to have
geographic references, meaning the data is composed of a phenomenon or object that can be
presented in physical form and has a spatial location (Indrawati, 2002).
The main objective of the utilization of Geographic Information System is to facilitate getting
information that has been processed and stored as an attribute of a location or object. The main
characteristic of data that can be used in Geographic Information Systems is the data that has
been tied to location and is the basic data that has not been specified (Dulbahri, 1993).
The data are processed in a GIS is essentially composed of spatial data and attribute data in
digital form, thus the analysis can be used is the analysis of spatial and attribute analysis. Spatial
data is data relating to the spatial location of the general shape of the map. While the data
attribute is a data table that serves to explain the existence of various objects as spatial data.
The presentation of spatial data has three basic ways in the form of dots, lines form and shape of
the area (polygon). Point is a single appearance of a pair of coordinates x, y which shows the
location of an object of height, location of the city, sampling locations and others. The line is a
set of points which form an elongated appearance such as rivers, roads, etc. kontus. While the
appearance of the area is bounded by a line which forms a homogeneous space, for example:
regional boundaries, limits the use of land, islands and so forth.
Spatial data structure that is divided into two models of raster data and vector data models.
Raster data is the data stored in the form of a rectangular box (grid) / cell, forming a regular
space. Vector data is the data recorded in a form that displays the coordinates of points, placing
and storing spatial data using points, lines or areas (polygons) (Barus and Wiradisastra, 2000).
Lukman (1993) states that the geographic information system provides spatial information and
its attributes which consists of several main components, namely:
1. Input data is the data entry process on a computer from maps (topographic maps and thematic
maps), statistical data, data analysis results of remote sensing data from remote sensing digital
image processing, and others. Spatial data and attribute either in the form of analog or digital
data is converted into the format requested by the software, forming a database (database).
According to Anon (2003) database is organizing the data that is not redundant in the computer
so it can do the development, renewal, calling, and can be used jointly by the user.
2. Data storage and recall (data storage and retrieval) is a data storage on the computer and call
back quickly (look at the screen and can be displayed / printed on paper).
3. Data manipulation and analysis activities that can be done is a variety of command between
the two themes such as overlaying a map, create a buffer zone some distance from an area or
point, and so on. Anon (2003) says that the manipulation and analysis of data is a major feature
of the SIG. GIS capabilities in a joint analysis of spatial data and attribute data will yield
information useful for various applications
4. Reporting data is able to present the basic data, the data processing results from the model data
into the form of maps or tabular data. According to Barus and wiradisastra (2000) form of the
product of a GIS can be varied both in terms of quality, accuracy and ease of the wearer. These
results can be made in the form of maps, tables figures: the text on paper or other media (hard
copy), or in the print software (such as electronic files).

According to Anon (2003) there are several reasons why it is necessary to use GIS, including:
1. GIS uses spatial and attribute data in an integrated
2. GIS can digunakansebagai exciting interactive tool in the effort to increase understanding of
the concept of location, space, population, geography and the elements that exist on the surface
of the earth.
3. GIS can be split between the form of presentations and databases
4. GIS has the ability to decipher the elements that exist on the surface of the earth into several
layers or spatial data coverage
5. SIG has a very good Traffic in visualizing spatial data following attributes
6. All GIS operations can be performed interactively
7. GIS easily menghsilkan thematic maps
8. all GIS operations can be in the Customize by using the commands in the script Bahaa.
9. Peragkat GIS software provides the facility to communicate with other software
10. GIS greatly helped the work that is closely related to the field of spatial and geoinformatika.
Barus and Wiradisastra (2000) also revealed that the SIG is a reliable tool for handling spatial
data, where the GIS data is maintained in digital form so that this data is more dense than in the
form of printed maps, charts or in other conventional forms that will eventually speed up the
work and alleviate the cost required.
Primary means for spatial data handling is a GIS. GIS is designed to receive large amounts of
spatial data from various sources and mengintergrasikannya become an informed, one type of
data is remote sensing data. Remote sensing has the ability to generate spatial data structure with
a geometry close to the real situation quickly and in large quantities. Barus and Wiradisastra
(2000) says that the SIG will give added value to the remote sensing capability to produce large
spatial data in which the utilization of remote sensing data depends on how the handling and
processing of data which will convert it into useful information.

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