Glimpse of GIS (2)

Since the 1970's, the GIS has developed rapidly. This development was mainly the development of information technology and telecommunications, among others:

Revolution of information technology: computer technology, remote sensing and Global Positioning Systems. Technology communication. Drastically decreases the price of computers and the increasing speed of computer work. Increasing software functionality and ease of use. Evidence of the adage "a picture is worth a thousand words. Roman face of the earth related to our lives.

GIS has its own advantages compared to other information systems, which have the ability to customize data from different sources to analyze the trend of future development and evaluation of the spatial effect. GIS is an effective tools for implementing and monitoring the local infrastructure. The use of GIS is increasingly popular for project planning, make better decisions, and improve the analysis of visual integrity of the organization.

  

Components of GIS

GIS has five components, namely hardware, software, data, people and methods:Hardware: Hardware is the contents of a computer system that runs the GIS software. Scanner and digitizer table is the hardware to convert images into digital systems and object vectorisasi map. Printer and plotter output is a GIS tool.

 

Software: Software to run a GIS consists of the operating system, compiler and application programs. OS (Operating System): controls the entire operation of the program, also connect the hardware to the application program. For PC: MS-DOS (IBM PCs) and WINDOWS operating system is widely used. For Workstation: UNIX and VMS is the dominant OS. Compiler: translates programs written in machine code that a computer on the CPU capable of running the program to be executed. Compiler language used is C, Pascal, FORTRAN, BASIC, etc.. Program Application: Software GIS has the functions and tools to store, analyze and display geographic information. Some GIS software is used between alin, Mapinfo, Arc / Info, ArcView, ArcGIS, Grass, and MapWindow. GIS software exist that are "open sources" which means it can be used by anyone without charge and there is a need to pay. Open sources software developed to date is GRASS (now version 6.2) based Linux and Microsoft based MapWindow.

Data: Data of geographic and tabular data accompanying workspace can be obtained at or through the purchase of commercial data providers. Official agency that provides digital data. Institutions in Indonesia which generates digital data, for example, which produces digital maps Bakosurtanal earth manner.

 

Human: The user starts from the GIS technicians who design and maintain systems to users of the system. Highly skilled operator to determine the effectiveness of input data, repair data, data manipulation accordance with the purpose of the project and display the work of the GIS. In humans who operate GIS operations can be divided up, technicians, operators and programmers.

Procedure: There are several techniques used to produce maps and advanced usage for a project. Map-making can be done automatically create a data vector from raster done manually or using image scanning . Source of digital maps can be obtained from surveys or satellite imagery.Some of the key areas of GIS application are:

• Differences in current planning Urban planning, housing, transportation planning, architectural conservation, urban design and landscape.

• Network road traffic routes and schedules, locations and places as well as disaster planning options.

• Natural resource management and environmental impact analysis of natural resources and attractions, area flooding, wetland, acuifers, forestry and wildlife.

• The presence of hazardous and toxic materials, groundwater models, the study kehidupn wild habitat and migration route planning.

• Zoning of land division, inspection pewilayahan plan, land ownership, environmental impact analysis, quality management and improvement of nature.

• Location of facility management pipes and cables underground, plan, track energy usage.

GIS success depends on:

  - Data and mapsSoftware in the computer do the calculations and analysis software and GIS requires good data and human resources. GIS software package is a combination of map geometry that is managed by the graphics techniques and Computer Aided Design (CAD) as well as attribute information to spreadsheet and database techniques.

  Main functions of GIS

  1. Retrieving DataGIS data used is always obtained from the various types and stored in a different way. GIS provides the tools and methods to integrate disparate data into a format that can be compared and analyzed. The main data source is obtained from the manual and penyiaman digitization (scanning) aerial photographs, sheet maps and digital data sets that already exist. Remote sensing and GIS GPS is a source of data that continues to growing . Data retrieval through manual digitization is still a common method for inserting maps into GIS. Digitized maps that will be placed on the digitizing table, and digitization is done by using the cursor or mouse to follow an existing feature on the map. Feature may be the boundary line between the map, in part shaped lines (rivers, roads, etc.) or a point (sample point, railway station etc.). Electronic digitizing table to record the position of the cursor. In addition to digitization, in order to obtain the data is to use the scanner. scanning is faster than entering data manually digitized. Results scannner a digital raster image containing cells in large numbers and are arranged as columns and rows. Good job maps scanning obtained from a clean, simple, connected to only one feature and does not contain information such as text or image symbolism. Example, on a contour map shows contour lines only, without the high mark, drainage or infrastructure networks. scanning and data conversion can be done with software such as Raster to Vector (R2V).

2. Data ConversionWhen manipulated and analyzed the data, all data must be the same format. Usually conversion from vector to raster done, because most of the analyzes carried out in raster form. The data vector to raster transformation is done by using a grid overlapping sell a specified size. Data conversion raster to vector the data undertaken to reduce data storage for the data stored in raster data requires a larger space than the data vector. File digital data with spatial data and its attributes can be displayed in various ways. For example, based on administrative, or other soil types. In some cases the conversion needs to be done before the data is entered as a database. Generally attribute data using dBase and Oracle, as well as a spreadsheet program such as Lotus, Quatro or Exel. Remote sensing imagery is the digital data recorded by satellite and stored in its own image database. Usually converted to a form of database (raster) before revealed.

3. Storing and Updating DataCollected and integrated data can be stored and updated by the GIS is to provide storage facilities and repair data. Effective data management aspects related to data security, data integration, storage and repair and maintenance of data. Integration and data conversion is one part of the GIS data input stage.

4. Data interpretation and analysisThe next requirement is the interpretation and analysis of quantitative and qualitative information collected. For example, satellite imagery can help agricultural experts to determine the agricultural production per hectare for certain areas. For that the experts have rainfall data for the previous 6 months were collected from the weather observation station. Rainfall data can be interpolated to obtain thematic maps showing isohyets of rainfall or contour lines. The experts must also have a map showing the area of ​​land fertility and suitability for agriculture.