Geographic Information System (GIS)

Geographic Information System is used in many fields such as scientific research, resource management, asset management, archaeology, environmental impact assessment, civil planning, cartography, criminology, geographic history, marketing, transportation and shipping etc. In addition to that, it helps save lives and reduce material losses by providing a selection of the best and shortest routes for ambulances and fire engines to reach cases of emergency. It also helps private companies save time, effort and money by allowing them to communicate more effectively with their distributors and their sales staff.

How does GIS work?

GIS takes the terms and the numbers from the databases and spread sheets, and displays them clearly on the map. After displaying the data, GIS can identify the place (the address) we are looking for, such as parking lots, bus stops, metro stations, shopping centres or ATMs. In this sense, GIS allows us to view, understand, question, interpret and visualise the data in ways that cannot be obtained on electronic charts.

Geospatial technology

Geospatial technology involves the combination of spatial software and analytical methods with terrestrial or geographic datasets. The term is normally used in conjunction with geographic information systems and geomatics and never separately.

What is a Geospatial analysis?

Vector-based GIS geospatial analysis typically involves operations such as map overlay (combining two or more maps or map layers in line with predefined rules), simple buffering (identifying regions on a map within a specified distance of one or more features, such as towns, roads or rivers) and similar basic operations. When we use the generic term geospatial analysis, we also include descriptive geo-statistics, such as cell counts, means, variances, maxima, minima, cumulative values, frequencies, and a number of other measures and distance computations.

Raster-based GIS?

For raster-based GIS, widely used in the environmental sciences and remote sensing, this typically means a range of actions applied to the grid cells of one or more maps (or images) often involving filtering and/or algebraic operations (map algebra). These techniques involve processing one or more raster layers according to simple rules, resulting in a new map layer. For example, replacing each cell value with some combination of its neighbours values, or computing the sum or difference of specific attribute values for each grid cell in two matching raster datasets.

Interdisciplinary Science of GIS:

Other very important areas include: surface analysis, in particular analysing the properties of physical surfaces, such as gradient, aspect and visibility, and analysing surface-like data fields network analysis, which involves examining the properties of natural and man-made networks in order to understand the behavior of flows within and around such networks; and location analysis. GIS-based network analysis may be used to solve a wide range of practical problems, such as route selection and facility location (core topics in the field of operations research) and problems involving flows such as those found in hydrology and transportation research. A further important aspect of geospatial analysis is geo-visualisation the creation and manipulation of images, maps, diagrams, charts, 3D views and their associated tabular dataset.

Global Positioning System (GPS) and Satellite Imagery

Global Positioning System (GPS) is a space-based global navigation satellite system that provides reliable location and real time information in all weather conditions, at all times and anywhere on or near the Earth provided there is an unobstructed line of sight to four or more GPS satellites. It The satellites and the system is maintained by the United States government and is freely accessible by to anyone with a GPS receiver.

Remote sensing & satellite imagery

Remote sensing is the small or large-scale acquisition of information on an object or phenomenon, by the use of either recording or real-time sensing device (s) that are wireless, or not in physical or intimate contact with the object (like in the case of aircraft, spacecraft, satellites, buoys or ships). In practice, remote sensing is the use of a variety of devices for gathering information on a given object or area. Earth observation or weather satellite collection platforms, ocean and atmosphere observing weather buoy platforms, the monitoring of a parolee via an ultrasound identification system, Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), X-radiation (X-RAY) and space probes are all examples of remote sensing. In modern usage, the term generally refers to the use of imaging sensor technologies, including: instruments found in aircraft and spacecraft as well as those used in electrophysiology.

A historical overview of the development of GIS

In 1962, the first operational GIS was developed in Ottawa, Canada by Roger Tomlinson of the Canadian Department of Forestry and Rural Development. The system we are using now had emerged by the early 1980s when the Environmental Systems Research Institute (ESRI) and the Computer Aided Resource Information System (CARIS) Computer Aided Resource Information System created a commercial version of GIS. This version combines many of the original basic features with the new techniques of the second generation. The development of GIS techniques has since continued making it an effective and reliable tool for producing easy-to-understand maps.

How does GIS work?

These days, GIS plays a major role as it gathers information from various sources while carrying out different types of tasks. In order to perform these tasks, the data has to be linked to a specific place on Earth due to the use of longitudes and latitudes. For analytical purposes, an additional dataset is overlaid on the map to view the spatial modes and patterns of a specific place. For example, the altitudes of a specific place displayed on the first layer remain visible while checking the environmental changes information on the second layer. GIS can convert geographical data types from raster image to vector to facilitate data analysis and processing. It does so through the establishment of lines around the image cells with the same classification to create a vector of points, lines and polygons, which displays all the required properties on the map.