23 February 2010

Remote Sensing and Geographic Information System

We normally observe the earth from a more or less horizontal viewpoint while living on its surface. From an altitude or from a vertical perspective, our impression of the surface below is notably different. Remote sensing enables us to view the spectral and spatial relations of observable objects and materials at a distance, typically from above, using instruments or sensors. Remote sensing is most often practised from platforms such as airplanes and spacecrafts with onboard sensors that survey and analyse surface features over extended areas unencumbered by the immediate proximity of the neighbourhood. It is a practical, orderly, and cost-effective way of maintaining and updating information about the world around us.

The advancements in computer-based image processing have made robotic and manned platform observations accessible to universities, resource-responsible agencies, environmental companies, and even individuals in their personal computers. Initially, remote sensing was controlled and sponsored by the governments of various countries but recently, commercial vendors have also involved themselves in this emerging field.

Geographical Information System (GIS) is a computer-assisted information management system of geographically referenced data. A GIS differs from conventional computer-assisted mapping and attribute data analysis systems. Although computer-assisted cartographic systems emphasize map production and presentation of spatial data, they cannot analyse spatially defined attribute data. Attribute data analysis systems, on the other hand, analyse aspatial data. A GIS blends these into a more powerful analytical tool. Its proponents highlight its capacity to produce a comprehensive and timely analysis of complex database and its potential to improve data collection, analysis, and presentation process. Today, it is possible to make conventional GIS over the Internet, sharing various data for the use of the whole world. From the perspective of information science, the growing interest in GIS is fascinating.

GIS provides an exceptional means for integrating timely remote sensing data with other spatial and thematic data types. It is a concept that originated in Canada four decades ago, is now being applied by several application sectors as the demand increases for information and analysis on the relationship between people and their environment. Now that many commercially available GIS software packages are becoming increasingly user friendly, and can be run on personal computers, this important tool is being actively explored all over the world for various applications.

Remote sensing and GIS were initially recognized as supporting tools for planning, monitoring, and managing the appropriate utilization of earth resources. However, due to their multidisciplinary applications and integration with numerous other scientific and technological fields, in the recent years they have become a distinct field of study.

The rapid progress, and increased visibility, of remote sensing and GIS since the 1990s has been made possible by a paradigm shift in computer technology, computer science, and software engineering, as well as airborne and space observation technologies. As a result a new field of study named geomatics engineering or geospatial technology or geoinformatic technology is now in its maturity. The term 'geomatics' is fairly young and is commonly used to define the tools and techniques used in land surveying, remote sensing, GIS, global navigation satellite systems (GNSS), and related forms of earth mapping.

Beginners in this emerging field may refer my book Remote Sensing and GIS

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