Remote Sensing and GIS has become beneficial, exciting glamorous due to different upcoming opportunities and nowadays it is useful in our day to day life.
Question comes in our mind is that, why GIS fields are important currently, two main reasons behind this are. 1) Currently everybody including scientists, researchers, students, and even common people are showing great interest for better understanding of our environment & processes in it. Environment refers to geographic space and the events that happen there. In different ways, we notice that geographic space along with the data denoting it, is part of our world; many decisions we take which are influenced by fact of geographical world. 2) Advancement in GIS & RS i.e. Geoinformatics stream (which can provide large volume of spatial data i.e. geographic data, with minimum costs of computer hardware and software has made Remote Sensing and G.I.S. affordable to not only complex geospatial situation but also affordable to increasingly varied individuals.
RS (Remote Sensing):
Remote sensing is the science of measurements of objects from distance apart,without coming into physical contact with the objects under study. In another way, remote sensing is the collection of data and deriving information about objects materials (targets) located at the earth’s surface or in its atmosphere by using sensors(mostly multi-spectral) mounted on the platforms located at distance from the target to make measurements of interactions between the target and electromagnetic radiation.
Important components of remote sensing technology are data procurement, data processing and analysis. The devices used in the process to detect electromagnetic radiation (EM) are called sensors. The measurement of EM energy is done in different wavelength bands depending upon the application.
The sensors are of two types, one uses external energy source (i.e. passive sensor) and other uses its own source (i.e. active sensor). The principal source of energy for passive remote sensing is sun. Before the solar radiation reaches the earth it passes through the whole thickness of the atmosphere. The atmosphere has limited transparency in certain parts of EM spectrum and hence is not suitable for remote sensing. The wavelength bands for which the atmosphere is transparent is called atmospheric window.
The solar radiation which reaches the earth surface interacts with objects. As a result physical phenomenon like reflectance, absorption, emission and transmission take place. The energy interaction is often precise (specific) for an object and is defined as spectral signature. The specificity of signature may be used for distinguishing object or for determining certain characteristics of an object. Since under natural conditions the object may be similar but not necessarily identical, therefore signature will also not be unique. What we detect is the spectral response pattern instead of signatures.
The passive remote sensing techniques are mainly concerned with the detection and measurement of optically reflected and/or emitted radiation from the objects. The radiation passes through the atmosphere, before reaching the sensor, which may result modify the radiation coming from the earth surface. These atmospheric effects mainly depend on the atmospheric conditions i.e. hazy, cloudy climate, etc. and the wavelength bands used.
The result efficiency of this technology for certain application depends upon the spectral response pattern of the scene, atmospheric conditions and the capability and capacity of the sensor which is expressed in terms of spatial, spectral, radiometric and temporal resolutions.
Geographical Information System (GIS)
GIS is a powerful set of tools for assimilating, storing, retrieving, transforming, converting, presenting and displaying spatial and non-spatial data from the real world. It has the ability to assimilate divergent sources of data both spatial (i.e. data related to space-geographical data) and non-spatial (i.e. attribute data). Geographic information system allows the user to integrate database generated from various sources as single platform and analyze them efficiently in a spatio-temporal domain. GIS technology forms combination of cartography, statistical analysis and computer technology. Geographic information system provides support in resource management, decision making and many more streams.
GIS is widely implemented technology – Characteristics of GIS:
- Advance technologies of Remote Sensing and GIS as a powerful tool for spatial analysis.
- Computerization of the spatial data.
- It reduces the time and cost in organizing the data in data center.
- It provides efficient methods for analysis of land use issues and tools for land use planning and modeling.
- GIS is broadly available through internet. And accessible with organization wide local area networks
- Easily availability of low-cost, locational based, hand-held devices. Ex PND used for navigation (PND- Personal Navigation Device)
- Fast growing market for GIS due to easily availability of software and hardware with low expenditure.
- Greater awareness among all due to decision making and planning has a geographic dimension.
- GIS supports user interactions by using standard windowing environments.
- Technology supports to visualization, data management and data analysis, and also having capability to link with other softwares.
- GIS technology can provide georeferenced digital data which is generated by using GPS technology. Also it supplied by value-added resellers (VARs) of data. Locational reference is key feature of this techniques.
- Availability of open-source, free to use software across the Web. So advance GIS solutions that are ready to run out of the box.
- GIS applications are useful in numerous fields & sectors.
- GIS technology is capable of making a tremendous impact on all planning, management & strategic decision making activity.
- It provides a wonderful opportunity to the private & public sector for generation of valuable, useful & cost effective applications.
GIS and RS technology useful in following applications
- Disaster management and hazard zone mapping.
- Land use planning
- Weather forecasting
- Property tax mapping & management
- Water supply system management
- Solid waste management
- Land Record management
- Sewerage System Management
- Urban Planning & Town planning
- Traffic control & Road management
- Navigation Projects
- Electricity mapping etc…
GIS & RS technology is beneficial in various applications which has a tremendous scope and finally it only helps to ease human life.