Skip to main content

Terminology. Remote Sensing

Absorptance : The ratio of the radiant energy absorbed by a substance to the energy
it receives.

Band : The specific wavelength interval in the electromagnetic spectrum.

Digital image : An array of digital numbers (DN) arranged in rows and columns,
having the property of an intensity value and their locations.

Digital Number : An intensity value of a pixel in a digital image.

Digital Image Processing : The numerical manipulation of DN values for the purpose
of extracting information about the phenomena of the surface they represent.

Electromagnetic Radiation (EMR) : The Energy propagated through a space or a
medium at a speed of light.

Electromagnetic Spectrum : The continuum of EMR that ranges from short wave
high frequency cosmic radiations to long wavelength low frequency radio waves.

False Colour Composite (FCC) : An artificially generated colour image in which
blue, green and red colours are assigned to the wavelength regions to which they do
not belong in nature. For example, in standard a False Colour Composite blue is
assigned to green radiations (0.5 to 0.6 µm), green is assigned to red radiations (0.6
to 0.7 µm and red is assigned to Near Infrared radiation (0.7 to 0.8 µm).

Gray scale : A medium to calibrate the variations in the brightness of an image that
ranges from black to white with intermediate grey values.

Image : The permanent record of a scene comprising of natural and man-made
features and activities, produced by photographic and non–photographic means.

Scene : The ground area covered by an image or a photograph.

Sensor : Any imaging or non–imaging device that receives EMR and converts it into
a signal that can be recorded and displayed as photographic or digital image.

Reflectance : The ratio of the radiant energy reflected by a substance to the energy
it receives.

Spectral Band : The range of the wavelengths in the continuous spectrum such as
the green band ranges from 0.5 to .6 µ and the range of NIR band 0.7 to 1.1 µ.




Comments

Post a Comment

Popular posts from this blog

The global dimensions of disaster

Disasters are not merely natural occurrences but complex interactions between natural hazards and human vulnerabilities. To effectively address disaster risk, we must consider several interconnected dimensions: 1. Vulnerability: Definition: The susceptibility of individuals, communities, or assets to harm from a disaster. Factors: Socioeconomic conditions, geographic location, and environmental factors influence vulnerability. Example: Communities with high poverty rates and limited access to resources are more vulnerable to disaster impacts. 2. Exposure: Definition: The degree to which people, property, and infrastructure are located in hazard-prone areas. Factors: Population density, land use patterns, and infrastructure development influence exposure. Example: Coastal cities with high population density are highly exposed to hurricane and tsunami risks. 3. Capacity: Definition: A community's ability to prepare for, respond to, and recover from disasters. Factors: Strong ...
Post a Comment
Read more

Overview of Disasters in India

India's Vulnerability to Natural Disasters India's diverse geography and climate make it highly susceptible to a range of natural disasters. These events, including earthquakes, tsunamis, floods, droughts, cyclones, and landslides, can have devastating consequences for millions of people and the economy. Major Natural Disasters Affecting India: Earthquakes: Tectonic Setting: India's position on the Indian Plate, which is colliding with the Eurasian Plate, makes it prone to seismic activity. Impact: Earthquakes can cause widespread destruction, including building collapses, landslides, and tsunamis. The 2001 Gujarat earthquake is a prime example of such devastation. Tsunamis: Oceanic Triggers: Underwater earthquakes and volcanic eruptions can generate tsunamis, as seen in the 2004 Indian Ocean Tsunami. Impact: Coastal areas are particularly vulnerable to tsunamis, which can lead to massive loss of life and property. Floods: Monsoon Influence: India's...
Post a Comment
Read more

Water Act 1974

The Water (Prevention and Control of Pollution) Act of 1974 is a significant piece of legislation in India aimed at preventing and controlling water pollution. Here are some key facts about the Act: 1. Objective: The primary objective is to prevent and control water pollution and maintain or restore the wholesomeness of water in the country. 2. Establishment of Boards:    - Central Pollution Control Board (CPCB): The Act mandates the establishment of the CPCB to oversee and coordinate activities across the nation and advise the Central Government.    - State Pollution Control Boards (SPCBs): Each state is required to establish its own SPCB to plan comprehensive programs for the prevention and control of pollution. 3. Powers and Functions:    - The Boards have the authority to inspect any sewage or trade effluents, works, and plants for the treatment of sewage and trade effluents.    - They can establish standards for the discharge of pollutants into water bodies and ensure adherence to...
Post a Comment
Read more

Environment Management DRR

Environmental management plays a crucial role in disaster risk reduction (DRR) by harnessing the power of natural ecosystems to prevent and mitigate the impacts of disasters. By protecting and restoring these ecosystems, we can strengthen community resilience and promote sustainable development. Interconnections Between Environmental Management and DRR: Ecosystem-Based Disaster Risk Reduction (Eco-DRR): Natural Barriers: Ecosystems like forests, wetlands, and coral reefs act as natural barriers, reducing the impact of hazards like floods, landslides, and storm surges. Resilience Building: Healthy ecosystems enhance community resilience by absorbing excess rainfall, preventing erosion, and mitigating the effects of climate change. Environmental Considerations in Disaster Planning: Sustainable Practices: Incorporating environmental considerations into disaster planning helps prevent further environmental degradation, which can exacerbate disaster impacts. Resource Conservati...
Post a Comment
Read more

Forset management and water conservation

Forest management and water conservation are closely intertwined concepts, as forests play a crucial role in maintaining water resources. Here's an explanation of their connection: 1. Water Regulation: Forests act as natural sponges, absorbing rainwater and releasing it gradually. Trees help regulate water flow, preventing rapid runoff and reducing the risk of floods. 2. Groundwater Recharge: Trees contribute to groundwater recharge by allowing rainwater to percolate into the soil. This replenishes underground aquifers, which are important sources of freshwater. 3. Erosion Control: Forests provide vegetation cover that protects soil from erosion caused by rainfall. This, in turn, helps maintain the quality of water bodies by preventing sedimentation. 4. Streamflow Maintenance: Healthy forests ensure consistent streamflow. Trees release water through transpiration, influencing local and regional precipitation patterns and sustaining rivers and streams. 5. Biodiversity and Water Qual...
Post a Comment
Read more