Types of Remote Sensing| Class 11 Geography Notes

Class 11 Geography Notes: Achieving success in CBSE exams requires a clear understanding of Geography concepts. Thus, Class 11 students must obtain well-structured Geography Class 11 Notes from experienced teachers. These notes are designed to help students understand the fundamental concepts of Geography and build a strong foundation for their future studies.

Our Geography Notes for Class 11 are a helpful resource to improve problem-solving skills and prepare for Social Science Class 11 exams. By using our detailed notes, students can strengthen their understanding of Geography and become better at solving problems.

Types of Remote Sensing| Class 11 Geography Notes

What is Remote Sensing?

Remote sensing is a technology that gathers information about the Earth’s surface without making direct contact. It involves sensing and recording energy reflections or emissions, and then processing, analyzing, and using that data. Special cameras are used to collect images from objects on Earth, which are then analyzed to provide information about the planet.

In simple terms, remote sensing is about gathering information from objects on Earth using satellites. It involves recording energy reflections or emissions and then analyzing and applying that information.

There are many remote sensing satellites launched by various countries, such as the Indian Remote Sensing Satellite (IRS), Sputnik 1 from Russia, and Explorer 1 from the USA. These satellites help measure the radiation emitted and reflected by different regions, enabling scientists to monitor the Earth’s physical properties from afar.

For instance, sonar equipment on ships can capture images of the seafloor without diving into the ocean. Remote sensing can track changes in agriculture, forests, and urban areas over time, providing valuable insights for various purposes.

Types of Remote Sensing

Remote sensing refers to the technology of gathering information about the Earth’s surface without direct physical contact. There are two main types of remote sensing:

1. Passive sensors
2. Active sensors

Passive Sensors

Passive sensors detect natural energy (radiation) emitted or reflected by the object or scene being observed. The most common source of radiation measured by passive sensors is reflected sunlight. In contrast, sensing done via active sensors is called active sensing, for which they often require additional electrical power for excitation. Passive sensors can only detect the energy that naturally occurs, and they gather data during the day when electromagnetic energy is available.

Unlike active sensors, passive sensors do not emit energy and instead wait for data requests. They are vulnerable to external disturbances. The transducer of a passive sensor causes a change in a passive electrical quantity such as capacitance, resistance, or inductance as a result of the stimulation.

Passive sensors measure using electromagnetic radiation that is naturally emitted within their field of view. Examples of passive sensors include satellites used for remote sensing, such as SPOT-1 and LANDSAT-1.

Active Sensors

Active sensors transmit their own signal and measure the energy that is reflected, transmitted back, or scattered back from the target. Examples include radar and sonar. Sensing done via passive sensors is called passive sensing. An active sensor’s transducer directly produces electric current or voltage in response to external stimulus. It generates its own electromagnetic (EM) energy, sends it toward the Earth, and then collects the energy reflected back from the planet. Electromagnetic (EM) radiation received is used for measurement.

Active sensors can self-destruct during hijack attempts and can take measurements at any time. They measure and transmit electromagnetic energy. Unlike passive sensors, active sensors actively communicate measurements to ground stations regardless of whether the on-duty employees want the data or not. They provide their own energy source for illumination. Examples of active sensors include communication satellites, earth observation satellites, and LISS-1.

Conclusion

Remote sensing involves two main types: passive and active sensing. Passive sensors detect natural energy, like sunlight, while active sensors emit their own signals and measure the energy reflected back.

Both methods are vital for gathering information about Earth’s surface, aiding in tasks like monitoring the environment and planning cities. Understanding these methods helps in using remote sensing effectively for various purposes.

Related Links

1. CBSE Class 9 Geography Revision Notes
2. CBSE Notes Class 10 Geography Chapter 1- Resources and Development
3. CBSE Class 10 Geography Notes Chapter 3 : Water Resources
4. CBSE Notes Class 10 Geography Chapter 4 – Agriculture

FAQs on Class 11 Geography Types of Remote Sensing

What is remote sensing?

Remote sensing is the process of acquiring information about an object, area, or phenomenon from a distance from satellites or aircraft, without making physical contact.

What are the different types of remote sensing?

There are two main types of remote sensing: passive remote sensing and active remote sensing.

How does passive remote sensing work?

Passive remote sensing detects natural energy (radiation) emitted or reflected by the object being observed, such as sunlight. Sensors measure this radiation without emitting their own energy.

How does active remote sensing work?

Active remote sensing involves sensors that transmit their own signal towards the Earth’s surface and measure the energy reflected or scattered back. Examples include radar and sonar.

What are the applications of remote sensing in geography?

Remote sensing has various applications in geography, including land cover mapping, urban planning, environmental monitoring, agriculture, disaster management, and resource exploration.