Table of Contents
Remote sensing may be defined as a science and technology by which the properties of selected objects, areas, or phenomena can be determined, measured, and analyzed without direct contact to create practical judgments. There are 2 types of remote sensing.
The uses of remote sensing contain land-use mapping, weather forecasting, environmental study, natural hazards study, and resource investigation.
1. Principle of Remote Sensing
The remote sensing data origin is the electromagnetic radiation radiated or reflected by the object, which allows their identification and classification.
2. Components of Remote Sensing
The components of remote sensing are as follows:
a. Platform
A Platform is described as a carrier for remote sensing sensors. There are three primary remote sensing platforms that are as follows:
a. Ground-level platforms (towers and cranes)
b. Aerial platforms (Helicopters, low-altitude aircraft, high-altitude aircraft)
c. Spaceborne platforms (space shuttles, polar-orbiting satellites, and geostationary satellites).
b. Sensors
It is an instrument that acquires electromagnetic radiation and transforms it into a signal that can be recorded and shown as numerical data or an image.
Elements Involved in Remote Sensing
a. Energy Source or Illumination (A)
b. Radiation and the Atmosphere (B)
c. Interaction with the Object (C)
d. Recording of Energy by the Sensor (D)
e. Transmission, Reception, and Processing (E)
f. Interpretation and Analysis (F)
g. Application (G)
3. Types of Remote Sensing Systems
There are mainly two types of remote sensing that are as follows:
a. Active Sensing
b. Passive Sensing
a. Active Sensing
Active sensors radiate energy in the state of electromagnetic radiation towards the mark and calculate the reflected or scattered energy. The energy can be in the state of microwaves, radio waves, or laser beams. Active sensors develop their own energy and radiate it towards the mark, and then calculate the energy that is reflected or scattered back.
b. Passive Sensing
Passive sensors do not radiate energy toward the target but calculate the natural energy reflected or radiated by the mark. The energy can be in visible light, infrared radiation, or thermal radiation. Passive sensors calculate the energy naturally radiated or reflected by the mark.
The other types of Remote sensing are as follows:
a. Visual Remote Sensing Systems, such as the human visual system
b. Optical Remote Sensing
c. Infrared Remote Sensing
d. Microwave Remote Sensing
e. Radar Remote Sensing
f. Satellite Remote Sensing
g. Airborne Remote Sensing
h. Acoustic and near-acoustic remote sensing
4. Basic Processes in Remote Sensing
The basic processes applied in Remote sensing are as follows:
a. Data acquisition (energy propagation, platforms)
b. Processing (conversion of energy pattern to images)
c. Analysis (quantitative and qualitative analysis)
d. Accuracy assessment (radiometric and geometric correction)
e. Information distribution to users
5. Remote Sensing Applications
1. Land Use Mapping
Remote sensing data assists in obtaining up-to-date land use patterns of big sites at any given time and monitoring modifications that happen occasionally.
It can modernize road maps, asphalt conditions, and wetland delineation.
Regional planners and administrators employ the information to develop policies that encourage the area’s overall development.
2. Weather Forecasting
Remote sensing is broadly employed in India for the use of weather forecasting. It is even employed to alert people about upcoming cyclones.
3. Environmental Study
It can be utilized to study deforestation, degradation of fertile lands, pollution in the atmosphere, desertification, eutrophication of big water bodies, oil spillage from oil tankers, etc.
4. Study of Natural Hazards
Remote sensing can be employed to analyze harms induced by earthquakes, volcanoes, landslides, floods, and melting of ice in polar parts. Multiple times remote sensing will assist in forecasting the occurrence of natural hazards.
5. Resource Exploration
Remote sensing data asset update existing geological maps, rapidly organize lineament and tectonic maps, specify the minerals’ quarrying sites, and locate fossil fuel deposits.
6. Advantages of Remote Sensing
The advantages of Remote sensing are as follows:
1. Remote sensing permits coverage of very big regions, encouraging regional surveys on different themes and identification of significantly prominent features.
2. Remote sensing permits repetitive coverage, which arrives handy when gathering data on dynamic themes such as water, agricultural fields, etc.
3. Remote sensing permits accessible data collection over different scales and resolutions.
4. A single image captured through remote sensing can be investigated and analyzed for different uses and goals. There is no boundary on the extent of data that can be collected from a single remotely sensed image.
5. Remotely sensed data can fastly be processed and investigated employing a computer, which can be employed for different uses.
6. Remote sensing is open, primarily if the sensor passively records the electromagnetic energy reflected or radiated by the phenomena of interest. This signifies that passive remote sensing does not trouble the object or the zone of interest.
7. Information gathered through remote sensing is investigated at the laboratory, which minimizes the work required on the site.
8. Remote sensing permits map revision at a small to medium scale, making it cheaper and faster.
9. Color composite can be acquired or produced from three separate band images, assuring the area’s details are far more described than when only a single band image or aerial photograph is reproduced.
10. It is more comfortable to find floods or forest fires distributed over a big area, making it more comfortable to design a rescue mission smoothly and quickly.
11. Remote sensing is a fairly cheap and constructive method of reconstructing a base map without detailed land survey techniques.
7. Disadvantages of Remote Sensing
The disadvantages of Remote sensing are as follows:
1. Remote sensing is a moderately expensive analysis technique, primarily when calculating or surveying shorter zones.
2. Remote sensing needs special training to explore the images. It is, therefore, expensive in the long run to employ remote sensing technology since additional training must be accorded to the technology consumers.
3. It is costly to examine repetitive photographs if it is essential to investigate various elements of the photography features.
4. It is humans who choose what sensor requires to be employed to gather the data, set the resolution of the data and calibration of the sensor, choose the platform that will maintain the sensor, and decide when the data will be gathered. Because of this, it is more comfortable to instruct human error in this type of analysis.
5. Active remote sensing systems, such as radars that radiate electromagnetic radiation, can be effective but intrusive and may hold an impact on the investigated phenomenon.
6. The mechanisms employed in remote sensing may occasionally be un-calibrated, directing to un-calibrated remote sensing data.
7. Various phenomena being investigated may sometimes examine the same during measurement, directing to classification blunders.
8. The image being investigated may occasionally be interfered with by other phenomena not being calculated, which should also be considered during analysis.
9. Remote sensing technology is occasionally oversold to the point where it handles like a panacea that will deliver all the solutions and information for leading physical, biological, or scientific research.
10. The information delivered by remote sensing data may not be all-out or temporary.
11. At times, satellite data cannot deliver full remote sensing data collection, creating it impossible to develop large-scale engineering maps.
This was for the Types of Remote Sensing.
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