Advantages of Remote Sensing | disadvantages of Remote Sensing
This page covers advantages and disadvantages of Remote Sensing technology and its basics. It mentions benefits or advantages of Remote Sensing and drawbacks or disadvantages of Remote Sensing. We will understand satellite remote sensing basics including its system elements.
What is Remote Sensing?
• Sensor is the device used for sensing. It consists of optical components and detector which records reflected and/or emitted energy from various objects on the earth.
• Remote sensing is acquiring of data about an object without touching it. Specific satellites are used for this purpose.
• There are two main types of remote sensing satellites viz. passive and active.
• Passive sensing receives emitted EM energy from various objects which is result of sun's reflected energy from them. Based on received energy various measurements have been carried out.
• Active sensing uses EM source which transmits energy towards the Earth and receives reflected energy. Measurements have been carried out these received energy. The figure depicts both active and passive remote sensing types.
• Specific satellites have been developed to perform both passive and active remote sensing.
• Usually in remote sensing system, energy recorded by the on-board satellite sensor have to be transmitted to
a processing station on the earth. Here the received data are processed into image (in hardcopy and/or digital format).
• This processed image is interpreted either visually and/or digitally in order to extract various information about the target characteristics.
• Remote sensing has many applications such as agricultural (e.g. crop identification and estimation, soil study, soil mapping etc.) , Forest mapping, land cover mapping etc.
Benefits or advantages of Remote Sensing
Following are the benefits or advantages of Remote Sensing:
➨Images obtained using remote sensing satellites are used as permanent records which provide useful information in various wavelengths.
➨It can be used for large area coverage analysis and repetitive coverage analysis (e.g. water and agriculture etc.).
➨Data acquisition at various scales and resolutions can be performed with ease which can be processed very fast using a computer in the lab.
➨Passive remote sensing is unobstructive as it records based on EM radiation received from phenomena of interest.
➨It detects natural calamities such as floods or forest fire or volcanic eruption so that immediate rescue operations and planning can be carried out.
Drawbacks or disadvantages of Remote Sensing
Following are the drawbacks or disadvantages of Remote Sensing:
➨The technique is very expensive for small areas requiring one time analysis.
➨Specific training is needed in order to analyze the image data.
➨It is difficult to prepare large scale maps from obtained satellite data.
➨Repetitive aerial photographs are required for analysis of dynamic features. This increases overall cost to the system.
➨The selection of sensors, mounting of sensors, collection of data and its timings are determined by human beings which may lead to errors if care is not taken.
➨Remote sensing equipments require regular calibration, failing to do so will result into uncalibrated remote sensing data.
➨Near by active systems such as radar and laser interferes with the remote sensing system. This affects the phenomenon being analyzed.
➨Certain cases are difficult to be distinguished by the sensor such as artificial grass and natural grass. Infrareed light can distinguish them.
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