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you might found ppt about remote sensing easily but this is perticularly made about remote sensors.. it includes it all types like active and passive sensor..
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Department of Mechanical Engineering
Subject:- Remote Sensor…
What is Remote Sensor ??
Remote Sensors are the device that measures the properties of electromagnetic radiation leaving a medium due to scattering or emmision…
Types of Remote Sensor..
There are to types of Remote sensore
1. Passive Sensor
2. Active Sensor
now let’s take a look at there types in detail….
Passive Sensors…
It senses natural radiation which is either emmited or reflected from the target
The sun’s energy is either reflected , as it is visible wavelengths or absorbed and then re-emitted as it is for thermal infrared wavelengths.
Passive sensors only be used to detect naturally occuring energy.
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there is no reflected energy available from sun at night.
The amount of solar radiation present at polar latitude is often insufficient for visible light sensors limiting the use of passive sensor to lower latitude.
The problem associated with passive remote sensing can be overcome by designing a remote sensing system in which a sensor can be used that is capable of detecting radiation in several different portion of the electromagnetic spectrum.
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For example, by using a combination of visible and thermal infrared channel, whether satellites can provide imagery of the earth’s cloud patterns during both day and night hours.
Similarly Thermal Mapper is a good example of the Passive Sensor, this sensor has seven band or channel
Examples….
Active Sensor…
The sensors which produces its own electromagetic radiation of a specific wavelengths and the interactionof this radiation with the target is studied for target identification are called active sensors.
It is the direct burst of radiation at the target and use sensors to measure.
Most often the sensor detects the reflection of the energy, measuring the angle reflection or the amount of it took for the energy to return.
It provide the capability to obtain measurements any time, regardless of the time of the day or season.
Countinue….
Synthetic Aperture Radar (SAR) is one of the best example of an active remote sensing technology.
Doppler radar is another example of an active remote sensing technology.
A sensor measure the reflection or echos of this energyoff such atmospheric particle
Example….
