1. Radar Remote Sensing By Falah Fakhri Post-doctoral Scholar falah
Radar Remote Sensing By Falah Fakhri Post-doctoral Scholar ‎ Department of Geography and Geology
Tuesday 26/08/2014 Time: 14:00 – 15:00
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2. • Passive and active Remote Sensing • Concept of Radar
Seminar’s outline
• Passive and active Remote Sensing
• Concept of Radar
• Concept of SAR
• Optical Image Format and Characteristics
• SAR Image Format and Characteristics
Amplitude
Phase
• Images acquisitions
• Software's are used in SAR (Radar Images Processing)
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3. Passive and active Remote Sensing 1/1
Passive vs. Active Sensors
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4. where objects are in space.
Concept of Radar (1/10)
Echolocation
is the use of
sound waves and
echoes to determine
where objects are in space.
Bats use echolocation to navigate and find food in the dark. To echolocate, bats send out sound waves from their mouth or nose. When the sound waves hit an object they produce echoes. The echo bounces off the object and returns to the bats ears. Bats listen to the echoes to figure out where the object is, how big it is, and its shape.
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5. Concept of Radar (2/10)
Imagine you are in the Grand Valley and you shout. The cliffs will reflect the sound wave. After some time you will hear an echo, which is not exactly the same compared to what you shouted. This is the “principle” of a radar!
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6. RADAR stands for Radio Detection and Ranging … so what is a Radar?
Concept of Radar (3/10)
RADAR stands for Radio Detection and Ranging … so what is a Radar?
A: (Imaging) Radar is an active system that uses a transmitter to illuminate a scene. The pulses sent are microwaves, i.e. a wave with an amplitude and a phase, having a certain frequency and polarization.
The radar then records the echo or
(backscatters)
scattered back from the objects/targets
B: Non imaging
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7. Concept of Radar (4/10)
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8. radars illuminate the target so that they • can operate day and night.
Concept of Radar (5/10)
radars illuminate the target
so that they
• can operate day and night.
• Microwave frequencies
Electromagnetic
waves penetrate to
Some extent through media.
• At most frequencies clouds are
transparent!
• Complex interaction with medium or
target:
a “Radar image” is not a photo!
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9. Concept of Radar (6/10) Passive Remote sensing Active Remote Sensing
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10. Concept of Radar (7/10) interaction with medium or targets
The transmitted pulse interacts
with the Earth surface
and only a portion
of it is backscattered to the
receiving antenna
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11. Interesting, right?
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