323_tech sem slides

7/27/2019 323_tech Sem Slides

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PRESENTED BY: Ruchismita Mahanta [1]

TECHNICAL SEMINAR PRESENTATION 2011

PRESENTED BY

RUCHISMITA MAHANATA Roll # 200750323 (ECE)

Under the guidance of

Mr. Hari Krushna Gantayat

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGYBERHAMPUR,ORISSA

Synthetic Aperture Radar


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Flow Of Discussion

Principles of Radar

Whats SAR?

How does SAR work?

SAR : A type of Imaging Radar

Advantages and Disadvantages

Applications

Conclusion

References


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PRINCIPLES OF RADAR: HOW DOES RADAR WORK?

RADAR = Radio Detection And Ranging

Since radar pulses propagate at the speed of light, the difference to the target

is proportional to the time it takes between the transmit event and reception of

the radar echo.

TRANSMITTER

RECEIVER

CIRCULATOR

RADAR PULSE

"TARGET"


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Whats SAR ?

Synthetic Aperture Radar is a space or airborne

technology that provides high-resolution monitoring for

environmental and military purposes in all weather or

day/night conditions

With SAR it is possible to obtain detailed information

quickly that may be of great use in combating such natural

disasters as wildfires, oil spills, ice and seas, etc.


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How Does SAR Work?

Details are complex, but in a simplified version, we can say

that SAR operates by sending out energy pulses at

microwave wavelengths and measuring the precise time of

the returning echo from a surface

What makes SAR different is that it creates an extremely

sharp beam over a wide area that enables high-resolution

imaging

The next slide represents the process.


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How Does SAR Work?


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SAR is one type of imaging radar


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SAR is one type of imaging radar

Imaging radars produce an image in the flight direction and

for a distance on one side of the flight path


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ADVANTAGES AND DISADVANTAGES

ADVANTAGES:

Operational under all weather conditions with the

capabilities for sensing the earth day and night.

Provides description of surface texture.

Has own source of illumination

Cloud and fog cover are not a problem.

Vegetation and subsurface penetration capabilities.


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ADVANTAGES AND DISADVANTAGES

DISADVANTAGES:

Image distortion Coarse resolution

Extensive shadowing of areas characterised with relief.


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APPLICATIONS

SAR Systems has a wide range of applications such as:

Reconnaissance, Surveillance, and Targeting

Treaty Verification and Nonproliferation

Interferometry (3-D SAR)

Navigation and Guidance

Foliage and Ground Penetration

Moving Target Indication

Change Detection

Environmental Monitoring
http://en.wikipedia.org/wiki/File:Death-valley-sar.jpg


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Conclusion

Synthetic Aperture Radar is now a well established part of radar art, both withairborne systems for surveillance and non-cooperative target identification

purposes, and with space-borne systems for geophysical remote sensing

applications over the oceans, land and polar regions. The capability to operate

under all weather conditions make it an efficient sensor.
http://en.wikipedia.org/wiki/File:Venus_globe.jpg


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References.

Skolnik, M. I., Radar Handbook, McGraw-Hill, New York, 1970.

Curlander, J. C. and R. N. McDounough, Synthetic Aperture Radar, Systems

and Signal Processing, John Wiley & Sons, New York, 1991

http://en.wikipedia.org/wiki/Synthetic_aperture_radar

http://www.radartutorial.eu/20.airborne/ab07.en.html
http://en.wikipedia.org/wiki/Synthetic_aperture_radarhttp://en.wikipedia.org/wiki/Synthetic_aperture_radarhttp://en.wikipedia.org/wiki/Synthetic_aperture_radarhttp://en.wikipedia.org/wiki/Synthetic_aperture_radarhttp://en.wikipedia.org/wiki/Synthetic_aperture_radarhttp://en.wikipedia.org/wiki/Synthetic_aperture_radarhttp://en.wikipedia.org/wiki/Synthetic_aperture_radarhttp://en.wikipedia.org/wiki/Synthetic_aperture_radar


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Questions?

Suggestions?Other Remarks?


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