Radar Remote Sensing and Agricultural Science

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Radar Remote Sensing and Agricultural Science

• By Falah FakhriVisitor researcher
• falah.fakhri_at_utu.fi falah.atta_at_gmail.com
  https//www.researchgate.net/profile/Falah_Fakhri
  https//falahfakhri.wordpress.com Department
  of Agricultural Science

Thursday 11.02.2016 Time 1400 1600
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Seminars outlines

• ? Theoretical
• ? Passive and active Remote Sensing 3/3
• ? Active Remote Sensing 3/3
• ? Scattering Mechanisms 3/3
• ? Geometry of imaging radar system 5/5
• ? Amplitude and phase 4/4
• ? Polarization 3/3
• ? Ascending and Descending 1/1
• ? Historical Analysis 1/1
• ? Practical
• ? SNAP and Hardware 3/3
• ? SNAP Environment and Tools 10/10

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Passive and active Remote Sensing 1/3

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Passive and active Remote Sensing 2/3
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Passive and active Remote Sensing 3/3
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Active Remote Sensing 1/3
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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Active Remote Sensing 2/3
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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Active Remote Sensing 3/3
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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Scattering Mechanisms 1/3
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Scattering Mechanisms 2/3
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Scattering Mechanisms 3/3

• ? Surface Roughness
• Back-scattering increases with roughness
• ? Moisture content
• Back-scattering
• increases with moisture
• ? Topography
• Viewing geometry
• affects the signal

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Geometry of imaging radar system 1/5
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Geometry of imaging radar system 2/5
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Geometry of imaging radar system 3/5
SENTINEL-1 Product Modes
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Geometry of imaging radar system 4/5
TOPSAR Sub-Swath Acquisition
TOPSAR technique to acquire data over a much
wider area
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Geometry of imaging radar system 5/5
IW Sub-Swaths with Minimal Overlap
After de-bursting and merging the sub-swaths
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Amplitude and phase 1/4

• Amplitude values represent the radar backscatter
  the brighter the pixel, the stronger the
  backscatter.
• Phase values is related to the sensor-to-target
  distance and the interaction of the e.m. signal
  with the radar target

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Amplitude and phase 2/4
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Amplitude and phase 3/4
Phase
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Amplitude and phase 4/4
Intensity
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Polarization 1/3
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Polarization 2/3
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Polarization 3/3

• Across-Polarization VH/HV
• Co-Polarization HH/VV
• Single polarization (HH or VV)
• Dual polarization (HHHV or VVVH),
• Across-Polarization VH/HV lt PENTRATED Than
  Co-Polarization HH/VV
• HH are preferred for Soil Moisture

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Ascending and Descending 1/1
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Historical analysis 1/1
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SNAP and Hardware 1/3

• ? What does the acronym SNAP stand for?
• SNAP is the SeNtinels Application Platform.
• ? What is the minimum required hardware to run
  SNAP on a laptop or desktop?
• It is recommended to have at
  least 4GB of memory. To run the 3D WorldWind
  View, it is recommended to have a 3D graphics
  card with updated drivers. SNAP will work on 32
  and 64 bit Windows, Mac OS X and Linux.

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SNAP and Hardware 2 /3
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SNAP and Hardware 3/3

• This is due to memory. You could try two things.
• ? First, go to the options dialog in the tools
  menu. In the S1TBX tab, check use file cache to
  conserve memory. Try your processing again.
• It might be slower if you don't have an SSD but
  it may processes.
• If that still doesn't work,
• Second, Try changing the setting in the
  performance tab. They should default to something
  optimal for your system but you never know... Too
  many things can affect memory depending on what
  other applications are doing.

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SNAP Environment and Tools 1/10
Desktop Icon
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SNAP Environment and Tools 2/10
Image View
Navigate tool window
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SNAP Environment and Tools 3/10
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SNAP Environment and Tools 4/10
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SNAP Environment and Tools 5/10
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SNAP Environment and Tools 6/10
Helsinki
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SNAP Environment and Tools 7/10
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SNAP Environment and Tools 8/10
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SNAP Environment and Tools 9/10
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SNAP Environment and Tools 10/10
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Kiitos paljon, Tervetuloa
uudelleen Kysymykset
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