Registration and layer stacking using ENVI software

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• Registration and layer stacking using ENVI
  software
• by
• JWAN AL-DOSKI
• Universiti Putra Malaysia

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Introduction to RazakSAT

• RazakSAT is Malaysia's remote sensing
  satellite launched from Kwajalein Atoll, an
  island located in the Republic of the Marshall
  Islands, U.S.A. on July 14, 2009 using a Falcon 1
  launcher developed by SpaceX. RazakSAT is a small
  Low Equatorial Orbit (LEO) and carries the
  electro-optical payload of a Medium-sized
  Aperture Camera (MAC) - a pushbroom camera with 5
  linear detectors (1 panchromatic, 4
  multi-spectral).

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Fig. RazakSAT
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List of Countries Covered by RazakSAT
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RazakSAT bands

• RazakSAT has visible and near infrared
  wavelength (VNIR), including four multispectral
  bands from 450nm 890nm and one panchromatic band
  from 510nm to 730nm. Its ground pixel resolution
  is 5m for multispectral bands and 2.5m for
  panchromatic band. At 685km nominal altitude, the
  image swath width for MAC is 20km. It provides a
  high number of passes (14 times per day over
  Malaysia).

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As we can see here, the data loaded in RGB
composition but all three bands could not match
or display correctly.
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Methodology
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1- Spectral subsetting
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Band 1 Band2
Band3 Band4
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2-Registration
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what is registration?

• Registration is referencing images to geographic
  coordinates and/or correcting them to match base
  image geometry

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Base (reference)
Image Warp Image
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Registration methods in ENVI software

• Image-to-Image Ground Control Points .
• Image-to-Map Ground Control Points .
• Automatically Co register Images .
• Warp from GCPs Image-to-Image.
• Warp from GCPs Image-to-Map.

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Warping ,ENVI offers three warping methods and
1. RST. 2.Polynomial.3.Delaunay triangulation
Re sampling ,ENVI offers three methods 1.
nearest neighbour2. bilinear.3. cubic
convolution
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Nearest neighbour as a resample method used
RST as a warp method used

• RST Rotation, scaling, and translation this is
  the simplest method. To perform RST warping, you
  need three or more GCPs. The RST warping
  algorithm uses an affine transformationx a1
  a2X a3Yy b1 b2X b3Y

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Image-to-Map Ground Control Points for band 1
base on Google earth
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Base on band1 (band2,3,4) had warped using
Image-to-Image Ground Control Points
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4- layer stacking
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Layer stacking parameters and map projection
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Layer stacking band 1, 2, 3
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The second image is from layer stacking using
Automatically Co-register Images composition 1,2,3
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Thank you