EOS 840 Hyperspectral Imaging Applications

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EOS 840 Hyperspectral Imaging Applications
September 15, 2004 Week 3
Ron Resmini v 703-735-3899 ronald.g.resmini_at_boein
g.com Office hours by appointment
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Outline

• One more slide on working in RS
• Review/context/a thread...
• Introduction to radiative transfer theory
• The atmosphere
• Spectral/spatial analysis
• The ENVI s/w system
• My semester project status

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• Conducting your remote sensing career
• Stay current keep abreast of developments in RS
• Know the trends in the field
• Attend conferences/meetings/symposia
• Get involved with the literature
• Write papers/reports...put it in writing
• Always think about fusion with otherdata/informat
  ion sources
• Keep a current CV/resume
• Keep a portfolio of your work
• Be a rebel be rigorously quantitative
• This is actually fairly rare...imho

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Review/Context/A Thread...

• HSI RS is based on the measurement of a physical
  quantityas a function of wavelength its
  spectroscopy
• HSI is based on discerning/measuring the
  interaction oflight (photons, waves) with matter
• A thread from Maxwells equations to...
• Fresnels equations which describe...
• Interaction of EMR with materials
• Ideal, simple configurations of materials
• Ideal, simple conception of RT processes
• No atmoshpere
• View RT as modeling fluxes or radiometric
  quantities
• We want to describe RS within/through an
  atmosphere of...
• Complicated materials, mixtures, real surfaces
• Complicated interactions of EMR within the RS
  scenario

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Review/Context/A Thread...Why?

• We ultimately want to focus on HSI applications
• Many applications are earth RS through/within the
  atmosphere
• Data are collected by sensor systems
• The data are calibrated (spectrally and
  radiometrically)
• Other corrections/fixes may need to be applied
• Apply atmospheric correction (maybe not all the
  time, though)
• Apply information extraction algorithms
• Spectral libraries
• Apply information and/or data fusion
• Apply geometric processing e.g.,
  orthorectification
• Product generation report writing
• Disseminate, publish, archive
• Plan and conduct future data collection and
  exploitation
• Repeathaving learned more from the process!

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Introduction to Radiative Transfer (RT) Theory

• The RT equation (see next slides)
• Simplified expressions get you gt90 of whatyou
  need to know
• Radiometry and radiation propagation
• Coordinates frames of reference principal
  plane, etc.
• Illumination angle, direction
• View angle, direction
• Phase angle
• Azimuth, relative/absolute
• Its easier if we adopt an earth RS scenario
• But...simplified models are very helpful e.g., a
  layerof gas and/or aerosols isolated in space...

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The Radiative Transfer Equation
Eq. 7.21 on pg. 156 of Hapke (1993).
Arghhhhh!!!!
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On the following
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Some Simplified RT Expressions

• RT can be (and in practice is) viewed as an
  accountingof terms based on radiance
  interactions in the RS scenario
• Bear in mind, however, that there is a link
  between theterms in the accounting and solutions
  to the RT equation
• The accountings can be as simple or as
  complicated asnecessary to address the RS
  question(s)/scenario(s)
• i.e., add terms, delete/ignore terms

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Solar/Reflective RS
For a horizontal surface
Now, add a thermal emission term
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The Big Equation
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The Big Equation (continued)
Theres an LI, too its the adjacency effectand
its sometimes included in the LC term.
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• VNIR/SWIR i.e., solar-reflective
• Thermal infrared i.e., emissive
• More later in the semester
• Status check...where are we?
• See slide Review/Context/A Thread...Why?
• We want to get to r or e
• Getting to reflectance (atmospheric compensation)

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The Atmosphere
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Spectral/Spatial Analysis

• Current approaches
• Really rather immaturespectrally
• Edge-detection
• Texture
• The role of the FFT spatially
• HySPADE (Resmini, 2004, in press)
• Excellent discussion in Landgrebe (2003)
• More to be said with the ENVI s/w system
• Applications
• Strategies...

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The ENVI Software System
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My Semester Project

• Use RS data to determine lava tube roof thickness
• Analyze NASA TIMS at Kilauea Volcano
• Six band TIR MSI from 8 to 12 mm
• Archived data from 1988
• Use analytical and numerical solutions to the
  heatequation in conjunction with RS data
• Determine surface temperature over lava tube
• Use modeling to match surface temperature
  anddetermine roof thickness
• Other parameters to consider e.g., h, heat
  transfercoefficient for Newtons law of cooling
  boundarycondition

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On the following
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On the following
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On the following
X 0
X L
Y 0
Y D
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On the following
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My Semester Project Status

• Tools/approach
• Analytical solution(s) to heat equation
• FlexPDE (numerical solution(s) to heat equation)
• ENVI for TIMS data analysis
• Match modeling with data analysis results
• Determine roof thickness
• TIMS data already acquired
• Literature research on going
• Preliminary modeling analyses on-going
• Several FlexPDE models established