Satellite Thermal Remote Sensing of Boiling Springs Lake Jeff Pedelty NASA Goddard Space Flight Center Goddard Center for Astrobiology

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Satellite Thermal Remote Sensing of Boiling
Springs LakeJeff PedeltyNASA Goddard Space
Flight CenterGoddard Center for Astrobiology
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Overview

• Work in progress
• Description of sensors
• Landsat 7s ETM
• TERRAs ASTER
• Acquisitions of Boiling Springs Lake
• Temperature determinations issues
• Future aerial thermal remote sensing

ASTER October 19, 2002
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Landsat 7 ETM

• Landsat 7 launched April 1999
• ETM is the Enhanced Thematic Mapper Plus
• 16-day repeat cycle
• 15 duty cycle
• Conterminous US imaged each overpass
• Approximately 1030AM acquisition
• Single thermal band (10.4-12.5?)
• 60m spatial resolution across 185km area
• Data purchased from USGS EROS Data Center (250
  for new acquisitions, 600 lt 5/31/2003)

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Landsat 7 acquisitions of BSL

• Goal was to acquire seasonal sampling at
  reasonable cost
• Scan Line Corrector failure in May 2003
  introduced luck into acquisition process
• Jan 12, 2005 (gap)
• Feb 11, 2004
• May 20, 2005
• August 21, 2004
• August 24, 2005 (gap)
• October 12, 2002 (free)

True Color
Thermal Feb 2004 Jan 2005
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Landsat atmospheric correction

• Upwelling thermal emission includes atmospheric
  contribution and attenuation
• Requires local meteorology (e.g. NOAAs National
  Center Environmental Prediction) radiative
  transfer (MODTRAN)
• LTOA ????T Lu ? (1 - ?) Ld
• http//atmcor.gsfc.nasa.gov is a utility to
  determine ?, Lu and Ld for each acquisition
• Barsi (GSFC), Schott (RIT), Hook/Palluconi (JPL)
• Output is land surface temperature (T)
• Vicarious calibration campaigns suggest 1-2K
  accuracy

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Landsat Temperature Results
Date ? Lup Ldown Peak T
Feb 2004 0.91 0.55 0.94 26
May 2005 0.81 1.24 2.08 35
Aug 2004 0.75 2.04 3.32 42
Oct 2002 0.91 0.64 1.10 35
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ASTER instrument

• On EOS TERRA mission (launched 12/99)
• Joint US / Japan instrument (JPL)
• Zoom Lens of TERRA
• 15m Vis/NIR, 30m SWIR, 90m Thermal IR
• Total of 14 bands, 5 in the thermal infrared
• lt16 day repeat cycle
• 60km swath
• Sophisticated multi-band temperature and
  emissivity retrieval algorithms
• Extensive vicarious calibration campaigns

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ASTERs Spectral Bands
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ASTER coverage
lt100 coverage but 925,661 Scenes observed as of
9 Feb 2005
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ASTER Acquisitions of Lassen
Volcano Monitoring Project (http//www.volcano.si.
edu/gvp/volcano/index.htm)
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ASTER Image Log

• Archived data free to NASA researchers (W. Turner
  approval required, NASA HQ)
• 53 Acquisitions from May 2000 - May 2006
• 35 Day
• 15 Clear
• 18 Cloudy or Hazy
• 18 Night
• At least 9 Cloudy or Hazy
• Trying to obtain image concurrent w/ VFG mtg.

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Sample ASTER ImagesOctober 19, 2002
BSL Zoom Bands 321
BSL Zoom Temperature
Bands 321 False Color
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ASTER Day Temperatures(Removing 2 hazy dates)
Temperature
Date Within Year
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ASTER Day/Night Results
Temperature
Date Within Year
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Issues with ASTER Temperatures

• Spillover to ground?
• Point spread function is not rectangular
• Peak pixel does not measure just lake.
• Lower ground temperatures may be bringing down
  lake temperatures. Perhaps indicated in night
  data?
• Shadowing?
• Lower sun angle in winter could result in
  shadowing of hotter parts of the lake.
• Night data indicate this is not a major issue.
• Other unknown systematic effects?

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Aerial Thermal Remote Sensing

• QWIP detector developed at GSFC
• Quantum Well Infrared Photoconductor
• 1024 x 1024 GaAs array
• 4 bands in thermal IR (T and ? retrieval)
• Investigating aerial (or even hillside) data
  collection at BSL later this summer/fall
• Data collection in winter could validate the
  ASTER/Landsat temperature trends.

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Sample QWIP Image
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Multispectral Thermal Imager (MTI)

• DOE technology development mission
• Launched ca 2000
• Point and Shoot mission, 10 scenes/day
• 20m resolution thermal data (5?m and 10?m)
• Highest resolution thermal imaging from space
• Operated 2 years, now in storage on orbit
• No acquisitions of Lassen/BSL, but Yellowstone
  data do exist and I have some in hand.
• Perhaps of interest to others

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ASTER Imaging Opportunities

• ASTER needs to be tasked to take specific images
• I have requested an allocation with NASA HQ under
  the name of NAI ViFoG
• See me if ASTER data would be useful for any
  upcoming field campaigns.

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Backup
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