Cloud Contamination in Landsat Imagery Current and Future

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					Cloud Contamination in Landsat Imagery:
      Cloud-Clearing with LTAP-8


           Samuel N. Goward, UMD
        Darrel L. Williams, NASA/GSFC
            Andrew Macatee, UMD
                   Members:
       USGS/NASA Landsat Science Team
Global Land Remote Sensing in Landsat 7 Era
       Year 2000 L7 “low-cloud” Coverage – USGS EROS
       Map Quality Imagery
      from Remote Sensing
• Land Surface Conditions

  –Orthorectified (DEMs)

  –Surface Reflectance (Atmosphere)

  –Cloud and Shadow-Free
Cloud Contamination Problem
L7 16-Day Temporal Repeat – Washington DC region, 2000
May 11                 May 27                June 12




 June 28               July 14              July 30
     Cloud Contamination
(L7 16-Day Temporal Repeat – Oregon region, 2000)
     May 19         June 04            June 20




    July 06           July 22          Aug 07
ACCA
16%
02JUN02
ACCA
5%
10JUN02
ACCA
13%
18JUN02
ACCA
10%
26JUN02
ACCA
2%
04JUL02
ACCA
0%
12JUL02
ACCA
71%
20JUL02
ACCA
10%
28JUL02
ACCA
19%
05AUG02
ACCA
0%
13AUG02
ACCA
55%
21AUG02
ACCA
90%
29AUG02
ACCA
0%
06SEP02
ACCA
80%
14SEP02
ACCA
54%
22SEP02
ACCA
10%
30SEP02
                 Smallsat Constellations? GEOSS?
           Conceptual Ground Imaging tracks from a Constellation of 4 Polar and
                                1 Equatorial Satellites.




Hansen, M, T. Loveland, et al, A Constellation of Mixed-Orbit Micro-Satellites for Monitoring Global Land
                       Change and Ecosystem Dynamics, SDSU& USGS EROS
June 2002
July 2002
August 2002




   No
  Data
September 2002
      Cloud/Shadow Clearing
      through Scene Merging
• GOAL
   – Combine 2 or more scenes to produce a merged
     clear land observations (not image compositing).
• APPROACH
   – atmospheric adjustment
   – cloud/shadow identification
   – land/water mask
   – “stable” land surface conditions
• QUALITY ASSURANCE
   – Scatter plot evaluation
June 2nd (red) June 18th (blue)
June 28th (blue) August 13th (red)
July 4th (red) August 5th (blue)

				
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