High Resolution MODIS Ocean Color

1
High Resolution MODISOcean Color

• Bryan Franz
• NASA Ocean Biology Processing Group

MODIS Science Team Meeting, 4-6 January 2006,
Baltimore, MD
2
Concept

• The goal is to investigate the utility of the
  250 and 500-meter land bands for ocean color
  applications. (talk by Arnone, posters by Gould,
  Gao)

3
MODIS Land Bands
Band Wavelength Resolution 1 645 250 2 859
250 3 469 500 4 555 500
4
MODIS Land Bands
Band Wavelength Resolution 1 645 250 2 859
250 3 469 500 4 555 500 5 1240
500 6 1640 500 7 2130 500
band 5 failing on MODIS/Aqua
5
Concept

• The goal is to investigate the utility of the
  250 and 500-meter land bands for ocean color
  applications.
• A second goal is to investigate the use of the
  short-wave IR bands for use in atmospheric
  correction, especially for coastal applications.
  (paper by Wang Shi)

6
Concept

• The goal is to investigate the utility of the
  250 and 500-meter land bands for ocean color
  applications.
• A second goal is to investigate the use of the
  short-wave IR bands for use in atmospheric
  correction, especially for coastal applications.
• Develop these capabilities for regional analyses
  by SeaDAS users, not for global production.

7
Concept

• The goal is to investigate the utility of the
  250 and 500-meter land bands for ocean color
  applications.
• A second goal is to investigate the use of the
  short-wave IR bands for use in atmospheric
  correction, especially for coastal applications.
• Develop these capabilities for regional analyses
  by SeaDAS users, not for global production.
• The approach is to define a virtual sensor (HIRES
  MODIS) which includes all the 250 and 500-meter
  channels, as well as a sufficient set of 1km
  ocean channels to enable the operation of most
  standard ocean product algorithms.

8
HIRES MODIS
Band Wavelength Resolution SNR (1km
SNR) 8 412 1000 880 9 443 1000 838 3 469 500
243 (802) 4 555 500 228 (750) 1 645 250 128
(910) 15 748 1000 586 2 859 250 201 (516) 5 1
240 500 74 6 1640 500 275 7 2130 500 110
band 5 failing on MODIS/Aqua
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RGB ImageStandard MODISvsHIRES MODIS
75
1-km
250-meter
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Progress to Date

• Initial implementation of HIRES MODIS processing
  into MSL12
• replicating radiances and path geometries to
  250-meter pixels
• interpolating geolocation to 250-meter resolution
• developed polarization LUTs for the land bands
• obtained Rayleigh tables from M. Wang
• interpolating aerosol tables
• Initial vicarious calibration to MOBY
• obtained MOBY radiances for the land band
  spectral response functions from D. Clark.
• Testing and refinement of software and approach
  underway
• coordination with NRL/Stennis

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Ocean Color Processing Test

• Using fixed aerosol type, with aerosol
  concentration from 859-nm band at 250-meter
  resolution
• OC2 chlorophyll algorithm using 469 and 555-nm
  bands at 500-meter resolution (P. J. Werdell).

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Chlorophyll Standard MODISvsHIRES MODIS
75
250-meter
1-km
13
1-km
250-meter
70
280
14
Full 5-minute Granule
1-km nLw(551)
250m nLw(555)
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Practical Considerations

• The OBPG does not retain the land-band data
  within the ocean data processing and distribution
  system. The 250 and 500-meter data are removed
  from the Level-1A file during ingest.
• Full Level-1A or Level-1B files must be obtained
  from the GES DAAC or via Direct Broadcast. DAAC
  L1A holdings are limited.
• Each resolution is stored in a separate Level-1B
  file (1KM, HKM, QKM) . All three are required to
  run 250-meter processing.
• Given Level-0 (Direct Broadcast) or Level-1A, the
  SeaDAS software can produce the three L1B files
  using the latest LUT.
• The files are big. Memory requirements are high.
• Level-1B 1KMHKMQKM 900MB (5 minute granule)

16
Future Plans

• Improved implementation into MSL12
• interpolate all radiances and path geometry to
  250-meter
• maybe include other 1km bands (488, 869) ?
• flexibility to switch resolution (1000m, 500m,
  250m), utilizing aggregated radiance fields from
  Level-1B
• Investigate use of SWIR bands for atmospheric
  correction
• 1240 1640 (Terra)
• 1640 2130 (Terra Aqua)
• Develop capabilities for subscene extraction at
  Level-1A
• Enhance SeaDAS to support HIRES MODIS
• processing and display

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End