High Resolution MODIS Ocean Color Bryan Franz NASA Ocean Biology Processing Group MODIS Science Team Meeting, 4-6 January 2006, Baltimore, MD

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)

MODIS Land Bands BandWavelengthResolution

MODIS Land Bands BandWavelengthResolution * * band 5 failing on MODIS/Aqua

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)

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.

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.

HIRES MODIS BandWavelengthResolutionSNR(1km SNR) (802) (750) (910) (516) * * band 5 failing on MODIS/Aqua

RGB Image Standard MODIS vs HIRES MODIS 1-km 250-meter 75%

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

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).

1-km 250-meter Chlorophyll Standard MODIS vs HIRES MODIS 75%

1-km250-meter 70% 280%

1-km nLw(551)250m nLw(555) Full 5-minute Granule 28%7%

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 1KM+HKM+QKM = 900MB (5 minute granule)

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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