SeaWiFS Reprocessing #4 - Changes

Below are presented three groups of changes which have been considered since the last SeaWiFS reprocessing (May 2000). The first group includes changes that have either been accepted, or have been shown to produce sufficient benefit that they are very likely to be accepted with further testing and/or refinement. The changes in the second group are still under consideration, and have not yet been shown to produce benefits or lack adverse effects. The third group has already been thoroughly tested, and we believe have been shown to produce no appreciable benefit at this time. In addition, a number of analyses and access to imagery are presented as well.

• Accepted Changes:
  1. Calibration
     1. Changes to the Lunar Calibration Data Analysis
     2. Residual Time Drift Correction
     3. MOBY stray light correction
     4. Vicarious calibration modifications
        1. Inverse vicarious calibration procedure
        2. Gain Coefficients
  2. NIR Correction
     1. Chlorophyll-based NIR correction ramp-in
        1. Revised iteration control
     2. Update to IR absorption coefficients
     3. Revised backscatter model for NIR bandsRevised iteration control
  3. Atmospheric correction
     1. NIR relative noise reduction
     2. Improved handling of very clear atmospheric conditions
        1. Fixed aerosol model for very low or negative B7/B8 rho-a
        2. Ignore (Lt - Lr < 0):
     3. Out-of-band nLw correction
     4. F0 correction (pre- vs. post-out-of-band)
  4. Masks and Flags
     1. L3 Masking
     2. Revise the Turbid Water Flag
     3. High-Lt Masking
     4. Eliminate the Sun Glint Mask
     5. Stray Light Correction, Flagging and Masking
     6. Extend the Satellite Zenith Threshold
     7. Alternate Cloud Flagging Algorithm
     8. Revised Thresholds for Absorbing Aerosol Flag
     9. Shallow Water Mask Based on ETOPO2
  5. Navigation improvements
  6. Space binner OCTS updates
  7. Products
     1. Store chlorophyll product as floating point values
     2. PAR product
     3. New Suite of 4.6 kilometer Global Ocean Products
     4. Land products
• Items for Future Consideration:
  1. Calibration
     1. Revised At-launch Gains
     2. IR band alternative calibration schemes
        1. Absolute calibration of Band 8
        2. Fixed model
        3. AOT-based calibration
        4. AOT-based model selection
     3. Wind speed dependence for gain computation
  2. Masks and Flags
     1. Alternate cloud shadow algorithm
  3. Atmospheric Correction
     1. Revised Solar Irradiance Model
     2. Alternative aerosol model selection algorithm
     3. N02 correction
     4. Pressure dependence on the band 7 oxygen absorption correction
     5. f/Q correction
  4. Products
     1. Revert to At-Launch K490 Algorithm
     2. TAUA_865 Product Vicarious Calibration
     3. Log-Scaled Chlorophyll Product