Ocean Color Quality Monitor (OC-QA) for NRT Satellite Products

  Last updated: Dec-21-2016


The Ocean Color Quality Assessment Monitor (OC-QA)

NRT-QA monitors in near real-time:

  • Multiple sensor NESDIS Legacy & Operational Level 3 (Mapped) Ocean Color products (chlorophyll_a, nLw, Kd490, KdPAR) from SeaWiFS, MODIS, MERIS, VIIRS
    • Daily composite for CoastWatch boxes
    • Multi-day composites of the above
    • Time-series of the bulk statistics
  • Some experimental products using the operational Chlorophyll Anomaly product averaged over many days
  • Histograms
  • Scatter plots
  • Relative Difference Maps
  • Stratified Time Series data (by Bathymetry and Chlorophyll values)

Major objectives of OC-QA:
  • Check various L2 and L3 Ocean Color products for self- and cross- consistency, and stability
  • Facilitate identifying product anomalies and possibly attributing their causes (e.g., sensor malfunction/degradation, Masks applied, or Chlorophyll algorithm deficiencies)


NRT-QA analyses presented here complement the global validation work "L2 - in situ" done at NASA/OBPG for MODIS/SeaWIFS algorithm and products, applied in NRT mode for CoastWatch regions of interest. For VIIRS algorithm development, validation and calibration please refer to the NOAA Ocean Color group's webpages (STAR Ocean Color). The CoastWatch/OceanWatch NRT Ocean color product validation is presented as links here.


Chlorophyll distribution functions are log-normally distributed and hence all statistics is calculated in log-normal space to estimate gaussian statisitical parameters.


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