Introduction.
=============

This directory structure contains the ESA Ocean Colour Climate Change Initiative
version 4.0 dataset release, consisting of uncertainty-characterised, level 3
mapped chlorophyll, remote sensing reflectance and inherent optical properties.

For more information, please:
 - read the quickstart and directory structure description below
 - download the Product User Guide (PUG) in the documentation directory
 - contact us at help@esa-oceancolour-cci.org


Quick start.
============

 - The geographic projection netCDFs will be most immediately usable in standard
   packages and programming libraries.  They are CF-convention compliant.

 - SNAP (http://step.esa.int/main/toolboxes/snap/) is a quick and well featured 
   tool for visualising and exploring the data.  Please see the User Guide (PUG) 
   in the documentation directory for examples of how to use the program.

 - Browse to the appropriate netCDF level and download data.
  - Alternative browse methods can be found on http://www.oceancolour.org/

 - if you have problems, please read the Product User Guide (PUG) in the
   documentation directory or contact us at:

         help@esa-oceancolour-cci.org


What algorithms were used?
==========================

These choices were based on the results of the round-robin evaluation of
algorithms.  See the PUG for more details.

Chlorophyll: a blended merger of multiple algorithms (OC3, OCI [OC4+CI], OC5)
             with the weighting determined by water class memberships
IOP:         QAA (with Zhang bb coefficients)
Kd490:       Lee variant (with Zhang bb coefficients)
Rrs:         Mixed - SeaDAS for VIIRS and SeaWiFS L2, Polymer for MERIS and
             MODIS L2, bandshifted to SeaWiFS, cleaned up and merged.
Water types and uncertainty: following Tim Moore's approach with custom classes.


Directory structure.
====================

The layout of the directory structure should be relatively understandable, but
the layers consist of:

-- a choice of geographic and sinusoidal projections
 +- in each, netcdf (for data) and PNG (for quicklooks / convenience)
  +- product type (all, chlor_a only, etc)
   +- temporal structure (daily, 8 day, monthly, etc)
    +- time (year)
     +- the data