NOAA CoastWatch produces near real-time ocean color
products from the Moderate Resolution Imaging Spectroradiometer (MODIS)
on-board the NASA Earth Observing System (EOS) Terra and Aqua satellites.
The global Rate Buffered Data (raw satellite data or RBD) are obtained from
the NASA Goddard Space Flight Center (GSFC). NOAA processes the RBD to
Level 0 datasets, then to Level 1A radiances, and then to Level 1B
calibrated, geolocated radiances.
CoastWatch produces derived geophysical products (Level 2) from the
calibrated Level 1B radiances using the
NASA SeaDAS software. These products are then mapped (Level 3) to the
CoastWatch geographic regions.
Products generated by NOAA are of operational quality and will likely
differ from the same product generated by NASA.
Due to the constraint imposed on near-real time generation, NOAA uses
forecast ancillary data from the Global Forecast System (GFS) and predicted
ephemerides. These ancillary data are different than those
used in production of the NASA science products, but the resulting products
show good agreement with respect to patterns and gradients which are important
for operational applications. Additionally, although NOAA strives
to implement the most recent versions of the MODIS calibration tables and
software on its near-real time processing system,
it cannot always achieve this objective and may be running a different
version than that implemented on
NASA's science processing system.
Science quality MODIS ocean color products are available from NASA's
Ocean Biology Processing Group.
CoastWatch makes available chlorophyll products using both the standard
algorithm (OC3) and a regionally tuned algorithm for Chesapeake Bay
(Werdell, P. Jeremy, et. al., Approach for the long-term spatial and temporal
evaluation of ocean color satellite data products in a coastal environment,
Proc. Of SPIE Vol. 6680, 66800G, 2007).