As a general rule, the in situ source used by the OBPG for vicarious calibration is the Marine Optical BuoY (MOBY). Wherever possible, this is true for this reprocessing. However, for several sensors, the direct use of MOBY did not adequately remove intermission biases. These include the VIIRS and OLCI sensors.
Reasons for this are likely due to limited MOBY match-ups as a result exclusion for glint contamination, narrow swath width (OLCI), shorter mission time span, and an apparent instability in MOBY-derived Lwn (deviations from the norm) in early 2017.
In an effort to address these challenges until such time as they can be resolved or mitgated, an approach was developed based on the ocean reflectance model (ORM) described in Werdell et al., (2008).
A chlorophyll climatology for the MOBY site was derived based on the SeaWiFS measured chloropyll values. This climatology was used to seed the chloropyll-based ORM to derived target remote sensing reflectance values.
