CZCS Reprocessing 2010.0

1. Introduction

The CZCS mission was reprocessed in July 2011, with the primary goal of bringing the processing algorithms and data formats into consistency with the R2010.0 reprocessings of SeaWiFS, MODIS, and OCTS. The CZCS instrument calibration and the general approach to the atmospheric correction are unchanged from the R2006 reprocessing.

2. Changes

The file format and content of the CZCS products were updated to be consistent with other sensors, e.g., SeaWiFS, including the change from normalized water-leaving radiances to remote sensing reflectances as the fundamental radiometric quantity reported. The atmospheric correction was updated to utilize the new aerosol model suite developed for the R2010.0 multi-sensor reprocessing (Ahmad et al., 2010). The CZCS atmospheric correction employed in R2006 relies on an assumed aerosol model, previously specified as the M90 (Maritime at 90% relative humidity) model of Gordon and Wang, 1994. For the R2010.0 reprocessing of CZCS, the atmospheric correction assumes r70f10 (10% fine mode fraction at 70% relative humidity) model of Ahmad et al., 2010. The CZCS atmospheric correction also requires an iterative modeling scheme to estimate the water-leaving radiance at 670nm. This model was updated to be consistent with Bailey et al., 2010, which describes the model employed to estimate the water-leaving radiance contribution in the near infrared channels of SeaWiFS, MODIS, and OCTS. Finally, the vicarious calibration of CZCS was updated based on the same Werdell et al., 2007 ocean surface reflectance model employed in R2006, but accounting for the R2010.0 changes to the atmospheric correction algorithm.