What does “reprocessing” mean? Is reprocessed data better than the data I obtained in October?
When the data comes from the satellite, it’s just digital data — strings of numbers. The data has to be processed to derive meaningful remote sensing data. The first step in SeaWiFS data processing is to produce “raw” radiance data, the intensity of light for each band detected at the satellite. When navigation information is added, this becomes Level 1A data. Algorithms are then used to remove the effect of atmospheric light scattering and to account for the angle of the sun, producing normalized water-leaving radiances. This data can be combined in algorithms to produce other parameters, such as chlorophyll concentration. This level of processing is called Level 2 data. Level 3 data means that the data has been combined statistically into “bins” which contain all the data from a certain region collected daily, weekly, monthly, or annually. The SeaWiFS bins are square areas 9×9 kilometers in dimension. “Reprocessing” means that the SeaWiFS data has been processed again, using new and
