FIGURE 1.1 Qualitative illustration of the contributions of water-leaving radiance Lw surface glint, and atmospheric path radiance to the measured TOA radiance.
SOURCE: Adapted from http://www.gps.gov/multimedia/images/.
FIGURE 1.2 Quantitative illustration of the contributions of water-leaving, surface-reflected, and atmospheric path radiance to the measured TOA radiance. The water-leaving radiance—the signal—is at most 10 percent of the TOA radiance (simulations by the HydroLight and Modtran radiative transfer models using typical oceanic and atmospheric properties and 10-nm wavelength resolution).
Climate Data Records (CDRs), it is essential to archive Level 0 data, pre-launch calibration and characterization information, and post-launch calibration and stability monitoring data to enable periodic reprocessing of the raw data. Note: CDRs have been defined as “time-series of measurements of sufficient length, consistency, and continuity to determine climate variability and change,” in the NRC report on CDRs from Environmental Satellites (NRC, 2004b).
Level 2: Level 2 data are generated from Level 1 data following atmospheric correction that are in the same satellite viewing coordinates as Level 1 data (i.e., the data have not been mapped to a standard map projection or placed on a grid). Level 2 data include Lw and derived products. Satellite viewing angles and other information are used to map any single Level 2 scene to a standard map projection (see definition of Level 3 data). Lw or ocean color radiance is generated from Level 1 radiance following atmospheric correction. Atmospheric correction for optically deep water3 requires sensor measurements at near and short wave infrared wavelengths, ancillary measurements such as sea-level atmo-
3 Optically deep water refers to water that is deep enough that the bottom reflectance does not contribute to the water-leaving radiance.