Clouds and the Earth's Radiant Energy System (CERES)
There are two identical CERES instruments aboard Terra that measure the Earth's total radiation budget and provide cloud property estimates that enable scientists to assess clouds' roles in radiative fluxes from the surface to the top of the atmosphere. One CERES instrument operates in a cross-track scan mode and the other in a biaxial scan mode. The cross-track mode essentially continues the measurements of the Earth Radiation Budget Experiment (ERBE) and the Tropical Rainfall Measuring Mission (TRMM), while the biaxial scan mode provides new angular flux information that has improved the accuracy of angular models used to derive the Earth's radiation balance.
Two CERES sensors also fly aboard Terra's sister ship—Aqua.
CERES Web Site (Langley Research Center)