Abstract
The Radiation Budget Instrument (RBI) will continue the record obtained by the Clouds and the Earth’s Radiant Energy System (CERES) instruments of the total outgoing radiation emitted and reflected by the Earth. To obtain this record, RBI will view the Earth in three bands, a total band covering 0.2 to 100 microns, a short band from 0.2 to 5 microns and a long band from 5 to 100 microns. Data will be collected mainly in a whiskbroom mode at a sample rate of 100 Hz and 1.6x2.6 degree field of view from low Earth orbit. RBI is being built by Harris Inc. and RBI ground calibration will be performed by Space Dynamics Lab. In addition to the broad bandpass and large field of view, RBI has strict calibration requirements, such as 0.5% or better absolute accuracy in the total band and total band repeatability over one month better than 0.067 W/m^2-sr plus 0.033% of the signal. This presentation will focus on the SDL ground calibration of the RBI non-linearity, which needs to be measured to 0.05% of the maximum signal in each band. The method to obtain the non-linearity calibration with high accuracy and the estimated uncertainties will be discussed.
RBI Ground Calibration and Uncertainties Non-Linearity
The Radiation Budget Instrument (RBI) will continue the record obtained by the Clouds and the Earth’s Radiant Energy System (CERES) instruments of the total outgoing radiation emitted and reflected by the Earth. To obtain this record, RBI will view the Earth in three bands, a total band covering 0.2 to 100 microns, a short band from 0.2 to 5 microns and a long band from 5 to 100 microns. Data will be collected mainly in a whiskbroom mode at a sample rate of 100 Hz and 1.6x2.6 degree field of view from low Earth orbit. RBI is being built by Harris Inc. and RBI ground calibration will be performed by Space Dynamics Lab. In addition to the broad bandpass and large field of view, RBI has strict calibration requirements, such as 0.5% or better absolute accuracy in the total band and total band repeatability over one month better than 0.067 W/m^2-sr plus 0.033% of the signal. This presentation will focus on the SDL ground calibration of the RBI non-linearity, which needs to be measured to 0.05% of the maximum signal in each band. The method to obtain the non-linearity calibration with high accuracy and the estimated uncertainties will be discussed.