Rb. Lee et al., THE CLOUDS AND THE EARTHS RADIANT ENERGY SYSTEM (CERES) SENSORS AND PREFLIGHT CALIBRATION PLANS, Journal of atmospheric and oceanic technology, 13(2), 1996, pp. 300-313
The Clouds and the Earth's Radiant Energy System (CERES) spacecraft se
nsors are designed to measure broadband earth-reflected solar shortwav
e (0.3-5 mu m) and earth-emitted longwave (5->100 mu m) radiances at t
he top of the atmosphere as part of the Mission to Planet Earth progra
m. The scanning thermistor bolometer sensors respond to radiances in t
he broadband shortwave (0.3-5 mu m) and total-wave (0.3->100 mu m) spe
ctral regions, as well as to radiances in the narrowband water vapor w
indow (8-12 mu m) region. The sensors are designed to operate for a mi
nimum of 5 years aboard the NASA Tropical Rainfall Measuring Mission a
nd Earth Observing System AM-1 spacecraft platforms that are scheduled
for launches in 1997 and 1998, respectively. The flight sensors and t
he in-flight calibration systems will be calibrated in a vacuum ground
facility using reference radiance sources, tied to the international
temperature scale of 1990. The calibrations will be used to derive sen
sor gains, offsets, spectral responses, and point spread functions wit
hin and outside of the field of view. The shortwave, total-wave, and w
indow ground calibration accuracy requirements (1 sigma) are +/-0.8, /-0.6, and +/-0.3 W m(-2) sr(-1), respectively, while the correspondin
g measurement precisions are +/-0.5% and +/-1.0% for the broadband lon
gwave and shortwave radiances, respectively. The CERES sensors, in-fli
ght calibration systems, and ground calibration instrumentation are de
scribed along with outlines of the preflight and in-flight calibration
approaches.