A Clouds and the Earth's Radiant Energy System instrument (FM2) on board the Terra satellite
has been used in field campaigns to provide TOA radiance measurements. Using a special programmable
azimuth plan scan (PAPS) mode, a scanner collects data over a specified Earth target or of a prescribed
spatial orientation. This paper covers operational aspects of four field campaigns in which FM2 participated
in 2008. These include the annual CERES/GERB comparison campaign carried out at the summer and
winter solstices, an aerosol campaign over Beijing ran before, during and after Summer Olympics,
calibration and validation of GERB radiances at the ground station in Alacar/Spain, and also a bi-weekly
true long-track scan for comparison to true nadir instruments.