Optomechanical design of nine cameras for the Earth Observing Systems Multiangle Imaging Spectro-Radiometer, TERRA platform

The Multi-Angle Imaging Spectro-Radiometer is a push-broom instrument using nine cameras to collect data at nine different angles through the atmosphere. The science goals are to monitor global atmospheric particulates, cloud movements, and vegetative changes. The camera optomechanical requirements were: to operate within specification over a temperature range of 0C to 10C; to survive a temperature range of -40 degrees C to 80 degrees C; to survive launch loads and on-orbit radiation; to be non-contaminating both to itself and to other instruments; and to remain aligned through the mission. Each camera has its own lens, detector, and thermal control. The lenses are refractive; thus passive thermal focus compensation and maintaining lens positioning and centering were dominant issues. Because of the number of cameras, modularity was stressed in the design.