Microwave Imaging Radiometer with Aperture Synthesis (MIRAS) is the major instrument on the Soil Moisture and Ocean Salinity satellite (SMOS).
MIRAS employs a planar antenna composed of a central body (the so-called hub) and three telescoping, deployable arms, in total 69 receivers on the Unit.
Each receiver is composed of one Lightweight Cost-Effective Front-end (LICEF) module, which detects radiation in the microwave L-band, both in horizontal and vertical polarizations.
The arrangement and orientation of MIRAS makes the instrument a 2-D interferometric radiometer that generates brightness temperature images, from which both geophysical variables are computed.
The MIRAS instrument's prime contractor was EADS CASA Espacio, manufacturing the payload of SMOS under ESA's contract.