Radiometer antenna architecture for oceanography applications

Antennas for microwave remote sensing instruments require large apertures for sensitivity, depending on requirements. (Phased) Array antennas and large reflectors are used, both for active or passive instruments. Recently the 7th ESA Explorer mission Biomass was selected. It will use a deployable
parabolic reflector to be embarked on a not so big spacecraft for Low Earth Orbit (LEO) exploiting a feed-array. Also new architectures for radiometers are investigated. Antenna architectures will appear, using focal arrays combined with a large reflector. Such approach is already followed for terrestrial radio-astronomy in preparation for future Square Kilometre Array (SKA). Advances in integrated circuitry, both for RF frontends and processing circuitry, permit a needed lower power consumption, allowing eventually space applications. It is expected that multiple-beam multi-frequency radiometer instruments for space will appear and use such technology developments. The paper provides a short overview of past activities – even radio-astronomy - and gives recent information from an ESA study
on radiometry developments, addressing the shaped toroidal reflector antenna with focal plane array.