The Aquarius Radiometer suite comprised three L-band microwave polarimetric radiometers to measure the brightness temperature of microwave emissions from the ocean surface with a center frequency of 1.413 GHz. The radiometers flew aboard the Aquarius/Satélite de Aplicaciones Científicas-D (Aquarius/SAC-D) platform, which was developed collaboratively between NASA and Argentina's space agency, the Comisión Nacional de Actividades Espaciales (CONAE), to best meet the goals of each agency while giving priority to salinity measurements. CONAE built complementary sensors to detect rain, sea ice, and wind speed, plus sea surface temperature sampling. CONAE-sponsored instruments — including those from the French Space Agency (Centre National d'Etudes Spatiales, CNES) and another from the Italian Space Agency (Agenzia Spaziale Italiana, ASI) — provide environmental data for a wide range of applications, including natural hazards, land processes, epidemiological studies, and air quality issues.