ABSTRACT
Landsat, microwave sounding units, Advanced Very High Resolution Radiometer, and others were designed and launched as operational weather-monitoring satellites, yet, their continued maintenance and longevity in orbit have provided for the creation of several very important long-running climate data sets. Data collected by Terra and the many climate research satellites that preceded it, have forever changed the field of climate science. The satellites, many of which are in commission, are closely spaced, ensuring that their collective observations, when combined, help construct a complete, three-dimensional understanding of the Earth system. In addition to the Landsat and Defense Meteorological Satellite Program satellites launched in the 1970s, the United States National Oceanic and Atmospheric Administration launched a series of polar-orbiting satellites—beginning in 1979—which were equipped with microwave sounding units used to derive the temperature of the troposphere via passive microwave measurements.
