How do AMSR and AMSR-E improve upon previous passive microwave radiometers?

First, the spatial resolution of AMSR/ADEOS-II and AMSR-E/Aqua data doubles the resolution of Scanning Multichannel Microwave Radiometer (SMMR) and Special Sensor Microwave/Imager (SSM/I) data.

Second, AMSR and AMSR-E each combine into one sensor all the channels that SMMR and SSM/I had individually. Both have the lower channels which were only on SMMR, as well as a higher frequency channel which was only on SSM/I. SMMR has the following channel frequencies: 6.6 GHz, 10.7 GHz, 18 GHz, 21 GHz, and 37 GHz. SSM/I has the following channel frequencies: 19.3 GHz, 22.3 GHz, 37 GHz, 85.5 GHz. In comparison, each of the AMSR instruments has the following frequencies: 6.9 GHz, 10.7 GHz, 18.7 GHz, 23.8 GHz, 36.5 GHz, and 89 GHz. See the Comparative Operating Characteristics of SMMR, SSM/I, and AMSR table on the AMSR-E Instrument Description Web page.