The Millimetef-wave Imaging Radiometer (MIR) is a total-power passive microwave radiometer with channels at frequencies of 89, 150, 183.3+-1, 183.3+-3, 183.3+-7, 220, and 325 GHz, and it is used for measurements of atmospheric water vapor and precipitation (Racette et al. 1995). For cloud and precipitation regions, the channels on this instrument respond primarily to scattering from ice regions of clouds, with the lower free uencies penetrating progressively further into the cloud. The 183 GHz and lower-frequency channels on NIIR are currently flown on the SSMII and SSM/T2 spaceborne instruments. The MIR instrument is located in the right ERA wing superpod and scans S7 points cross-track +- 5Q? (each seen cycle takes about 2.9 s)Ail channels have a beamwidth of approximately 3.3? resulting in a spot size of about 0.5 km at a 10 km altitude typical of the ice scattering region in thunderstorms. The polarisation state of the measurements rotates with scan angle such that at nad ir, the elecinc field is perpendicular to the direction of flight. Additional information available at "http://lba.cptec.inpe.br/lba/eng/amc/er-2.htm"
MIR
Radiometers