Presented at the 2015 Aquarius/SAC-D Science Team MeetingThe Central Florida Remote Sensing Lab (CFRSL), in collaboration with CONAE, have developed two improved algorithms to convert the radiometric counts to brightness temperature (Tb) for production of MWR level-1 science data. This poster presents a description of these algorithms and shows results for MWR Cal/Val activities during the past 15 months. Version 6.0 provides corrections to the previous MWR Tb algorithm (V5.0S) that remove a small nonlinearity in the radiometer transfer function. This algorithm is based upon: 1) a reanalysis of pre-launch thermal vacuum radiometric calibration testing to derive the antenna switch matrix loss coefficients, and 2) on orbit intersatellite cross calibrations (XCAL) with the Naval Research Labâs WindSat radiometer. Results are presented that demonstrate excellent radiometric stability for a 12 month data set over both oceans and land. Also a second version (V7.0) of MWR counts to Tb algorithm is presented. This algorithm is essentially V6.0 that has been normalized to WindSat as a radiometric transfer standard. By using the CFRSL XCAL double-difference technique, small radiometric biases between channels have been removed as well as systematic radiometric calibration drift over the entire MWR time series (~ 3 years). Comparisons between V6.0 and V7.0 are presented relative to WindSat.