The advanced microwave radiometer (AMR) is a critical payload on the recently launched Jason-3 mission, designed to provide the electrical range delay of the radar altimeter signal due to tropospheric water vapor and cloud liquid water [1]. The errors in the wet tropospheric path delay measurements have a direct impact on the record of global mean sea level (GMSL) and could lead to uncertainty in derived trends if spurious drifts in the radiometer are not accounted for. Therefore, it is imperative to quantify and correct radiometer calibration drift, enabling producing of a high-quality stable record of wet tropospheric path delay for use in the development of GMSL.