The Advanced Microwave Precipitation Radiometer (AMPR) was deployed during the First ISCCP Regional Experiment-III Arctic Cloud Experiment (FIRE-III/ACE). AMPR data were collected at four microwave frequencies (10.7, 19.35, 37.1 and 85.5 GHz) for the time period of May 18, 1998 through June 6, 1998. The FIRE-III/ACE mission studied sea-ice melting, sea-ice drift, and other sea-ice properties. The experiment was focused on the Arctic Ocean in and near the Beaufort Sea off the northern coast of Alaska, in coordination with the ice-bound research ship, Sheba.