The TCSP AMPR Brightness Temperature (TB) dataset consists of brightness temperature measurements from July 5, 2005 to July 27, 2005. The Advanced Microwave Precipitation Radiometer (AMPR) remotely senses passive microwave signatures of geophysical parameters from an airborne platform. The instrument is a low noise system which can provide multi-frequency microwave imagery with high spatial and temporal resolution. AMPR data are collected at a combination of frequencies (10.7, 19.35, 37.1, and 85.5 GHz) unique to current NASA aircraft instrumentation. These frequencies are well suited to the study of rain cloud systems, but are also useful to studies of various ocean and land surface processes. AMPR data were collected at four microwave frequencies (10.7, 19.35, 37.1 and 85.5 GHz).