Measurements of wideband medium frequency atmospheric noise have been made over the past several years in the southwestern United States. In part 1 of a two-part paper the measurement and data transcription system and the statistical analysis software used to analyze the data are presented. Specific results given in part 1 include the temporal structure of the noise and the distribution and time variation of the measured average noise power. In part 2, representative first- and higher-order statistics and the impact of the data on bandwidth and system performance are described. Specifically, bit error rate simulations of a coherent receiver operating in either modeled or measured atmospheric noise are presented.