Field strength distributions of standard frequencies and time signal emissions in and near Japan

The field strength of the standard frequency and time signals JJY were measured at five locations in Japan. Median values of the JJY signals compared well with the average calculated signals. Field strength distributions of JJY, BPV (Shanghai) and WWVH (Hawaii) signals near Japan were calculated on computer. Theoretical results are derived for measuring the field strengths of emissions received near Japan, which are taken as basic data for studying the problem of mutual interference. The signals considered are the 5 MHz and 10 MHz signals of the stations JJY, BPV, and WWVH.