Fig. 4From: Comparison of shipborne GNSS-derived precipitable water vapor with radiosonde in the western North Pacific and in the seas adjacent to JapanFrequency distribution of the 1 s ZTD variation obtained from the shipborne GNSS observations. The lines indicate the frequency of each bin divided by a 0.1-mm interval (left axis). The lines with points indicate the accumulated frequency (right axis)Back to article page