Maximum observed frequency in HF backscatter ionogram and day variblelaw of slope distance.
高频返回散射电离图中最高观测频率、斜距的日变化规律;
The oblique sounding is one of the powerful tools, by which an oblique ionogram is obtained with the group path or time delay against operating frequency.
斜向探测是电离层探测的主要方式之一,它能够获得电波传播群时延和频率关系的电离图。
An oblique Ionogram is a plot showing the group path or time delay against operating frequency when using swept frequency obliquely sounding between the transmitting and receiving site.