Techniques for the study of TID's with multi‐station rapid‐run ionosondes

Individual daytime traveling ionospheric disturbances (TID's) in the F ‐layer are studied using three ionosondes mutually approximately 150 km apart in northern New Hampshire and Vermont. The ionosondes were operated continuously for long periods of time, making ionograms every two minutes. Methods of scanning the continuous data for TID's, and of analyzing them, are described. Iso‐height contours are emphasized as superior to iso‐ionic contours for analysis. It is found that the direction toward which a TID travels is essentially independent of height within the disturbance and that the directions of travel cluster about the south‐southeast. Other parameters are found to be height‐dependent and will be the subject of future papers.