Perseid meteor stream : cross and longitudinal structures from radar observations

Results of 23 years of observations of the Perseid meteor shower by the Ondřejov meteor radar in the period 1958–1996 are presented. Activity profiles in four categories of echo durations differ slightly in the position of the activity peak and other characteristics of the central core in the range of solar longitudes (Eq.1950.0) 138.0° ⩽ L○· ⩽ 140.5°. Maximum activity of the central core is allocated at L○· = 139.17°±0.06° in accordance with previous studies. The variation ratio of the year-to-year shower activity along the stream within the above L○· limits was found to be 2.2 : 1.