The combined cumulative distributions of meteor trails vs peak signal amplitudes and vs durations represent a more reliable indicator of the meteoroid stream activity and, consequently, of the mass index variation.
![meteoroid gemini meteoroid gemini](https://www.amsmeteors.org/wp-content/uploads/2017/09/fireball-700x400.jpg)
The trends of the mass distribution of particles for the quoted meteor complexes are discussed in terms of variation of the mass index s and of steady-state conditions for each meteor population.
![meteoroid gemini meteoroid gemini](https://i.ytimg.com/vi/SAuNg7lH6yI/maxresdefault.jpg)
echoes with duration T < 0.2s suggests that the missing mass of meteor particles observed so far by backscatter radars in the 1E-6 - 1E-4 g mass range, is present in the form of faint high-velocity meteors, which ablate above the echo ceiling of conventional radars. The unexpected high proportion of short-lived. Read moreįorward scatter (FS) continuous wave (CW) meteor radar observations carried out during 1992-95 over the long baseline Bologna-Lecce in Italy, enabled us to determine the mass distribution versus duration of particles in main meteoroid streams (Lyrids, eta Aquarids, delta Aquarids, Perseids, Orionids, Leonids, Geminids) and the sporadic background. Moreover, non-gravitational forces in connection with solar radiation pressure, Poynting-RobertsonĮffect, solar-wind particle streaming, mutual collisions, etc., appear to be responsible for the observed widespread radiantsĪnd for unstable populations in the meteoroid streams. This is a possible consequence of longer-lasting FS signals, indicating a shift of the mass distribution functionvs. The values of the mass index of the sporadic complex are generally higher (2.07≤s≤ 2.57) than the corresponding ones of meteor showers in the range of echo durations 0.1≤T≤10 s. It was found that the mass indexs generally increases towards long-duration echoes, but many of the observed meteor streams appear to have unstable populations. Meteoroid streams was derived, and the values of the mass indexs were compared for each meteor population with the steady-state condition (s<11/6). duration of echoes belonging to main meteor showers (Lyrids, ν-Aquarids, δ-Aquarids, Perseids, Orionids, Leonids, Geminids)Īnd sporadic background were investigated using a forward-scatter (FS) continuous-wave (CW) meteor radar link operationalĭuring 1992–95 over the long baseline Bologna-Lecce in Italy. The cumulative distributions of the numbervs. A comparison with the records of 1986 Geminids at the Budrio backscatter radar station near Bologna, shows an asymmetric curve of activity, with smaller particles shifted to shorter and less eccentric orbits, the peak flux occurring earlier than that of larger ones. Both sets of data relative to the peak activity in December 12-14, show reflection properties of Geminids which are atypical if compared with echoes from cometary-type showers, with really high echo counts at mid-upper levels of the peak received power.
![meteoroid gemini meteoroid gemini](https://i.ytimg.com/vi/IvN3XdYfqMU/maxresdefault.jpg)
The observational results of the Geminid display obtained in the two consecutive years with differentiated peak levels of transmitted power, exhibit different time distributions of underdense meteors against the signal received power. Continuous radio-wave monitoring of the Geminid activity in December 19 by using a forward-scatter (FS) bistatic radar over the Bologna-Lecce baseline (700 km) in Italy, reveals peculiar structural aspects of the stream in terms of signal amplitude-rate and duration-rate dependence.