The New Method of estimating ZHR using Radio Meteor Observations

Hirofumi Sugimoto (The Nippon Meteor Society) It has been very difficult to estimate Zenithal Hourly Rate in the case of Radio Meteor Observations, although it is very useful method for catching all meteor activities even if in bad weather or daytime. This research tries to estimate Zenithal Hourly Rate using Radio Meteor Observations. 1. Introduction As a known method for combining all radio meteor observations, H. Ogawa et al.(2001) published a new index that was “Activity Level” Index. Although this index is very useful for catching meteor activity profiles (period, level etc.), it is impossible to compare with visual observations. This research tried to estimate Zenithal Hourly Rate using radio meteor observations. By using this estimated ZHR, it becomes possible to discuss on the same table as visual observations. 2. Method An estimated ZHR is led by steps as following. (1) correcting machine feature such as antenna, receiver, receiving level, etc. and removing sporadic meteors (2) correcting limiting magnitude (3) correcting radian elevation (4) combining all calculated data 2.1. correction machine features This step adopts previous method by H. Ogawa et al.(2001). First step means as same as leading to Activity Level index. Activity level is led by as following formula. A(t) = [ N_obs(t) – N_ave(t) ] / D_ave where, N_obs is the hourly rate of observed meteor echoes. N_ave is the background level past two weeks. N_ave,...

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