Location
University of Utah
Start Date
5-10-1999 1:30 PM
Description
The occurrence of short-lived sporadic E (Es) events at rates up to several per hour have been observed in ionograms recorded by the NOAA dynasonde operated at Utah State University's (USU) Bear Lake Observatory (41.9°N, 111.4°W). Because these Es events tend to occur predominantly between local midnight and early afternoon, have a wide radio bandwidth, and occur at ranges <150 km, a meteoric origin is assumed. While many Es events are very short-lived and detected only over a narrow frequency range, numerous events exhibiting wide radio bandwidths have been observed. Conventional meteor radar systems typically operate in the VHF range, although several studies have been conducted using HF radars, where the duration of the echoes is much longer. While direct reflections from individual meteor ionization trains are not uncommon in vertical incidence HF sounding, relatively few reports have appeared in the literature. In this paper, we utilize the full vector capabilities of the dynasonde to derive meteor echo amplitude, height distribution, temporal duration, and Doppler shift as a function of frequency from data collected during the Leonids shower of November 17 and 18, 1998.
A Study of Meteor Echoes at HF Using the Bear Lake Dynasonde
University of Utah
The occurrence of short-lived sporadic E (Es) events at rates up to several per hour have been observed in ionograms recorded by the NOAA dynasonde operated at Utah State University's (USU) Bear Lake Observatory (41.9°N, 111.4°W). Because these Es events tend to occur predominantly between local midnight and early afternoon, have a wide radio bandwidth, and occur at ranges <150 >km, a meteoric origin is assumed. While many Es events are very short-lived and detected only over a narrow frequency range, numerous events exhibiting wide radio bandwidths have been observed. Conventional meteor radar systems typically operate in the VHF range, although several studies have been conducted using HF radars, where the duration of the echoes is much longer. While direct reflections from individual meteor ionization trains are not uncommon in vertical incidence HF sounding, relatively few reports have appeared in the literature. In this paper, we utilize the full vector capabilities of the dynasonde to derive meteor echo amplitude, height distribution, temporal duration, and Doppler shift as a function of frequency from data collected during the Leonids shower of November 17 and 18, 1998.