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We conducted meteor observations during the Leonid meteor shower on 16 November 2017 and 17 November 2018 with Langfang medium frequency (MF) radar (116° E, 40° N). This was the first nighttime meteor observation by MF radar in mid-latitude China. The observation period was 12:00–22:00 (UT) and the observation range was 78–150 km. By using broad ve...
Contexts in source publication
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... radar system consists of a transmitter, receiver, antennas and a data processing system. The spaced antenna array shown in Figure 1 consists of four orthogonal half-wave dipole antennas located at the vertices and center of an equilateral triangle with 181 m sides. The antennas are all used for transmission and reception. ...
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... bin was shifted by 1 hour or 1 km, and the calculation was repeated. Bi-hourly horizontal wind profiles during 16:00-22:00 UT on 16 November 2017 and 17 November 2018 are shown in Figures 9-12. The estimation errors were calculated in each plot (the calculation method can be referred to in Appendix A), and missing at some altitudes where wind estimation was given with only two meteor echoes. ...
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... averaged zonal and meridional winds from 12:00 to 22:00 UT were calculated with 4 km height bin and 1 km bin shifting. The estimation results are shown in Figures 13 and 14. Since an enlarged time bin contributes to dramatic increasing in meteor echo number, averaged horizontal winds from 96 km to 115 km were successfully obtained. ...
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... disagreements on some altitudes are evident in bi-hourly meridional wind profiles, although no wind reversal between them is found. In the comparison of whole night averaged zonal and meridional wind profiles shown in Figure 13, a consistent wind trend from 97 km to 110 km verifies our MF radar meteor wind estimation. Additionally, the upper height limit of the MF radar horizontal wind measurement was approximately 115 km, which is almost 10 km higher than VHF meteor radars. ...
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... meteor wind calculating under a condition of more than eight meteor echoes is more accurate and statistically significant [26]. As shown in Figure 13c, the meteor echo rate (in each time-height bin) detected by the MF radar from 97 km to 110 km is relatively high (no less than 9), which accounts for good agreement between the horizontal winds obtained by two radars at this attitude. On the other hand, the confidence of wind estimation by MF radar is not as good as that of VHF meteor radar below 100 km. ...
Citations
... This means that meteor radar echo detections could potentially routinely extend above 110 km [14]. Limited operation at MF has been achieved with difficulty without the improvements noted above [149][150][151] and would be greatly improved by applying them. Ref. [152] reports that a redeveloped approach to MF meteor winds has resulted in time resolutions as good as 10 min at Syowa Station (69° S, 39° E) in Antarctica, and these could be extended to the Saura lower HF radar in the Arctic referenced earlier. ...
This is an introductory review of modern meteor radar and its application to the measurement of the dynamical parameters of the Mesosphere Lower Thermosphere (MLT) Region within the altitude range of around 70 to 110 km, which is where most meteors are detected. We take a historical approach, following the development of meteor radar for studies of the MLT from the time of their development after the Second World War until the present. The application of the meteor radar technique is closely aligned with their ability to make contributions to Meteor Astronomy in that they can determine meteor radiants, and measure meteoroid velocities and orbits, and so these aspects are noted when required. Meteor radar capabilities now extend to measurements of temperature and density in the MLT region and show potential to be extended to ionospheric studies. New meteor radar networks are commencing operation, and this heralds a new area of investigation as the horizontal spatial variation of the upper-atmosphere wind over an extended area is becoming available for the first time.
... The radar has a pulse repetition rate of 80 Hz and a coherent accumulation of 32 at daytime, and a pulse repetition rate of 40 Hz and a coherent accumulation of 16 at night. A lot of data have been gathered with this radar [12,13], and we use radar data from July 2019 to June 2020. ...
In this paper, we investigate the activity of atmospheric turbulence in the MLT region and the relationship between the activity of atmospheric turbulence and atmospheric wave activity. We use data from the Langfang MF radar (39.4∘N, 116.7∘E) from July 2019 to June 2020 and NRLMSIS 2.0 to calculate the parameters of atmospheric wave activity and atmospheric turbulence energy dissipation rate (ε). Atmospheric ε is modulated by different periods at different altitudes, and while there are 12 h and 24 h periods at all altitudes, the main period is different at different altitudes. A comparison of the ε with atmospheric tide activity shows that tides have an effect on ε, and the influence of tides on ε may be different at different altitudes. The pattern of variation in ε is similar to that of the atmospheric activity of the gravity wave, with both ε and the atmospheric activity of the gravity wave showing significant semi-annual variation.
