scholarly journals Tracking Meteor Trails to Study the Mesosphere

Eos ◽  
2017 ◽  
Author(s):  
Emily Underwood
Keyword(s):  
Radar Data ◽  
Upper Atmosphere ◽  
Meteor Trails ◽  
New Phenomena

Twelve years of radar data reveal new phenomena in Earth’s upper atmosphere.

THE DISTRIBUTION OF IONIZATION ALONG UNDERDENSE METEOR TRAILS

1964 ◽  
Vol 42 (11) ◽  
pp. 2035-2047 ◽  
Author(s):  
D. W. Rice ◽  
P. A. Forsyth
Keyword(s):  
Upper Atmosphere ◽  
Sources Of Error ◽  
Signal Characteristics ◽  
Radio Signals ◽  
Meteor Trails

Attempts to use the decay of radio signals reflected from individual meteor trails to study the upper atmosphere have revealed a puzzling inconsistency in the signal behavior. An earlier paper pointed out that this inconsistency remained even when the previously postulated sources of error were eliminated. As a result, an irregularly ionized trail model was proposed and shown, by calculation of signal characteristics, to be capable of accounting for the observations. This paper presents results of a new experiment which permitted the determination of the ionization profiles as the meteor trails were formed. The predicted irregularities were found, even for trails which exhibited apparently "ideal" underdense signal characteristics.

scholarly journals Monitoring observations of meteor echo at the EKB ISTP SB RAS radar: algorithms, validation, statistics

2021 ◽  
Vol 7 (1) ◽  
pp. 47-58
Author(s):  
Roman Fedorov ◽  
Oleg Berngardt
Keyword(s):  
Least Squares Method ◽  
Weighted Least Squares ◽  
Three Dimensional ◽  
Radar Data ◽  
Meteor Shower ◽  
Horizontal Wind ◽  
Doppler Velocity ◽  
Wind Model ◽  
Weighted Least Squares Method ◽  
Meteor Trails

The paper considers the implementation of algorithms for automatic search for signals scattered by meteor trails according to EKB ISTP SB RAS radar data. In general, the algorithm is similar to the algorithms adopted in specialized meteor systems. The algorithm is divided into two stages: detecting a meteor echo and determining its parameters. We show that on the day of the maximum Geminid shower, December 13, 2016, the scattered signals detected by the algorithm are foreshortening and correspond to scattering by irregularities extended in the direction of the meteor shower radiant. This confirms that the source of the signals detected by the algorithm is meteor trails. We implement an additional program for indirect trail height determination. It uses a decay time of echo and the NRLMSIS-00 atmosphere model to estimate the trail height. The dataset from 2017 to 2019 is used for further testing of the algorithm. We demonstrate a correlation in calculated Doppler velocity between the new algorithm and FitACF. We present a solution of the inverse problem of reconstructing the neutral wind velocity vector from the data obtained by the weighted least squares method. We compare calculated speeds and directions of horizontal neutral winds, obtained in the three-dimensional wind model, and the HWM-14 horizontal wind model. The algorithm allows real-time scattered signal processing and has been put into continuous operation at the EKB ISTP SB RAS radar.

scholarly journals Meteor velocity determination with plasma physics

2004 ◽  
Vol 4 (1) ◽  
pp. 1247-1268 ◽  
Author(s):  
L. P. Dyrud ◽  
K. Denney ◽  
S. Close ◽  
M. Oppenheim ◽  
L. Ray ◽  
...  
Keyword(s):  
Plasma Physics ◽  
Radar Data ◽  
New Method ◽  
Altitude Range ◽  
Meteor Trail ◽  
Radar Reflection ◽  
Head Echo ◽  
Meteor Trails ◽  
Plasma Reflection ◽  
Field Aligned Irregularities

Abstract. Understanding the global meteor flux at Earth requires the measurement of meteor velocities. While several radar methods exist for measuring meteor velocity, they may be biased by plasma reflection mechanisms. This paper presents a new method for deriving meteoroid velocity from the altitudinal extent of non-specular trails. This method employs our recent discoveries on meteor trail plasma instability. Dyrud et al. (2002) demonstrated that meteor trails are unstable over a limited altitude range, and that the precise altitudes of instability are dependent on the meteoroid velocity that generated the trail. Since meteor trail instability results in field aligned irregularities (FAI) that allow for radar reflection, non-specular trail observations may be used to derive velocity. We use ALTAIR radar data of combined head echos and non-specular trails to test non-specular trail derived velocity against head echo velocities. Meteor velocities derived from non-specular trail altitudinal width match to within 5 km/s when compared with head echo range rates from the same meteor. We apply this technique to Piura radar observations of hundreds of non-specular trails to produce histograms of occurrence of meteor velocity based solely on this non-specular trails width criterion. The results from this study show that the most probable velocity of meteors seen by the Piura radar is near 50 km/s which is comparable with modern head echo studies.

scholarly journals Diffusion Coefficients from the Rate of Decay of Meteor Trails

1955 ◽  
Vol 8 (2) ◽  
pp. 279 ◽  
Author(s):  
AA Weiss
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Effective Diffusion Coefficient ◽  
Effective Diffusion ◽  
Upper Atmosphere ◽  
Absolute Value ◽  
Meteor Trail ◽  
Rate Of Decay ◽  
Meteor Trails ◽  
Rates Of Decay

The effective diffusion coefficient for a meteor trail is calculated from the theory of ambipolar diffusion and the physical constants of the upper atmosphere. The absolute value of the diffusion coefficient so calculated, and also its gradient with height, are confirmed by measurement of the rates of decay of a large number of meteor echoes of known heights.

scholarly journals Approximations for the Electron Density in Meteor Trails

1958 ◽  
Vol 11 (4) ◽  
pp. 591 ◽  
Author(s):  
AA Weiss
Keyword(s):  
Exact Solution ◽  
Electron Density ◽  
Unit Length ◽  
Upper Atmosphere ◽  
Meteor Trails ◽  
Isothermal Atmosphere ◽  
Special Case ◽  
Meteor Particle

Herlofsen (1947) has shown that an exact solution of the equations governing the evaporation of a meteor particle during its flight in the upper atmosphere can be obtained in the special case of a spherical meteor in an isothermal atmosphere. In terms of the number n of meteor atoms evaporated in unit length of trail, the electron density a is . (1)

scholarly journals Meteor velocity determination with plasma physics

2004 ◽  
Vol 4 (3) ◽  
pp. 817-824 ◽  
Author(s):  
L. P. Dyrud ◽  
K. Denney ◽  
S. Close ◽  
M. Oppenheim ◽  
J. Chau ◽  
...  
Keyword(s):  
Plasma Physics ◽  
Radar Data ◽  
New Method ◽  
Altitude Range ◽  
Meteor Trail ◽  
Radar Reflection ◽  
Head Echo ◽  
Meteor Trails ◽  
Plasma Reflection ◽  
Field Aligned Irregularities

Abstract. Understanding the global meteor flux at Earth requires the measurement of meteor velocities. While several radar methods exist for measuring meteor velocity, they may be biased by plasma reflection mechanisms. This paper presents a new method for deriving meteoroid velocity from the altitudinal extent of non-specular trails. This method employs our recent discoveries on meteor trail plasma instability. Dyrud et al. (2002) demonstrated that meteor trails are unstable over a limited altitude range, and that the precise altitudes of instability are dependent on the meteoroid that generated the trail. Since meteor trail instability results in field aligned irregularities (FAI) that allow for radar reflection, non-specular trail observations may be used to derive velocity. We use ALTAIR radar data of combined head echos and non-specular trails to test non-specular trail derived velocity against head echo velocities. Meteor velocities derived from non-specular trail altitudinal width match to within 5 km/s when compared with head echo range rates from the same meteor. We apply this technique to Piura radar observations of hundreds of non-specular trails to produce histograms of occurrence of meteor velocity based solely on this non-specular trails width criterion. The results from this study show that the most probable velocity of meteors seen by the Piura radar is near 50 km/s, which is comparable with modern head echo studies.

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