DIURNAL VARIATIONS IN THE NUMBER OF SHOWER METEORS DETECTED BY THE FORWARD-SCATTERING OF RADIO WAVES: PART I. THEORY

1955 ◽  
Vol 33 (9) ◽  
pp. 493-503 ◽  
Author(s):  
C. O. Hines
Keyword(s):  
Diurnal Variation ◽  
Incidence Rate ◽  
Forward Scattering ◽  
Diurnal Variations ◽  
Time Interval ◽  
Weight Factor ◽  
Radio Waves ◽  
Meteor Trails

Various observational factors affect the number of shower meteors which can be detected, in a given time interval, by the scattering of radio waves from the ionized meteor trails. The pertinent factors in the case of forward-scattering, where the transmitter and receiver are widely separated, are expressed approximately as functions of the position of the shower radiant. In combination, they provide an observational weight factor which may change appreciably as the radiant moves in the course of a day. The consequent diurnal variation in the occurrence of scattered signals may then be determined, and distinguished from variations due to random changes in the incidence rate of the meteors.

THE FORWARD-SCATTERING OF RADIO WAVES FROM OVERDENSE METEOR TRAILS

1957 ◽  
Vol 35 (9) ◽  
pp. 1033-1041 ◽  
Author(s):  
C. O. Hines ◽  
P. A. Forsyth
Keyword(s):  
Charge Density ◽  
Forward Scattering ◽  
Point Of View ◽  
Radio Waves ◽  
Geometric Factors ◽  
Meteor Trails

The forward-scattering of radio waves from overdense meteor trails is treated from an elementary point of view. The results indicate that the same geometric factors enter this problem as enter the problem of forward-scattering from underdense trails, and that the transition between underdense and overdense trails occurs at the same value of charge density as in the backscatter case. These conclusions are not expected to be generally valid when applied to individual trails, but at least they should provide a valid basis for the interpretation and prediction of the effects produced statistically by a large number of trails.

THE NUMBER DENSITY OF METEOR TRAILS OBSERVABLE BY THE FORWARD-SCATTERING OF RADIO WAVES

1956 ◽  
Vol 34 (10) ◽  
pp. 997-1004 ◽  
Author(s):  
Robert E. Pugh
Keyword(s):  
Forward Scattering ◽  
Radio Waves ◽  
Number Density ◽  
Meteor Trails

The number of meteor trails which can be detected by the forward-scattering of radio waves varies with the region of the sky under observation. The number density is determined theoretically, as a function of position relative to the transmitter and receiver.

A THEORETICAL RATE–AMPLITUDE RELATION IN METEORIC FORWARD-SCATTERING

1958 ◽  
Vol 36 (5) ◽  
pp. 539-554 ◽  
Author(s):  
C. O. Hines
Keyword(s):  
Observational Data ◽  
Forward Scattering ◽  
Occurrence Rate ◽  
Radio Waves ◽  
Scaling Factors ◽  
Meteor Trails ◽  
Amplitude Level ◽  
Good Agreement

The theory of the forward-scattering of radio waves by ionized meteor trails is applied to the development of a rate-amplitude relation. This relation expresses the anticipated occurrence rate of scattered signals which exceed a chosen amplitude level, as a function of that level. It is compared with preliminary observational data, and found to be in good agreement both qualitatively and quantitatively. Closest agreement is obtained only with an appropriate choice of two scaling factors. These provide an abstract of the observations in a form which is convenient for further study and interpretation.

FORWARD-SCATTERING OF RADIO WAVES BY METEOR TRAILS

1955 ◽  
Vol 33 (5) ◽  
pp. 176-188 ◽  
Author(s):  
P. A. Forsyth ◽  
E. L. Vogan
Keyword(s):  
Forward Scattering ◽  
Radio Waves ◽  
Preliminary Results ◽  
Meteor Trails ◽  
The Individual

Radio waves which are too high in frequency to be reflected by the ionospheric layers are often reflected back to the earth's surface by the ionization in meteor trails, and may be detected at distances of the order of 1000 kilometers from the transmitting station. These forward-scattered signals have been studied by the use of several transmission paths in Canada. The paper summarizes the characteristics of the individual signals and presents some preliminary results of the investigation. It seems likely that the technique will prove to be useful in meteoric studies.

HEIGHT-GAIN IN THE FORWARD-SCATTERING OF RADIO WAVES BY METEOR TRAILS

1957 ◽  
Vol 35 (1) ◽  
pp. 125-127 ◽  
Author(s):  
C. O. Hines ◽  
M. O'Grady
Keyword(s):  
Forward Scattering ◽  
Radio Waves ◽  
Height Gain ◽  
Meteor Trails

DIURNAL VARIATIONS IN THE NUMBER OF SHOWER METEORS DETECTED BY THE FORWARD-SCATTERING OF RADIO WAVES: PART II. EXPERIMENT

1955 ◽  
Vol 33 (10) ◽  
pp. 600-606 ◽  
Author(s):  
P. A. Forsyth ◽  
C. O. Hines ◽  
E. L. Vogan
Keyword(s):  
Specular Reflection ◽  
Forward Scattering ◽  
Diurnal Variations ◽  
Radio Waves ◽  
Forward Scatter ◽  
Transmission Path ◽  
Signal Rate ◽  
Cedar Rapids ◽  
Good Agreement

The theory developed in Part I is applied to derive the expected diurnal variations of the meteor signal rate for four showers as observed by means of a particular forward-scatter transmission path (Cedar Rapids – Ottawa). These results are then compared with the experimental signal rates. The good agreement obtained indicates that the approximations inherent in the theory are sufficiently accurate for practical purposes. The results also indicate that very few meteors, if any, are observed under conditions which do not satisfy the requirements for specular reflection.

DIURNAL VARIATIONS IN THE NUMBER OF SHOWER METEORS DETECTED BY THE FORWARD-SCATTERING OF RADIO WAVES: PART III. ELLIPSOIDAL THEORY

1958 ◽  
Vol 36 (1) ◽  
pp. 117-126 ◽  
Author(s):  
C. O. Hines
Keyword(s):  
Forward Scattering ◽  
Diurnal Variations ◽  
New Method ◽  
Radio Waves ◽  
Meteor Showers ◽  
Rigorous Results ◽  
Forward Scatter ◽  
Scatter Process ◽  
Full Development

A theory of meteor 'observability' relating to forward-scatter radio experiments was developed in Part I of this series, with the use of a simplifying 'cylindrical approximation'. The application of the theory to data obtained during meteor showers provides a promising new method for studying the intrinsic strengths of the showers. The principal limitation of the method is due to the inaccuracies of the cylindrical approximation. In the present paper, these inaccuracies are removed by a full development of the ellipsoidal geometry inherent in the forward-scatter process. The more rigorous results are compared with the approximate results at various stages throughout the analysis.

Analysis of meteor trails providing combined forward and backward scattering of radio waves

2021 ◽  
Vol 195 ◽  
pp. 105135
Author(s):  
I. Lapshina ◽  
S. Kalabanov ◽  
A. Karpov ◽  
A. Sulimov
Keyword(s):  
Radio Waves ◽  
Meteor Trails

3. On the Lunar Diurnal Variation of Magnetic Declination at Trevandrum, near the Magnetic Equator

1872 ◽  
Vol 7 ◽  
pp. 756-758
Author(s):  
J. A. Broun
Keyword(s):  
Diurnal Variation ◽  
Diurnal Variations ◽  
Magnetic Equator ◽  
Magnetic Declination ◽  
The Law ◽  
The Times

The author gives the results derived from different discussions of nearly eighty thousand observations, made hourly during the eleven years 1854 to 1864. They are as follows:—1. That the lunar diurnal variation consists of a double maximum and minimum in each month of the year.2. That in December and January the maxima occur near the times of the moon's upper and lower passages of the meridian; while in June and July they occur six hours later, the minima then occurring near the times of the two passages.3. The change of the law for December and January to that for June and July does not happen, as in the case of the solar diurnal variations, by leaps in the course of a month (those of March and October), but more or less gradually for the different maxima and minima.

scholarly journals Variation of diurnal Turbulence Kinetic Energy using sonic anemometer observation: a case study Ledeng, Bandung

2018 ◽  
Author(s):  
Sandy Hardian Susanto Herho ◽  
Dasapta Erwin Irawan
Keyword(s):  
Kinetic Energy ◽  
Diurnal Variation ◽  
Wind Velocity ◽  
Sonic Anemometer ◽  
Diurnal Variations ◽  
Turbulence Kinetic Energy ◽  
Atmospheric Conditions

Sonic anemometer observation was performed on 29 - 30 September 2014 in Ledeng, Bandung to see diurnal variations of Turbulence Kinetic Energy (TKE) that occurred in this area. The measured sonic anemometer was the wind velocity components u, v, and w. From the observation result, it can be seen that the diurnal variation that happened was quite significant. The maximum TKE occurs during the daytime when atmospheric conditions tend to be unstable. TKE values were small at night when atmospheric conditions are more stable than during the daytime.

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