{"title":"Comparative study of the correlation of seasonal and diurnal cycles of transhorizon radio transmission loss and surface refractivity","authors":"B. Bean, L. Fehlhaber, J. Grosskopf","doi":"10.6028/JRES.066D.058","DOIUrl":"https://doi.org/10.6028/JRES.066D.058","url":null,"abstract":"","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"1024 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123326875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The propagation characteristics of uniform, cylindrical plasma columns of circular cross section, in constant axial magnetic fields are determined. The ratios (plasma wave-length)/(free-space wavelength) and (power flowing in the plasma)/(power flowing outside) are evaluated and discussed as functions of the diameter/wavelength ratio and of the plasma permittivity, for propagation of circularly syrnmetracl modes. Brillouin diagrams are also derived and compared with the results predicted by the quasi-static approximation. The analysis is carried out for a nonattenuating plasma, but formulas giving the attenuation caused by electron-molecule collisions are also included. (auth)
{"title":"Propagation Characteristics Of Magneto-Ionic Plasma Columns","authors":"D. Formato, A. Gilardini","doi":"10.6028/JRES.066D.053","DOIUrl":"https://doi.org/10.6028/JRES.066D.053","url":null,"abstract":"The propagation characteristics of uniform, cylindrical plasma columns of circular cross section, in constant axial magnetic fields are determined. The ratios (plasma wave-length)/(free-space wavelength) and (power flowing in the plasma)/(power flowing outside) are evaluated and discussed as functions of the diameter/wavelength ratio and of the plasma permittivity, for propagation of circularly syrnmetracl modes. Brillouin diagrams are also derived and compared with the results predicted by the quasi-static approximation. The analysis is carried out for a nonattenuating plasma, but formulas giving the attenuation caused by electron-molecule collisions are also included. (auth)","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"229 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116303226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Possible influence of the ionosphere on the impedance of a ground-based antenna","authors":"James R. Wait","doi":"10.6028/JRES.066D.055","DOIUrl":"https://doi.org/10.6028/JRES.066D.055","url":null,"abstract":"","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"2026 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129772997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
New observat ions h ave been made of the absolute intensity of in co herent seaLLe l' ec hoes from t he ionosphere, at a station ncar Lima, Peru . In order to analyze Lhese obse rvat ions properly, the paper begins wi t h a rederi vation of the radar equation in iLs form a ppropriate to in co herent scatter studies . The resul t of t hi s deri vation is tha t a correction factor of a pproximately 2 mu st bc appli ed to th radar equation in its form genera lly used in th is work. D etails given of t he observat ional parameters of the r adar sy. te m permit p rec ise compa riso n of t he present results with results of other worker. The observations indicate that t he average rad ar cross section per Fee electron is usua ll y c l o~e to the t heorctica ll y predicted valu e of one ha lf t he clas ical Thomson cross sec Lion. Thi s suggests that Lhe ionosphere is usua lly in a conditioll of thermal equilibrium beLween ion a nd e lectron s. Occasion ally , pa r t icula rl y a t sunrise, the observed cross section is s tilll o'er , approximatin g one quarter of t he classical Thomson cross section. Thi observation wou ld agree with Lhe theo retica l p red ic t ions of J . A. F eje r [19611 if the electron te mperature at sunri e in t he F r egion exceeds Lhe ion temperature.
在秘鲁利马的一个观测站，对来自电离层的非相干辐射的绝对强度进行了新的观测。为了正确地分析这些噪声，本文首先重新推导了适用于相干散射研究的红外雷达方程。这一推导的结果是，必须将一个近似于2 μ的修正因子应用于本工作中通常使用的雷达方程。给出了雷达系统观测参数的详细情况。他们允许将目前的结果与其他工人的结果进行比较。观察结果表明,t他每费用平均rad ar截面电子通常会y c l o ~ e e t heorctica ll y的预测价值的1公顷低频t他一堂课ical汤森十字交会狮子。这表明电离层通常处于离子a和电子s之间的热平衡状态。有时，在太阳升起时，当太阳升起时，观测到的横截面仍为1 / 2，约为经典汤姆逊横截面的1 / 4。这一观察结果与李氏的理论一致。A. F . e. r[19611]如果电子在太阳下的温度在F区超过离子温度。
{"title":"On the absolute intensity of incoherent scatter echoes from the ionosphere","authors":"K. Bowles, G. Ochs, J. Green","doi":"10.6028/JRES.066D.041","DOIUrl":"https://doi.org/10.6028/JRES.066D.041","url":null,"abstract":"New observat ions h ave been made of the absolute intensity of in co herent seaLLe l' ec hoes from t he ionosphere, at a station ncar Lima, Peru . In order to analyze Lhese obse rvat ions properly, the paper begins wi t h a rederi vation of the radar equation in iLs form a ppropriate to in co herent scatter studies . The resul t of t hi s deri vation is tha t a correction factor of a pproximately 2 mu st bc appli ed to th radar equation in its form genera lly used in th is work. D etails given of t he observat ional parameters of the r adar sy. te m permit p rec ise compa riso n of t he present results with results of other worker. The observations indicate that t he average rad ar cross section per Fee electron is usua ll y c l o~e to the t heorctica ll y predicted valu e of one ha lf t he clas ical Thomson cross sec Lion. Thi s suggests that Lhe ionosphere is usua lly in a conditioll of thermal equilibrium beLween ion a nd e lectron s. Occasion ally , pa r t icula rl y a t sunrise, the observed cross section is s tilll o'er , approximatin g one quarter of t he classical Thomson cross section. Thi observation wou ld agree with Lhe theo retica l p red ic t ions of J . A. F eje r [19611 if the electron te mperature at sunri e in t he F r egion exceeds Lhe ion temperature.","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130250284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thcrc is a curren t in terest in t he use of loops for t ran smitting and receiving clectromagnetic energy in a diss ipa t ive medium. Expressions for th e impedance of a loop in such a m edium are of valu e in des igning radiating and rccciving sys tems. Thc resistancc of a circular loop in a conducting medium has been discussed by Moore [1951] . In t he presen t papcr , expressions are derived fo r both the resis tance and reactance of a circular loop of thinly insulated wire which carries a uniform current a nd is surrounded by an infinite, homogeneous, condu cting medium. These express ions are valid if the wavelength in t he conducting medium is lal·ge compared with the diameter of the loop and if the displacernen t current in the m edium is negligible. Th e result for the resistan ce is compared with tha t of Wait [1957] for a circular loop in a spherical in sula ting cavity .
{"title":"Impedance of a circular loop in an infinite conducting medium","authors":"M. Kraichman","doi":"10.6028/JRES.066D.050","DOIUrl":"https://doi.org/10.6028/JRES.066D.050","url":null,"abstract":"Thcrc is a curren t in terest in t he use of loops for t ran smitting and receiving clectromagnetic energy in a diss ipa t ive medium. Expressions for th e impedance of a loop in such a m edium are of valu e in des igning radiating and rccciving sys tems. Thc resistancc of a circular loop in a conducting medium has been discussed by Moore [1951] . In t he presen t papcr , expressions are derived fo r both the resis tance and reactance of a circular loop of thinly insulated wire which carries a uniform current a nd is surrounded by an infinite, homogeneous, condu cting medium. These express ions are valid if the wavelength in t he conducting medium is lal·ge compared with the diameter of the loop and if the displacernen t current in the m edium is negligible. Th e result for the resistan ce is compared with tha t of Wait [1957] for a circular loop in a spherical in sula ting cavity .","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126899706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An analysis of VLF mode propagation for a variable ionospheric height","authors":"J. Wait","doi":"10.6028/JRES.066D.045","DOIUrl":"https://doi.org/10.6028/JRES.066D.045","url":null,"abstract":"","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131961419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The interaction between an obliquely incident plane electromagnetic wave and an electron beam ls studied theoretically. A static magnetic field of arbitrary strength is assumed to be present in the axial direction. Machine computations made for the case of a cylindrical electron plasma show that resonances occur in the backscattering cross section as a function of the angle of incidence of the plane wave. The dependence of the resonance angles on the plasma frequency for fixed gyrofrequency suggests a possibility of utilizing the results of the investigation for diagnostics of a cylindrical plasma.
{"title":"Interaction between an obliquely incident plane electromagnetic wave and an electron beam in the presence of a static magnetic field of arbitrary strength","authors":"K. Wilhelmsson","doi":"10.6028/JRES.066D.044","DOIUrl":"https://doi.org/10.6028/JRES.066D.044","url":null,"abstract":"The interaction between an obliquely incident plane electromagnetic wave and an electron beam ls studied theoretically. A static magnetic field of arbitrary strength is assumed to be present in the axial direction. Machine computations made for the case of a cylindrical electron plasma show that resonances occur in the backscattering cross section as a function of the angle of incidence of the plane wave. The dependence of the resonance angles on the plasma frequency for fixed gyrofrequency suggests a possibility of utilizing the results of the investigation for diagnostics of a cylindrical plasma.","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115043485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A solution is given to the problem of representing the complex properties of ionospheric characteristics on a worldwide scale, including their diurnal variation, by numerical analysis of ionospheric data as they are obtained from a network of sounding stations, without prior hand operations. The problem is complicated by t wo basic difficulties : (1) the data are affected by noise (random fiuctuation) and (2) t he stations are irregularly positioned in the two space dimensions. The second difficulty is overcome by a general method for construct ing functions orthogonal relative to the distribution of t he stations. Spccial filtering proc esses are employed for t hc optimum separation of noise from real physical variations. The end product of the a nalysis is a table of numerical coeffi cients defining a function r (A, 0, I) of t hrec variables, latit ude (i--), longitude (0) and time (I), which can be used to compute the ionospheric characteristic at any desired location or instant of time. The method applies to any ionospheric characteristic; however, as a means of illustration we use in the present paper only the characteristic, monthly median of t he F2-layer critical frequency (fo F,).
{"title":"Representation of diurnal and geographic variations of ionospheric data by numerical methods","authors":"W. B. Jones, R. Gallet","doi":"10.6028/JRES.066D.043","DOIUrl":"https://doi.org/10.6028/JRES.066D.043","url":null,"abstract":"A solution is given to the problem of representing the complex properties of ionospheric characteristics on a worldwide scale, including their diurnal variation, by numerical analysis of ionospheric data as they are obtained from a network of sounding stations, without prior hand operations. The problem is complicated by t wo basic difficulties : (1) the data are affected by noise (random fiuctuation) and (2) t he stations are irregularly positioned in the two space dimensions. The second difficulty is overcome by a general method for construct ing functions orthogonal relative to the distribution of t he stations. Spccial filtering proc esses are employed for t hc optimum separation of noise from real physical variations. The end product of the a nalysis is a table of numerical coeffi cients defining a function r (A, 0, I) of t hrec variables, latit ude (i--), longitude (0) and time (I), which can be used to compute the ionospheric characteristic at any desired location or instant of time. The method applies to any ionospheric characteristic; however, as a means of illustration we use in the present paper only the characteristic, monthly median of t he F2-layer critical frequency (fo F,).","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125193609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
When radio rays pass through t he atmosphere, they are defoc Llsed due to its presence. This effect is measu red by the divergence coefficient a nd general formulas are derived for D1, the divergence coefficient of t he direct ray, and D" the divergence coefficient of the reflected rayassuming a smooth spherical earth . As examples, DI and Dz are shown for some typical cases with an "exponential" atmosphere (troposphere).
{"title":"Defocusing of radio rays by the troposphere","authors":"R. E. Wilkerson","doi":"10.6028/JRES.066D.047","DOIUrl":"https://doi.org/10.6028/JRES.066D.047","url":null,"abstract":"When radio rays pass through t he atmosphere, they are defoc Llsed due to its presence. This effect is measu red by the divergence coefficient a nd general formulas are derived for D1, the divergence coefficient of t he direct ray, and D\" the divergence coefficient of the reflected rayassuming a smooth spherical earth . As examples, DI and Dz are shown for some typical cases with an \"exponential\" atmosphere (troposphere).","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130004097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the forward scattering of radio waves in the lower ionosphere","authors":"T. Hagfors","doi":"10.6028/JRES.066D.042","DOIUrl":"https://doi.org/10.6028/JRES.066D.042","url":null,"abstract":"","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126371294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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