At mospheric refract ion errors in heigh t finding radars ar c studied by means of detailed r efract ion calculations for a wid e range of meteorological conditions. For targets up to 70,000 feet a bove ground and 150 miles ground distance from t he radar site, t he mean height e rror was found to be as mu ch as 5,000 feet with a standa rd deviation of 1,200 feet. A correction for t he surface value of t he refractive index at t he radar s ite would eliminate t he mean height error and reduce the max imum standard dev iation to less t ha n 900 feet. An additional co rrec t ion for t he init ial grad ient of the refract ive index and t he value of t he r efract ive index at one ki lometer above t he surface would reduce t he maximum standard deviat ion lo less t ha n 400 feet . Methods of correcting he igh t errors based on available meteo rolog ical data a rc prese nted an d shown to be operationally practical.
{"title":"Correction of atmospheric refraction errors in radio height finding","authors":"W. B. Sweezy, B. Bean","doi":"10.6028/JRES.067D.017","DOIUrl":"https://doi.org/10.6028/JRES.067D.017","url":null,"abstract":"At mospheric refract ion errors in heigh t finding radars ar c studied by means of detailed r efract ion calculations for a wid e range of meteorological conditions. For targets up to 70,000 feet a bove ground and 150 miles ground distance from t he radar site, t he mean height e rror was found to be as mu ch as 5,000 feet with a standa rd deviation of 1,200 feet. A correction for t he surface value of t he refractive index at t he radar s ite would eliminate t he mean height error and reduce the max imum standard dev iation to less t ha n 900 feet. An additional co rrec t ion for t he init ial grad ient of the refract ive index and t he value of t he r efract ive index at one ki lometer above t he surface would reduce t he maximum standard deviat ion lo less t ha n 400 feet . Methods of correcting he igh t errors based on available meteo rolog ical data a rc prese nted an d shown to be operationally practical.","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1963-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125943696","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":"Sunset and sunrise in the ionosphere: effects on the propagation of longwaves","authors":"J. Rieker","doi":"10.6028/JRES.067D.016","DOIUrl":"https://doi.org/10.6028/JRES.067D.016","url":null,"abstract":"","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"520 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1963-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116265857","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}
This paper is co nce rned wit h the synthesis of a rad iation pattern in an eq uatorial p la ne s urrounding an infini te circu lar cy linder. A discussion of t he rad iation fi eld a bout s uch a c y linder leads to t he conclusion t hat a leaky-wave ante nn a can be ut ilized to provide the proper aperture d ist ribu t ion. Wi t h ka chosen sufficien t ly large to e nsure that prior theory concern ing t he inductive s lleet leaky-wave antenn a will apply, a Chebyshev distribut ion is a na lyzed . It is s hown that t he order of t he Chebys hev polynomina l mu st sat isfy N < ka cos "'0 sin 5N , wh er e
{"title":"Pattern synthesis with a flush-mounted leaky-wave antenna on a conducting circular cylinder","authors":"A. Ishimaru, Frederick R. Beich","doi":"10.6028/JRES.066D.076","DOIUrl":"https://doi.org/10.6028/JRES.066D.076","url":null,"abstract":"This paper is co nce rned wit h the synthesis of a rad iation pattern in an eq uatorial p la ne s urrounding an infini te circu lar cy linder. A discussion of t he rad iation fi eld a bout s uch a c y linder leads to t he conclusion t hat a leaky-wave ante nn a can be ut ilized to provide the proper aperture d ist ribu t ion. Wi t h ka chosen sufficien t ly large to e nsure that prior theory concern ing t he inductive s lleet leaky-wave antenn a will apply, a Chebyshev distribut ion is a na lyzed . It is s hown that t he order of t he Chebys hev polynomina l mu st sat isfy N < ka cos \"'0 sin 5N , wh er e <Po is t he angle of radiat ion measured fro m a nor mal to t he cylinder surface, a nd ON is the m ax imum deviat ion from t his a ngle . The radiation angle is given by <po= arc s in ({3 / k), w here (3 is a constant which is t he phase factor of an X-ba nd wa veguid e. Experi m ental work wi th s uch a waveguide, curved in t he H pla ne and flu sh-mounted in a fini te cylind er wi t h ka = 12.\"., provided radiat ion patterns which closely adhered to t he t heoretical analysis in the frequency range 8 .4 to 11.5 Gc/s.","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129047556","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}
This paper contains the r esults of studies performed during the last several years on t he short-term variability of t ropospheric signals received over within-the-horizon paths in Colorado and California. Signal variations of the type observed over such paths have been t ermed "prolonged space-wavE' fadeouts." They are analyzed as a function of carrier frequency, path characteristics, and meteorological parameters. The study also includes an evaluation of fadeouts observed over a path using a mountain peak as a diffracting knife-edge obstacle between transmitter and receiver. Principal results show a stronger diurnal trend of fadeout incidence in continental climates than in ma ritirne climates. A significant dependence of t he fadeout characteristics on the refractive index structu re has been observed in maritime climates. In general , fadeouts tend to be more frequent but of shorter duration for higher frequenci es. There are also indications that the occurrence of fadeout is well co rrelated on vertically spaced antennas. Thus, conventional space divers ity t echniques may not be effective to in crease the reliability of systems operating over within-the-horizon paths.
{"title":"Prolonged space-wave fadeouts in tropospheric propagation","authors":"A. Barsis, Marylinda Johnson","doi":"10.6028/JRES.066D.067","DOIUrl":"https://doi.org/10.6028/JRES.066D.067","url":null,"abstract":"This paper contains the r esults of studies performed during the last several years on t he short-term variability of t ropospheric signals received over within-the-horizon paths in Colorado and California. Signal variations of the type observed over such paths have been t ermed \"prolonged space-wavE' fadeouts.\" They are analyzed as a function of carrier frequency, path characteristics, and meteorological parameters. The study also includes an evaluation of fadeouts observed over a path using a mountain peak as a diffracting knife-edge obstacle between transmitter and receiver. Principal results show a stronger diurnal trend of fadeout incidence in continental climates than in ma ritirne climates. A significant dependence of t he fadeout characteristics on the refractive index structu re has been observed in maritime climates. In general , fadeouts tend to be more frequent but of shorter duration for higher frequenci es. There are also indications that the occurrence of fadeout is well co rrelated on vertically spaced antennas. Thus, conventional space divers ity t echniques may not be effective to in crease the reliability of systems operating over within-the-horizon paths.","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"176 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131081793","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}
In the preceding paper , t he authors have presented an asympto tic solution for t he fi eld in the illuminated region of a large circula r cylinder whose s urface impedance a round t he periph ery deviates from a constant value by a s inusoida l variation of small ampli t ude ." . T o 0 (.,,) , t he r eflected fi eld co mprises a specula rly reflected ray a nd two first-order diffracted rays ch aracteristic of a curved convex reflection grating. If the surface impeda nce varies " slowly," these t hree r ays can be combined in to a single spec ularly r eflected ray hav ing a reflection coeffi cien t which depends solely o n t he local impeda nce at the reflection point. The " slowness" co ndi t ions necessary for t he validity of th is local reflect ion prin ciple of geometrical optics a rc investigated a nd interprcted in ph ys ical term s. The resul ts a re presented in a ma nn er which suggests t heir appli cab ili ty to ge nera l, gently curved surfaces with slowly vary in g impedance propert ies.
{"title":"On the limitations of geometrical optics solutions for curved surfaces with variable impedance properties","authors":"C. J. Marcinkowski, L. Felsen","doi":"10.6028/JRES.066D.070","DOIUrl":"https://doi.org/10.6028/JRES.066D.070","url":null,"abstract":"In the preceding paper , t he authors have presented an asympto tic solution for t he fi eld in the illuminated region of a large circula r cylinder whose s urface impedance a round t he periph ery deviates from a constant value by a s inusoida l variation of small ampli t ude .\" . T o 0 (.,,) , t he r eflected fi eld co mprises a specula rly reflected ray a nd two first-order diffracted rays ch aracteristic of a curved convex reflection grating. If the surface impeda nce varies \" slowly,\" these t hree r ays can be combined in to a single spec ularly r eflected ray hav ing a reflection coeffi cien t which depends solely o n t he local impeda nce at the reflection point. The \" slowness\" co ndi t ions necessary for t he validity of th is local reflect ion prin ciple of geometrical optics a rc investigated a nd interprcted in ph ys ical term s. The resul ts a re presented in a ma nn er which suggests t heir appli cab ili ty to ge nera l, gently curved surfaces with slowly vary in g impedance propert ies.","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"137 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116051300","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}
Equations describing the propagation of radio waves in a horizontally stratified aniso tropic ionosphere were developed by considering the limit.ing case of a large number of in finitesimally thin slabs of constant electron density a nd collision frequency. The quasi longitudinal approximation was used. The propagation equations appeared as four coupled first-order linear differential equations, coupled by gradients in electron density and collision frequency. The quasi-longitudinal approximation permitted use of particularly simple forms for t he coupling coefficients, t hese forms being amenable to simple analysis. Coupling between two ordinary or two extraordinary modes was found to be considerably stronger than cross coupling between ordinary and extraordinary mode . Cross coupling was related to the rate of change of the direction of the phase normal. It was found that the reflection of VLF radio waves from t he daytime ionosphere is relatively insensitive to t he angle of incidence on the ionosphere except for highly oblique propagation. "Vhistler penetration was also found to be insensitive to the angle of incidence on the ionosphere.
{"title":"Very-low-frequency radio propagation in the ionosphere","authors":"D. Swift","doi":"10.6028/JRES.066D.066","DOIUrl":"https://doi.org/10.6028/JRES.066D.066","url":null,"abstract":"Equations describing the propagation of radio waves in a horizontally stratified aniso tropic ionosphere were developed by considering the limit.ing case of a large number of in finitesimally thin slabs of constant electron density a nd collision frequency. The quasi longitudinal approximation was used. The propagation equations appeared as four coupled first-order linear differential equations, coupled by gradients in electron density and collision frequency. The quasi-longitudinal approximation permitted use of particularly simple forms for t he coupling coefficients, t hese forms being amenable to simple analysis. Coupling between two ordinary or two extraordinary modes was found to be considerably stronger than cross coupling between ordinary and extraordinary mode . Cross coupling was related to the rate of change of the direction of the phase normal. It was found that the reflection of VLF radio waves from t he daytime ionosphere is relatively insensitive to t he angle of incidence on the ionosphere except for highly oblique propagation. \"Vhistler penetration was also found to be insensitive to the angle of incidence on the ionosphere.","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115824525","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}
In a p revious publication, a t wo-dimensional Green's fun ction has been deriv ed for a c ircula r cylinder whose su rface impedance aroun d t he peripher y deviates from a constan t value by a s inusoidal va riation of small amplit ude u. H ere, t his solut ion is eva luated asymptoticall y in t he illuminated region under t he assumpt ion t hat t he cylinder radius is la rge co mpared with Lhe wavelength of t he in ciden t fi eld . The asymptotic resul t is i nte rpreted. in te rms of geometrica~ opt ics generalized to ap ply to cylindrically curved, convex reflect ion grat ings, and comprIses t he first a nd higher-o rder diffracted rays associated wit h a plane grating, together with geometrical divergence coe ffi cien ts acco unting fo r t he surface curvature. Genera l properties of the spectru m of reflected rays a re observed . T he behav ior of t he firs t-order diffracted rays, a nd in part icular t heir domain of ex isten ce as a fUllet ion of s urface pe riod icity, is discussed in detail.
p revious出版物,t wo-dimensional格林有趣引发反应一直引出ed c ircula r汽缸的苏rface阻抗由于t他peripher y背离一个常量值的年代inusoidal va riation小乌德amplit u。H之前,t他的处理措施是伊娃luated asymptoticall y在t他照亮地区t他assumpt离子t hat圆柱半径是洛杉矶rge公司试管t他的摘要Lhe波长ciden t存在误伤。渐近的结果是不可逆的。从几何角度出发，将光学推广应用于圆柱弯曲、凸反射离子光栅，包括与平面光栅相关的一阶和高阶衍射光线，以及计算表面曲率的几何发散系数。对反射光线光谱的一般性质进行了观察。详细讨论了一阶T -衍射射线的行为，特别是它们作为5个表面周期函数的存在域的行为。
{"title":"On the geometrical optics of curved surfaces with periodic impedance properties","authors":"C. J. Marcinkowski, L. Felsen","doi":"10.6028/JRES.066D.069","DOIUrl":"https://doi.org/10.6028/JRES.066D.069","url":null,"abstract":"In a p revious publication, a t wo-dimensional Green's fun ction has been deriv ed for a c ircula r cylinder whose su rface impedance aroun d t he peripher y deviates from a constan t value by a s inusoidal va riation of small amplit ude u. H ere, t his solut ion is eva luated asymptoticall y in t he illuminated region under t he assumpt ion t hat t he cylinder radius is la rge co mpared with Lhe wavelength of t he in ciden t fi eld . The asymptotic resul t is i nte rpreted. in te rms of geometrica~ opt ics generalized to ap ply to cylindrically curved, convex reflect ion grat ings, and comprIses t he first a nd higher-o rder diffracted rays associated wit h a plane grating, together with geometrical divergence coe ffi cien ts acco unting fo r t he surface curvature. Genera l properties of the spectru m of reflected rays a re observed . T he behav ior of t he firs t-order diffracted rays, a nd in part icular t heir domain of ex isten ce as a fUllet ion of s urface pe riod icity, is discussed in detail.","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125361022","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}
spherically symmetric refractivity which varies exponentially with height. The correction is given as function of surface refractivity and ray elevation angle, and its accuracy and limitations are disc ussed. In the long-range tracking of an object in space by an observer on the earth, systematic errors are introduced by the earth's atmosphere, most of the contribution arising from the troposphere at micro wave frequencies. This paper derives an explicit analytic expression for the tropospheric range e1'1'or for a standard atmosphere whose refractivity is exponentially distributed with height. If one measures the delay
{"title":"RANGE-ERROR COMPENSATION FOR A TROPOSPHERE WITH EXPONENTIALLY VARYING REFRACTIVITY","authors":"J. Freeman","doi":"10.6028/JRES.066D.068","DOIUrl":"https://doi.org/10.6028/JRES.066D.068","url":null,"abstract":"spherically symmetric refractivity which varies exponentially with height. The correction is given as function of surface refractivity and ray elevation angle, and its accuracy and limitations are disc ussed. In the long-range tracking of an object in space by an observer on the earth, systematic errors are introduced by the earth's atmosphere, most of the contribution arising from the troposphere at micro wave frequencies. This paper derives an explicit analytic expression for the tropospheric range e1'1'or for a standard atmosphere whose refractivity is exponentially distributed with height. If one measures the delay","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115290754","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}
Ionospheric electron density profiles obtained by the cw propagation technique and by rf impedance probe techniques
用连续波传播技术和射频阻抗探针技术获得电离层电子密度分布图
{"title":"RF IMPEDANCE PROBE MEASUREMENTS OF IONOSPHERIC ELECTRON DENSITIES","authors":"J. A. Kane, J. Jackson, H. Whale","doi":"10.6028/JRES.066D.064","DOIUrl":"https://doi.org/10.6028/JRES.066D.064","url":null,"abstract":"Ionospheric electron density profiles obtained by the cw propagation technique and by rf impedance probe techniques","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":"1962-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130560300","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":"Conversion of the amplitude-probability distribution function for atmospheric radio noise from one bandwidth to another","authors":"A. Spaulding, C. J. Roubique, W. Q. Crichlow","doi":"10.6028/JRES.066D.071","DOIUrl":"https://doi.org/10.6028/JRES.066D.071","url":null,"abstract":"","PeriodicalId":398550,"journal":{"name":"Journal of Research of the National Bureau of Standards, Section D: Radio Propagation","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117037721","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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