{"title":"Introduction to the Theory of VLF Propagation","authors":"J. Wait","doi":"10.1109/JRPROC.1962.288152","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288152","url":null,"abstract":"This paper is a self-contained exposition of the conventional theory of propagation of VLF radio waves. The model is a spherical earth surrounded by a concentric ionosphere. Although the model is highly idealized, the theory is still quite involved. The complexities arise from the long wavelengths inherent in such problems. In Section I the elementary geometrical or hop theory for VLF is considered. This includes a discussion of ionospheric reflection coefficients and the influence of multiple reflections. The validity of the model is established by a comparison with experimental data. In Section II, the diffractive corrections near the caustics of the ray systems are obtained. These provide a means to extend the theory to points near and beyond the horizon point for the individual hops or rays. In Section III, the waveguide mode theory is expounded. A number of approximations and simplifications are introduced in order to illustrate principles. References to more detailed analyses which use higher order approximations are given. Finally, in Section IV, the influence of a stratified ionosphere is treated by using a two-layer model. The material in this paper was included in the Summer (1961) Lecture Course on Radio Propagation given at the Boulder Laboratories of the National Bureau of Standards, and in earlier graduate courses, at the University of Colorado.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"6 1","pages":"1624-1647"},"PeriodicalIF":0.0,"publicationDate":"1962-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84745004","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":"Linear Decision Functions, with Application to Pattern Recognition","authors":"W. Highleyman","doi":"10.1109/JRPROC.1962.288194","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288194","url":null,"abstract":"Many pattern recognition machines may be considered to consist of two principal parts, a receptor and a categorizer. The receptor makes certain measurements on the unknown pattern to be recognized; the categorizer determines from these measurements the particular allowable pattern class to which the unknown pattern belongs. This paper is concerned with the study of a particular class of categorizers, the linear decision function. The optimum linear decision function is the best linear approximation to the optimum decision function in the following sense: 1) \"Optimum\" is taken to mean minimum loss (which includes minimum error systems). 2) \"Linear\" is taken to mean that each pair of pattern classes is separated by one and only one hyperplane in the measurement space. This class of categorizers is of practical interest for two reasons: 1) It can be empirically designed without making any assumptions whatsoever about either the distribution of the receptor measurements or the a priori probabilities of occurrence of the pattern classes, providing an appropriate pattern source is available. 2) Its implementation is quite simple and inexpensive. Various properties of linear decision functions are discussed. One such property is that a linear decision function is guaranteed to perform at least as well as a minimum distance categorizer. Procedures are then developed for the estimation (or design) of the optimum linear decision function based upon an appropriate sampling from the pattern classes to be categorized.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"54 1","pages":"1501-1514"},"PeriodicalIF":0.0,"publicationDate":"1962-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80933306","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":"Packaged Electronically Tunable S-Band Traveling-Wave Maser System","authors":"S. Okwit, J. Smith","doi":"10.1109/JRPROC.1962.288191","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288191","url":null,"abstract":"An S-band traveling-wave maser that operates over an 11 per cent tuning range is tuned by a single \"frequency-calibrated\" dial from 2120 to 2380 Mc. The maser has a relatively constant gain of 30 db and an instantaneous bandwidth of 22 Mc. It uses a comb-type slow-wave structure loaded on both sides with a 6 in length of 0.065 per cent chromium-doped ruby. Ferrimagnetic disks of yttrium iron garnet are periodically distributed in the slow-wave structure and provide sufficient reverse loss for short-circuit stability (100 db). A relatively high gain per unit length of active ruby was realized because of: 1) optimization of the C axis orientation with respect to the dc and RF magnetic fields, 2) utilization of a four spin flip cross-relaxation process and 3) loading both sides of the comb structure with active ruby. The traveling-wave maser and all the necessary auxiliary components have been packaged into an operational unit. The noise temperature of the system is about 10°K, and the short-term and long-term stabilities are ±0.05 db and ± 0.1 db, respectively. A series of detailed measurements on the important electrical characteristics are described, and the performance data is presented. The system has been designed and successfully tested to meet military field environmental specifications.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"16 1","pages":"1470-1483"},"PeriodicalIF":0.0,"publicationDate":"1962-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73306062","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":"The TFT A New Thin-Film Transistor","authors":"P. K. Weimer","doi":"10.1109/JRPROC.1962.288190","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288190","url":null,"abstract":"A thin-film transistor, TFT, fabricated by evaporation of all components on to an insulating substrate has been developed. Operation is based upon the control of injected majority carriers in a wide-band-gap semiconductor by means of an insulated control gate. Experimental units using microcrystalline layers of cadmium sulfide have yielded voltage amplification factors greater than 100, transconductances greater than 10,000 , μmho, input impedances greater than 106 Ω shunted by 50 pf and gain-bandwidth products greater than 10 Mc. Switching speeds of less than 0.1 μsec have been observed. Simple evaporated thin-film circuits incorporating the TFT have been built. Direct coupling between stages is permitted since the insulated gate electrode can be biased positively as well as negatively without drawing appreciable gate current. Modified forms of the TFT have been built for use as a flip-flop, an AND gate and a NOR gate in computer applications.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"43 1","pages":"1462-1469"},"PeriodicalIF":0.0,"publicationDate":"1962-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75378933","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":"Gross Errors in Height Indication from Pulsed Radar Altimeters Operating over Thick Ice or Snow","authors":"A. Waite, S. J. Schmidt","doi":"10.1109/JRPROC.1962.288195","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288195","url":null,"abstract":"Errors reported in 1946 by aircraft pilots using pulsed radar altimeters over Antarctic ice, coupled wih results of radio-wave propagation studies in both polar areas (1946-1955), led to measurements of the electrical characteristics of thick ice at high and ultra-high frequencies. These measurements produced information relative to dielectric constants, loss factors, scattering, and interface reflection data that subsequently permitted successful radio-wave penetration measurements in continental ice to depth of several hundred feet in both the Antarctic and the Arctic (1958-1960). Results indicated clearly that low-flying pilots relying on pulsed 440-Mc altimeters in poor visibility over thick ice can be fatally misled by errors inherent in these instruments. The paper presents recent data obtained by the Signal Corps pertinent to radio-wave transparency of thick ice and snow.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"6 1","pages":"1515-1520"},"PeriodicalIF":0.0,"publicationDate":"1962-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90905150","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":"A Simplified Stability Criterion for Linear Discrete Systems","authors":"E. Jury","doi":"10.1109/JRPROC.1962.288193","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288193","url":null,"abstract":"In this study a simplified analytic test of stability of linear discrete systems is obtained. This test also yields the necessary and sufficient conditions for a real polynomial in the variable z to have all its roots inside the unit circle in the z plane. The new stability constraints require the evaluation of only half the number of Schur-Cohn determinants [1], [2]. It is shown that for the test of a fourth-order system only a third-order determinant is required and for the fifth-order, one second-order and one fourth-order determinant are required. The test is applied directly in the z plane and yields the minimum number of constraint terms. Stability constraints up to the sixth-order case are obtained and for the nth-order case are formulated. The simplicity of this criterion is similar to that of the Lienard-Chipard criterion [3] for the continuous case which has a decisive advantage over the Routh-Hurwitz criterion [4], [5]. Finally, general conditions on the number of roots inside the unit circle for n even and odd are also presented in this paper.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"156 1","pages":"1493-1500"},"PeriodicalIF":0.0,"publicationDate":"1962-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86485395","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":"Modern Science and the Intellectual Tradition","authors":"G. Holton","doi":"10.1109/JRPROC.1962.288188","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288188","url":null,"abstract":"","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"2009 1","pages":"1452-1458"},"PeriodicalIF":0.0,"publicationDate":"1962-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88248934","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":"Microwave Communications","authors":"J. Vogelman","doi":"10.1109/jrproc.1962.288370","DOIUrl":"https://doi.org/10.1109/jrproc.1962.288370","url":null,"abstract":"An historical summary of the development of microwave communications is presented, together with an examination of the present state-of-the-art. The current research and development efforts are used to forecast the extension of the present applications and techniques into the future.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"62 1","pages":"907-911"},"PeriodicalIF":0.0,"publicationDate":"1962-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80488301","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":"Trends in Space Navigation","authors":"K. Satyendra","doi":"10.1109/JRPROC.1962.288115","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288115","url":null,"abstract":"The theme of this paper is based on the growing use of self-contained navigational systems in space navigation. A figure of merit, called the self-containment index (SCI), is defined in order to define quantitatively the degree of autonomy for which a system design is directed. The navigational problem of spacecraft is divided into problems of point-dynamics and rigid-body dynamics and the major factors are defined which deserve consideration in the understanding of the space navigational problem. Consistent with the requirements for low size, weight and power allocations and for very high accuracy and reliability tolerances, optical techniques are found ideally suited for space navigation. Open-loop and closed-loop methods of earth satellite navigation are presented and extended to the lunar navigation problem. Some advanced navigational concepts are given using nonrotating and track-while-scan instruments. The importance is emphasized of the increase in data-processing requirements and their part in accuracy enhancement through statistical techniques. A review of optical Doppler and lasers for measurement of distance and velocity is given. The concept of guidance management is proposed for consolidation of all the launch, orbital, midcourse, return and other guidance phases of a future multistage spacecraft into a single, integrated, selfcontained navigation system within the final upper stage.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"13 1","pages":"1362-1373"},"PeriodicalIF":0.0,"publicationDate":"1962-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85013496","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":"Fifty Years in Aeronautical Navigational Electronics","authors":"V. I. Weihe","doi":"10.1109/JRPROC.1962.288093","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288093","url":null,"abstract":"The state-of-the-art in aircraft operations and in radio technology for the very early period of aeronautical navigation is given, and the technical evolution during the first twenty-five years of IRE is covered. Policy and organizational problems of the transition to the second twenty-five-year period are mentioned. A discussion is given of the World War II system developments, the introduction of pulse techniques and the race toward the microwave portion of the spectrum. This is followed by a discussion of self-contained systems. Illustrations are provided covering some of the more fundamental spatial characteristics of electronic navigation systems.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"23 1","pages":"658-663"},"PeriodicalIF":0.0,"publicationDate":"1962-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85429576","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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