WorldCat Identities

SMYTH RESEARCH ASSOCIATES SAN DIEGO CALIF

Overview
Works: 14 works in 18 publications in 1 language and 18 library holdings
Publication Timeline
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Most widely held works by SMYTH RESEARCH ASSOCIATES SAN DIEGO CALIF
A STUDY OF PROPAGATION MEDIUM RF NOISE( Book )

3 editions published between 1963 and 1964 in English and held by 3 WorldCat member libraries worldwide

The effects of the propagation medium noise upon long distance, line-of-sight, tropospheric microwave circuits are examined. The propagation medium noise modulates the phase, amplitude, and angle of arrival of the signal. Based upon the limited amount of experimental data available, it is concluded that the phase noise (time frequency noise) will not be serious in the case of transmissions between fixed terminals if the video bandwidth is properly chosen. In particular, frequency components of less than 0.1 cps should be excluded by the video filter. The angle of arrival noise (space frequency noise) may become serious if fixed antennas with beamwidths of less than one degree are used. The amplitude modulation, which is apparently due to some sort of atmospherically modified multipath situation, lead to 25 db fades for a period of time which will be important for high reliability circuits. When one or both of the terminals are moving, the effects of the propagation medium noise should be considerably more serious. Experimental data for this case is extremely limited and numerical estimates are therefore very tentative. (Author)
TARGET ACCURACY EXPERIMENT( Book )

3 editions published between 1961 and 1964 in English and held by 3 WorldCat member libraries worldwide

The Earth's atmosphere distorts the radio view of space vehicles as seen from the earth's surface. The limitations placed on ones ability to position and locate objects in space as a consequence of this distortion is the subject of the reported investigations. A detailed experimental program was pursued to measure particularly the elevation angle errors incurred in making space target measurements from the earth's surface when viewing near the horizon. Signals originating in artificial earth satellites were viewed through the distorting atmospheric medium and analyses performed to define the observed distortions as a function of space, frequency, and time. (Author)
Experimental studies of e region field aligned scattering at vhf( Book )

1 edition published in 1961 in English and held by 1 WorldCat member library worldwide

Publications by the personnel of Smyth Research Associates( Book )

in English and held by 1 WorldCat member library worldwide

TRANSEQUATORIAL 'F' LAYER STUDY( Book )

1 edition published in 1966 in English and held by 1 WorldCat member library worldwide

Three months' data have been collected in a study of transequatorial F-layer radio propagation in the Far East. Three 24-hour transmissions per week are made from Okinawa on frequencies from 34 to 90 MHz and received at Darwin, Australia and Lautoka, Fiji Islands. The Okinawa - Darwin path is 4,300 km long, symmetrically displaced about the magnetic equator; it lies in a magnetic meridian plane. The Okinawa - Fiji path is 7,300 km long and cuts across the magnetic equator at an angle of 36 degrees. The months of December 1965, and January and February 1966 were typical of the solstice period -- regular midday reception on both paths on 34 MHz but little activity on the higher frequencies. Occasional VHF openings occurred at Darwin but seldomly at Fiji. With the approach of the equinox, March provided a dramatic increase of VHF activity at Darwin with frequent nighttime transmission of frequencies up to 77 MHz. Fiji VHF reception has also become more active but on a reduced scale relative to Darwin -- only one case of 54 MHz reception to date. The CW recording is working well with reliable acquisition of signals every time an opening occurs. Fair success has been achieved with the special experiments aimed at propagation mode identification. Pulse resolution of multipaths and angle of arrival measurement are producing results but need further development. (Author)
Multipath problems in radio frequency transmission systems( Book )

1 edition published in 1967 in English and held by 1 WorldCat member library worldwide

The phase characteristics of incoherent multipath reflection between airborne and ground-based terminals was examined. Measurements were made on calm overwater paths at frequencies of 2.735 and 8.205 GHz. No significant differences in the measured phase spectra are noted for the two frequencies of measurement or with propagation direction relative to sea surface wave structure. The measured phase spectra decreases at a rate of 3 to 5 db per octave in the 100- to 1,000-Hz band. Maximum phase modulation indexes observed are 10 degrees rms phase deviation within the 100- to 2,000-Hz band. This phenomenon probably does not present an important limitation to data-link reliability. (Author)
TRADEWIND DUCTING( Book )

1 edition published in 1965 in English and held by 1 WorldCat member library worldwide

An experimental research program is described in this report. The experiment was conducted to gain additional information on the Tradewind Duct mode for VHF communications over the 2500 mile path between Hawaii and Point Buchon on the central California coast. Medium power TV transmitters situated at Maui and Hilo were used as the source, and SRA - 506 phase-locked receivers and medium to high gain antennas were used at the receiving site. Multiple frequencies between 60 and 212 mc/s were used. Data concerning the signal strength versus time, height gain at the receiving terminal, and meteorological data along the path were obtained. This report describes the seasonal and diurnal duty cycle of the ducting mode of propagation and the fading rate and fading depth of the signal received. Correlation between the transmission loss and duty cycle and the meteorological data yields information on the feasibility of predicting this propagation mode. The cumulative distributions of the basic transmission losses are displayed. (Author)
Shield method for solution of geometric problems involving reflection from field aligned ionization. volume ii( Book )

1 edition published in 1961 in English and held by 1 WorldCat member library worldwide

Shield method for solution of geometric problems involving reflection from field aligned ionization. volume i( Book )

1 edition published in 1961 in English and held by 1 WorldCat member library worldwide

Micro-meteorological measurements by means of sound; final report by Calif.) Smyth Research Associates (San Diego( Book )

1 edition published in 1961 in English and held by 1 WorldCat member library worldwide

A study of magnetic field-aligned scatter( Book )

1 edition published in 1962 in English and held by 1 WorldCat member library worldwide

Final preparations for the UHF Caribbean propagation experiments are described. Flight tests and studies of the ground station antenna system completed the engineering preparations. The Panama and Curacao experiments will be performed next quarter. (Author)
Atmospheric refraction effects on precision radar tracking( Book )

1 edition published in 1961 in English and held by 1 WorldCat member library worldwide

This report describes atmospheric effects on the three important radar tracking parameters; elevation angle error, range error and doppler error. The results of experimental sea-interferometer measurements using radio satellites are compared with those predicted on the basis of routine refractive index data. It is shown that observed elevation angle error usually exceeds predicted values by about 1.5 milliradians at 1 deg elevation angle and about 0.3mr at 8.5 deg elevation angle. Range error fluctuations are as much as 30 meters at 108mc. Doppler errors are of the order of a few cps at 108mc, at low elevation angles. Appendices are included, which describe in detail the computational methods for elevation angles of sea-interferometer minima, doppler frequency shift, and prediction of refractive effects using routine refractive index data. (Author)
Micro-meteorological measurements by means of sound( Book )

1 edition published in 1960 in English and held by 1 WorldCat member library worldwide

This study deals with the investigation of the scale and spectra of the turbulent fluctuations over an extended range in the lower atmosphere by means of sound propagation measurements. The measurements were carried out using singleengine, low-flying jet aircraft as the source of sound and the reception at the ground was accomplished by acoustical transducers in horns which were pointed vertically. The analysis of the data was performed by studying several discrete frequencies in the range from 500 to 2000 cycles per sec. It is concluded that sound propagation measurements are a feasible means of evaluating atmospheric turbulence characteristics. (Author)
Method of locating atmospheric-scatter and ob stacle-gain signal sources( Book )

1 edition published in 1961 in English and held by 1 WorldCat member library worldwide

Investigation of the possibilities existing with in the present state of the art for determining the location of equipments designed to operate on atmospheric-scatter including tropospheric scatter, d obstacle-gain principles from meas urements of the radio signals made at points be yond the line of sight such that the radiated electromagnetic signals from the equipment have suffered reflection, diffusion, scatter and re fraction by the propagation media. (Author)
 
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Audience level: 0.97 (from 0.63 for Micro-mete ... to 0.99 for A STUDY OF ...)

Languages
English (18)