WorldCat Identities

LINCOLN LAB MASS INST OF TECH LEXINGTON

Overview
Works: 59 works in 60 publications in 1 language and 63 library holdings
Genres: Observations 
Classifications: TK7855.M41,
Publication Timeline
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Most widely held works by LINCOLN LAB MASS INST OF TECH LEXINGTON
Generation of planetary ephemerides on an electronic computer by M. E Ash( Book )

1 edition published in 1965 in English and held by 2 WorldCat member libraries worldwide

A computer program, called the Planetary Ephemeris Program (PEP), is being written at Lincoln Laboratory. The purpose of the program is to improve planetary and lunar ephemerides using the results of radar and optical observations. In this report, the author derives the differential equations that are numerically integrated in PEP to determine as functions of time the positions and velocities of the planets, of the Earth-Moon barycenter and of the Moon, and the partial derivatives of these positions and velocities with respect to initial conditions, masses and other parameters. Newtonian theory with the usual unrigorous general relativistic corrections is employed. The equations of motion and the equations for the partial derivatives with respect to initial conditions are presented in the form needed in the Encke's method of integration used in PEP. (Author)
Lincoln experimental terminal antenna system by B. F LaPage( Book )

1 edition published in 1965 in English and held by 2 WorldCat member libraries worldwide

The Lincoln Experimental Terminal (LET) is a small transportable ground terminal for testing and evaluating space communications techniques. The requirements, design analysis, and performance data for the LET antenna and feed system are described. The 15-foot -aperture antenna has Cassegrainian optics, and a conical-horn-reflector feed exciter producing opposite-hand circularly polarized transmitting and receiving beams. The simultaneous operation of a two-channel tracking system is also discussed. (Author)
GENERAL RESEARCH( Book )

2 editions published between 1965 and 1966 in English and held by 2 WorldCat member libraries worldwide

This Quarterly Technical Summary covers the period from 1 February through 30 April 1969. It consolidates the reports of Division 2 (Data Systems), Division 4 (Radar), Division 5 (Optics), Division 7 (Engineering), and Division 8 (Solid State) on the General Research Program at Lincoln Laboratory. (Author)
Electrodeposited magnetic film development( Book )

1 edition published in 1965 in English and held by 2 WorldCat member libraries worldwide

The report describes the development of a closed flux structure which incorporates a plated copper conductor in a thin permalloy sheet. The work included the production of large area samples of high coercivity film uniformly plated on a ground plane structure but separated from it by pinhole free insulation. (Author)
The effect of pseudorandom frequency hopping on the probability of simultaneous usage of a communication satellite by J. U Beusch( Book )

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

When the up-link frequency band repeated by a communications satellite is hopped in a periodic manner, when users are divided so that a group of them can transmit only when a particular frequency band is repeated, and when message arrivals for one user are independent of message arrivals for any other user, the users in a group are independent. When the frequency hopping is done in a pseudorandom rather than a periodic manner, the users are dependent. The effect of the dependence is, in practical cases, to increase the probability of there being a large number of simultaneous users which increases the probability of system overload. General expressions for the probability of system overload and for the fraction of the information lost due to overload are obtained. These expressions illustrate the effect of the dependence induced by the pseudorandom frequency hopping. Examples are presented. (Author)
The Haystack Computer control system by F. E Heart( Book )

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

The 120-foot-diameter Haystack antenna operates at X-band and is used for satellite communications, radio astronomy, and radar astronomy. Haystack will be used to study stars, planets, the sun, the moon, and earth satellites. In order to point the antenna to within 1/10 beamwidth (22 seconds of arc) and to provide flexible control and data processing for diverse users, a digital computer has been tightly integrated into the control system. The parameters of an experiment and computer control are arranged via simple operator discourse through a keyboard/printer. The computer system can simultaneously direct the antenna, process receiver signal data, drive convenient operator displays, and permit operator discourse. Thus, processed signal data may be observed in real time, and modifications to the experiment may be rapidly implemented. The computer control system has been completed and is in full operation. (Author)
Magnetic studies of the antiferromagnetic RbMnF₃ by W. J Ince( Book )

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

Magnetic properties of the antiferromagnet RbMnF3 were studied. Below T sub N, the magnetic ions order into a two-sublattice system with the spins antiparallel. RbMnF3 exhibits high exchange and low anisotropy; the form of the anisotropy surface is cubic. Consequently, for applied DC magnetic fields less than about 3000 oe, the static equilibrium position of the sublattice magnetization is, in general, multivalued. Measurements of the DC susceptibility chi were made on powder and single crystal specimens of RbMnF3 for the range of applied field 0 to 12 koe and over the temperature range 4.2 to 300K. The observed value of T sub N was about ten degrees higher than the previously published value. When plotted as a function of applied field, chi sub(111) shows no abrupt discontinuity analogous to the spin flopping exhibited by uniaxial antiferromagnets. A simple model, in which H sub DC and M are restricted to the (110) plane, has enabled solutions of the static equilibrium problem to be obtained. X-band resonance experiments are reported, and a resonance theory is presented which incorporates the equilibrium solutions. The predicted antiferromagnetic resonance spectrum shows reasonable agreement with the experimental data. (Author)
A shaped reflector as a primary feed for haystack by A Sotiropoulos( Book )

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

The paper describes a technique for obtaining high aperture efficiency in the Haystack 120-foot diameter Cassegrain antenna system. The approach used seeks to maximize the percentage of power intercepted by the hyperboloidal subreflector of the Cassegrain antenna system by shaping its primary feed radiation pattern. The primary feed configuration is a linearly polarized waveguide feed illuminating a specially shaped reflector. A number of theoretical antenna models were calculated and one of these antennas (a 30 wavelength diameter shaped reflector at 7750 Mcps) was fabricated and evaluated. Calculated estimates of percentage of primary feed power intercepted by the subreflector and Cassegrain aperture efficiency are presented. (Author)
12-horn monopulse antenna system for millstone hill radar by Charles A Lindberg( Book )

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

The 440-Mcps conical-scan tracker at the Millstone Hill radar site has been converted to an L-band 12-horn monopulse tracker utilizing a Cassegrain optics reflector system. The amplitude sensing monopulse feed illuminates a 10-foot subreflector and thence an 84-foot-diameter paraboloid with linear or either sense of circular polarization. This system conversion increased the capabilities of the radar complex in that higher antenna gain and increased tracking sensitivity are obtained. The merits of the 12-horn system have been proven with actual results substantiating the theoretical predictions. This report discusses the design considerations and final performance characteristics of the overall antenna system and its individual components. (Author)
Lincoln experimental terminal training and frequency control( Book )

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

The Lincoln Experimental Terminal timing and frequency control provides digital control signals to the frequency synthesizers which determine transmit and receive frequencies and system timing signals to such equipment as the sequential encoder-decoder and the sync recovery system. Every 200 Msec a new 15-bit frequency control word is sent to the transmit and receive synthesizers, the transmit word containing the information signal plus one-way doppler prediction superimposed on the frequency-hopped base frequency, and the receive word containing one-way doppler prediction plus measured frequency error superimposed on the base frequency. Every 5 ms a sync signal is substituted for the information signal in the transmit word and a separate frequency control word is sent to the sync receiver frequency synthesizer. Timing of all output signals is variable in response to predicted path delay and measured time error. (Author)
Gunn effect in compound semiconductors by Arthur G Foyt( Book )

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

A theoretical and experimental study of the Gunn effect is presented. It appears that this effect, originally observed by Gunn as a time variation in the current through ohmic samples of n-GaAs when the sample voltage exceeded a critical value, can be accounted for by the transferred electron model of Ridley and Watkins. This model is based on a transfer of electrons from a low-mass, high-mobility conduction band that is lowest in energy to a higher-mass, low-mobility band as the electron temperature is increased by the applied electric field. If the transfer occurs rapidly enough as the electric field is increased, a bulk differential negative resistance will be realized, which then leads to the formation of domains of different electrical conductivity which move through the sample, giving rise to a time-varying current. The Gunn effect was also observed in n-CdTe, and resistance vs hydrostatic pressure experiments show that the transferred electron model is a reasonable explanation for this material as well. Finally, the absence of an instability in n-InSb and n-InAs is shown to be consistent with the transferred electron model. (Author)
Space radiation effects on high gain low current silicon planar transistors by A. G Stanley( Book )

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

The availability of silicon planar transistors with DC gains up to 300 at 10-microamps collector current has made it possible to design circuits with very low power consumption. By irradiating a number of commercial types with 1.5 Mev electrons in different circuit configurations, they were shown to be rather susceptible to space radiation. The most sensitive parameters are leakage current and low current gain. The effect on saturation voltages and on matching characteristics of transistor pairs was found to be minor, as long as the DC gain did not fall below 10. Under prolonged irradiation at electron fluxes representative of the inner Van Allen belt most transistor types had leakage currents considerably less than 100nA at emitter-collector biases not exceeding 10V. A few types exhibited leakage currents as high as 500 microamps A due to the formation of surface channels. A total doese of 10 to the 15th power e/sq cm reduced the DC gain in the 5- to 10-microamps A range of most to the transistors to values between 5 and 20. The gain after irradiation was governed by recombination-generation in the base-emitter region, but did not depend significantly on the pre-irradiation gain. Encapsulation of the transistor chip in a dense plastic material proved to be an effective method of preserving the gain under irradiation with a minimum penalty in weight and volume. (Author)
Development of a large dynamic range tunnel diode amplifier for phased array receivers( Book )

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

An investigation was made to develop large dynamic range S-band tunnel diode amplifiers for phased array receivers. The report covers a reproducibility study of these amplifiers, and the investigation of amplifier characteristics pertinent to phased array applications. Three two-stage tunnel diode amplifiers were delivered to Lincoln Laboratory. These amplifiers operate at a center frequency of 2.85Gc/s =2%, have a 1.5dB bandwidth ranging from 400-450 Mc/s at a gain of 18.0 to 18.5 dB, and have a noise figure between 5.6 and 5.9 dB. The amplifiers are unconditionally stable, and their output power at the 1 dB compression point ranges from - 10.5 dBm to - 12 dBm. The phases of any two amplifiers track within =3 degrees over a band of 110-190 Mc/s, and the amplitudes track within =1/2 dB over a Band of 290-410 Mc/s. (Author)
The design of band separation filters by Alfred I Grayzel( Book )

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

A band separation filter is a network with one input and m outputs, each corresponding to a different portion of the frequency spectrum. When a voltage is applied to the input terminal, it will appear at one of the output terminals only slightly attenuated. The filter considered here is a lossless network with each output terminal terminated in a one ohm resistance. The further condition that the input impedance of this network equals 1 + j0 for all frequencies is imposed. In this thesis a sufficient condition for realizability on the m transfer impedances is derived. It is shown that Butterworth characteristics for each of the m transfer impedances can be achieved with networks synthesizable in ladder form. It is also shown that L filter characteristics are also realizable but that the synthesis procedure is more complicated and necessitates coupled coils. Normalized curves of the attenuation characteristics for each type are presented. The extension of this method to transmission line networks is discussed, and it is shown that the Butterworth characteristic can be achieved with this type of element. (Author)
Effect of night sky backgrounds on optical measurements by Robert O'B Carpenter( Book )

1 edition published in 1959 in English and held by 1 WorldCat member library worldwide

A review is given of the sources and magnitudes of the night sky backgrounds, from 0.3 to 5 microns particularly as they might interfere with the observation of the spectrum of a small missile re-entering the atmosphere. Distributions of stellar magnitude and color, zodiacal and galactic scattered light, air glow, twilight, moonlight, and man-made lighting are discussed. Application is made of the background magnitude data to estimate the limitation of the threshold of large telescope-spectrometers using 1P21, PbS, and other detectors. Objective and slit-type spectrographs are considered, including the requirements for, and effect of, tracking precision. (Author)
A review of long-range earth strain measurement techniques for providing earthquake warning by E Gehrels( Book )

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

One of the most valuable tools for studying earthquakes and faults is earth strain or displacement measurements. Geologists are now looking for minute telltake displacements that might occur before an earthquake. This report discusses the possible accuracies that might be achieved by three different electromagnetic measurement techniques: (1) Microwave phase measurements, (2) Modulated light beams, and (3) Laser interferometers. The first is extremely sensitive to propagation errors. The second can achieve a modest degree of accuracy, 10 to the -7th power or better, and will clearly meet the minimum requirements. The third will provide by far the greatest degree of accuracy for propagation path lengths over which at least a partial degree of coherence of the wave front can be maintained. (Author)
Geometry and patterns of large aperture seismic arrays by R. T Lacoss( Book )

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

A study of possible configurations for a Large Aperture Seismic Array has been completed. An array having 21 identical subarrays located on three concentric circles has been found to yield the most satisfactory pattern in wave number space of all the configurations tested. Patterns for some alternative placements of subarrays, including that of the experimental LASA in Montana, have been included in this report. This study of patterns in wave number space has yielded the suggestion that a LASA having a diameter of 200 km should be composed of subarrays from 10 to 15 km in diameter. Such an increase of subarray size above the 7 km diameter subarrays of the experimental LASA would require the use of less regular subarray geometries than those which have been used in Montana. A sensitivity function for patterns has been developed. This function can be used to predict the change in patterns which might result from changes in seismometer or subarray positions. Since the sensitivity function predicts possible changes in patterns, it can be used to set bounds upon changes in an array which can be made without severely changing the pattern. The tight bounds imposed by the sensitivity function can be relaxed if the pattern resulting from any anticipated change in position is actually computed. Since very little computer time is required to compute a pattern, this procedure is highly recommended. (Author)
On-line graphical specifications of computer procedures by W Sutherland( Book )

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

A promising area of application for recently developed computer graphics techniques is computer programming. Two important considerations in using an interactive graphics system for drawing programs are (1) the form of a pictorial programming notation and (2) methods for making a computer execute the program once drawn. These topics are discussed in the context of an experimental graphical programming system running on the Lincoln Laboratory TX-2 Computer. This system uses a block notation for programs and can execute the drawn program with an interpreter. Improved graphical input languages for drawing programs and program notations which combine appropriate features of pictorial and written languages are needed before applications in this area are practical. The benefits to be expected from a graphical approach to programming include (1) automatic documentation, (2) debugging assistance, and (3) natural expression of parallel processes. (Author)
Haystack display translator by S. B Russell( Book )

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

The Haystack Display Translator provides decimal displays of the Haystack antenna azimuth and elevation position angles, command azimuth and elevation angles, azimuth and elevation bias angles, or alternately, azimuth and elevation center of scan angles, and EST and GMT displays. Each of the 19-bit binary angle inputs is multiplied by a scale factor, converted from binary to BCD, and stored for display. EST in BCD is stored for display and also converted to GMT and stored for display. (Author)
DIGITAL FILTER DESIGN TECHNIQUES by Charles M Rader( Book )

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

Digital filtering is the process of spectrum shaping using digital components as the basic elements. Increasing speed and decreasing size and cost of digital components make it likely that digital filtering, already used extensively in the computer simulation of analog filters, will perform, in real-time devices, the functions which are now performed almost exclusively by analog components. In this paper, using the z-transform calculus, several digital filter design techniques are reviewed, and new ones are presented. One technique can be used to design a digital filter whose impulse response is like that of a given analog filter; another technique is suitable for the design of a digital filter meeting frequency response criteria. A third technique yields digital filters with linear phase, specified frequency response, and controlled impulse response duration. The effect of digital arithmetic on the behavior of digital filters is also considered. (Author)
 
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English (21)