M-ary Poisson detection and optical communications.
M-ary detection for optical communication investigated for maximum likelihood detection of one of M Poisson processes in background noise
Gagliardi, R. M.↗
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Performance of self-synchronized PSK systems.
Error probability bounds for self synchronized binary PSK communication systems, simulating decision feedback, phase doubling and maximum likelihood systems
Oberst, J. F.↗
Maximum likelhood identification of stochastic linear systems
Maximum likelihood identification of stochastic linear systems
Kashyap, R. L.↗
A review of some results on the design of signals for Gaussian noise and intersymbol interference immunity
Signal design for Gaussian noise and intersymbol interference immunity, discussing bandlimited signals and maximum likelihood detection technique
Simon, M. K.↗
Performance of self-synchronized phase-shift keyed systems
Error probability upper and lower bounds determined for self synchronized binary PSK communications systems, presenting maximum-likelihood and Monte Carlo computer simulation
Oberst, J. F.↗
Discrete-component S-band power amplifier
Amplifier uses low Q input and output circuitry incorporating four variable air dielectric capacitors. Performance over conventional designs includes - increased power output, decreased likelihood of parametric oscillation, and increased thermal stability.
Line, L. G.↗
Longitude distribution of solar flares
Statistical tests of solar flares based on maximum likelihood method, discussing longitude distribution, rigid rotation, planetary effects, etc
Fung, P. C. W.↗
Inferences based on unreliable reports
Human inferences based on partially reliable reports, studying likelihood ratio estimates and probabilistic relations in nature
Fryback, D. G.↗
Improved navigation by combining VOR/DME information and air data
Navigational accuracy improvement by combining VOR/DME information with airspeed and heading data via maximum likelihood filter, using small airborne computer
Bobick, J. C.↗
A note on some efficient estimates of the noise variance for first-order Reed-Muller codes
Noise variance maximum likelihood estimate based on order statistics for first order Reed-Muller code transmission over zero-mean white Gaussian noise channel
Holmes, J. K.↗
Prediction of flow-induced failures of braided flexible hoses and bellows
Analytical techniques were developed to evaluate braided hoses and bellows for possibility of flow induced resonance. These techniques determine likelihood of high cycle fatigue failure when such resonance exists.
Sack, L. E.↗
Preprocessing of multispectral data and simulation of ERTS data channels to make computer terrain maps of a Yellowstone National Park test site
The possibility of improving the accuracy of terrain classification by preprocessing spectral data was investigated. Terrain maps were made using the following techniques: 1) preprocessing by scan angle function transformation, using the computer-selected best set of three channels; and 2) preprocessing by ratio transformation, using the specified ERTS data channels, simulated by fitting the spectral response of each of the 12 data channels to the ERTS channels by a set of weighting coefficients. By using a simple technique during printout, the maps were produced in color. The normalized scan angle function transformation resulted in the most accurate classification. The best ratio transformation for the Yellowstone Park data was the ratio of each channel to the sum of all channels. A supervised training program involving maximum likelihood decision for selecting the best spectrometer channels and similar techniques for digitizing the data of the analog magnetic tapes were used. Cloud shadows were recognized in addition to eight classes of terrain. Preprocessing of data resulted in more accurate maps, required fewer training areas (hence less preparation and computer time), and enabled much of the area formerly classified as shadow to be reclassified according to actual terrain type.
Smedes, H. W.↗
The application of signal detection theory to optics
The restoration of images focused on a photosensitive surface is treated from the standpoint of maximum likelihood estimation, taking into account the Poisson distributions of the observed data, which are the numbers of photoelectrons from various elements of the surface. A detector of an image focused on such a surface utilizes a certain linear combination of those numbers as the optimum detection statistic. Methods for calculating the false alarm and detection probabilities are proposed. It is shown that measuring noncommuting observables in an ideal quantum receiver cannot yield a lower Bayes cost than that attainable by a system measuring only commuting observables.
Helstrom, C. W.↗
The long winter model of Martian biology: A speculation
An estimated mean thickness of about 1 km of frost in the Martian north polar cap summer remnant, if vaporized, would yield about 1000 g/sq cm of atmosphere over the planet, higher global temperatures through the greenhouse effect, and a greatly increased likelihood of liquid water. Vaporization of such cap remnants may occur twice each equinoctial precession, and Martian organisms may now be in cryptobiotic repose awaiting the end of the long precessional winter. The Viking biology experiments can test this hypothesis.
Sagan, C.↗
Aerodynamic parameters of the Navion airplane extracted from flight
An iterative method, which is characterized as a maximum-likelihood minimum-variance technique, was used to extract the aerodynamic parameters of a Navion airplane from flight data. The purposes were to compare the results with parameters obtained from wind-tunnel tests and with results obtained by analog matching the same data, and to develop techniques for application of the parameter extraction program. Results from the study showed that the parameter-extraction program can produce aerodynamic parameters which will permit close estimation of the aircraft time histories used in the extraction process. The program determined an estimate of the standard deviations of the states and parameters. These estimates were used to indicate how well the calculated states fit the flight data and the confidence in the values of the estimated parameters. The study also showed that the values of the parameters were affected by the data and mathematical model used during the extraction process. Because of the lack of confidence in the parameters extracted by use of some of the sets of data, several parameters were estimated by other methods. By using a combination of methods, a set of parameters which gave a fit to the data was obtained.
Suit, W. T.↗
Recovery considerations for possible high inclination long duration earth orbital missions
Problem areas are discussed and various solutions proposed. One of the major recovery problems encountered with missions having higher orbital inclinations than previous missions is the greater likelihood of severe weather conditions in the landing zones, especially if landing zones are optimized for orbital coverage considerations. Restricting the reentry window and increasing in-orbit wait times can partially eliminate the weather problem, but the possibility of emergency landings at higher latitudes still exists. It can be expected that the increased confidence level in spacecraft reliability that will exist by the time the high-inclination missions are flown will reduce the probabilities of an emergency landing in an unfavorable recovery location to a very low level.
Obriant, T. E.↗
Analysis of simulated multispectral data from earth resources satellites
The validity of the applicability assumption was determined through the simulation of ERTS and Skylab data using available aircraft scanner systems. The research techniques compared aircraft multispectral scanner data obtained under nominal conditions at low altitudes. Maximum likelihood decision criteria algorithms implemented on a digital computer were used to classify training set data. Comparisons between percentages of correct classifications were made, along with implications as to the techniques of satellite analysis.
White, D. A.↗
Application of system safety to rail transit systems
Management emphasis on system safety in the rapid transit industry includes the granting and use of funds by the Federal Government according to systematic analysis of safety hazards in advance. Likelihood predictions that those hazards will be activated by exposure of the system to a system failure, a human error, external conditions, or combinations of these aspects determine alternatives to the assumption of risk and recommend corrections before the system is operational. Rigorous safety analyses are projected to assure operational safety for prolonged periods under varied maintenance conditions; these analysis encompass station accident possibilities as well as train-person collisions, car equipment and design, traffic control systems, and tunnel design problems.
Thomas DeW. Styles↗