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Results for “error rate”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 649 records · Page 36
All sourcesNASA NTRSDOE OSTI
NASA NTRS1966

Gemini orbital tracking.

Simulation testing pilot performance in orbiting Gemini spacecraft based on tracking rate errors and fuel consumption

ASTRONAUT PERFORMANCE↗
NASA NTRS1970

Digital demodulation with data subcarrier tracking

Digital demodulator is based on early-late bit timing scheme coupled with Costas data tracking loop. System is successful in enhancement of weak signals from space where atmospheric and other interference media cause bit error rate to reach excessive level.

Sanger, D. K.↗
NASA NTRS1971

Nonparametric Bayer-risk estimation

Nonparametric Bayes risk estimation for measurement classification, using nearest neighbor error rate and Parzen probability density function estimators

Fralick, S. C.↗
NASA NTRS1971

Investigation of techniques for improving Saturn 5 RF tracking and ranging systems

Results of theoretical analyses of 12 problems are presented and comparisons of theoretical and experimental results are given. The investigations covered were: (1) techniques for improving the Saturn radar altimeter, (2) performance of the phase lock loop of the offset Doppler transponder, (3) signal processing equipment design for an orbital altitude radar return experiment, (4) spectral studies of signals present in the command and communication system (CCS) up-link transmitter, (5) intermodulation in the CCS down-link data demodulators, (6) error rate performance of the CCS transponder command demodulator, (7) flame attenuation effects on telemetry transmissions during Saturn launches, (8) design of a digital television system which converts a standard monochrome picture to a slow-scan picture, (9) methods of obtaining an additional CCS 72-kilobit/sec telemetry channel, (10) computation of the CCS S-band down-link spectra, (11) modeling of portions of the communications systems, and (12) modeling of a telemetry transmitter.

Walsh, J. R., Jr.↗
NASA NTRS1972

A study of FM threshold extension techniques

The characteristics of three postdetection threshold extension techniques are evaluated with respect to the ability of such techniques to improve the performance of a phase lock loop demodulator. These techniques include impulse-noise elimination, signal correlation for the detection of impulse noise, and delta modulation signal processing. Experimental results from signal to noise ratio data and bit error rate data indicate that a 2- to 3-decibel threshold extension is readily achievable by using the various techniques. This threshold improvement is in addition to the threshold extension that is usually achieved through the use of a phase lock loop demodulator.

Arndt, G. D.↗
NASA NTRS1973

Balloon atmospheric propagation experiment measurements

High altitude balloon measurements on laser beam fading during propagation through turbulent atmosphere show that a correlation between fading strength and stellar scintillation magnitudes exists. Graphs for stellar scintillation as a function of receiver aperture are used to predict fading bit error rates for neodymium-yag laser communication system.

Minott, P. O.↗
NASA NTRS1972

The ERTS wideband image communication system.

The ERTS payload includes a three camera return beam vidicon (RBV) television system and a four channel multispectral scanner system (MSS). The communications system described includes spacecraft wideband equipment plus unique payload processing equipment located at three NASA tracking stations. The RBV information, transmitted as analog FM with a baseband response of dc to 3.2 MHz, is telemetered, processed and recorded on a wideband video recorder. The MSS data, consisting of 24 analog sensor outputs, is digitized and encoded as 15 megabit per second PCM. The MSS data is then transmitted as analog FM, demultiplexed, and recorded on a 25 channel recorder. It is shown that bit error rate is an excellent indicator of MSS link performance while signal-to-noise ratio and distortion vs frequency adequately define RBV link performance.

Pandelides, J.↗
NASA NTRS1972

Coded communication link for an advanced manned spacecraft.

An analysis, in terms of key design parameters, is presented of a digital link for bidirectional communication between an advanced manned spacecraft, such as the space shuttle, and a ground terminal by means of a synchronous communication relay satellite. Performance of both ground to manned spacecraft and return links are compared with and without coding. A breadboard terminal for simulating the two-way link is described. Results of error rate tests are discussed.

Gould, L. M.↗
NASA NTRS1974

Evaluation of three coding schemes designed for improved data communication

Three coding schemes designed for improved data communication are evaluated. Four block codes are evaluated relative to a quality function, which is a function of both the amount of data rejected and the error rate. The Viterbi maximum likelihood decoding algorithm as a decoding procedure is reviewed. This evaluation is obtained by simulating the system on a digital computer. Short constraint length rate 1/2 quick-look codes are studied, and their performance is compared to general nonsystematic codes.

Snelsire, R. W.↗