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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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Method of processing data from a spacecraft, where the carrier has a low signal-to-noise ratio and wide unpredictable frequency shifts, consists of analogue recording of the noisy signal along with a high-frequency tone that is used as a clock to trigger a digitizer.
When a transmitted word, consisting of a number of pulses, is detected and removed from the data stream, the space left by the removal is eliminated by a memory buffer. This eliminates the need for a clock synchronizer thereby removing instability problems.
Investigation of magnetic tape recorder-reproducer to accept data pulses at varying rates, record at constant packing density, and retrieve at rates synchronized to external clock
Feasibility of using ultrashort pulse laser ranging and independent clock radio interferometry distance measurement methods to test for existence of continental drift
Dual very low frequency transmission for time synchronization of ground station clocks
Redundant solid state digital clocks and code generators for reliable timing system
Development of portable atomic clock containing electromagnetically trapped ions
High speed, self-clocking single channel control and data link apparatus interfaces between two computers. This combined system reduces data errors.
Demodulation loop of automatic range-measuring system uses reference signal wave of locally generated pseudo-noise plus square wave of same period as the clock. Phase instabilities in IF amplifiers appear only as gain changes in the loop, and do not cause errors in range determination.
Electronic system /MIRACLE 2/ places frequency and gas flow rate of the respiratory process within a common frame of reference to render them comparable and compatible with ''real clock time.'' Numerous measurements are accomplished accurately on a strict one-minute half-minute, breath-by-breath, or other period basis.
Curve generator capable of producing precisely repeatable curve for any single-valued function of voltage versus time uses digital approach, implemented by means of clocked feedback shift register, large scale integrated circuit diode matrix comprising about 12,000 diodes, counter, and digital-to-analog converter.
High accuracy timing systems using satellite atomic clocks
Multiple-mission telemetry system operations with Mariner Mars 69 and Pioneers, and clock synchronization equipment
Relativistic red shift effect and its measurement by hydrogen maser clock
Pulsars pulse arrival time measured using cesium clock during weekly observations
Einstein theory of length contraction and time dilation relative to ether regarding slowness of clocks in motion
Digitizer accomplishes both N bit pulse code modulation /PCM/ and delta modulation, and provides modulation indicating variable signal gain and variable sidetone. Other features include - low package count, variable clock rate to optimize bandwidth, and easily expanded PCM output.
DSN research and technology support, including radiometric observations, pulsar observations, precision antenna gain measurement, and clock synchronization transmissions