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Results for “Performance characteristics”

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 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Investigation of the performance characteristics of Doppler radar technique for aircraft collision hazard warning, phase 3

System studies, equipment simulation, hardware development and flight tests which were conducted during the development of aircraft collision hazard warning system are discussed. The system uses a cooperative, continuous wave Doppler radar principle with pseudo-random frequency modulation. The report presents a description of the system operation and deals at length with the use of pseudo-random coding techniques. In addition, the use of mathematical modeling and computer simulation to determine the alarm statistics and system saturation characteristics in terminal area traffic of variable density is discussed.

Source record↗
NASA NTRS1972

Quadrupole ion pump performance characteristics.

A new nonmagnetic ion pump is described that resembles a quadrupole ionization gauge. The dimensions are larger, and hyperbolically shaped electrodes replace the four rods. Pumping speeds (4-100 liters per sec) for different gases at various peak voltages (1000-3000 V) at corresponding frequencies (57-100 MHz) and at different pressures (10 microtorr to 1 nanotorr) are reported.

Schwarz, H.↗
NASA NTRS1973

Design and performance characteristics of the Vertical Temperature Profile Radiometer /VTPR/ for atmospheric temperature soundings.

Description of the design and operation of a radiometer which derives atmospheric temperature profiles on the basis of spectral measurements in eight optical filter channels. The radiometer achieves its eight-channel capability by sequentially viewing the eight optical filters mounted in a rotating filter wheel, with a single IR detector and electronic amplification channel processing the signal for all the filters. The advantages and disadvantages of this sequential approach as compared to eight 'parallel' radiometric channels are discussed. The proposed radiometer provides a relative calibration accuracy between seven out of the eight channels of better than 0.1% rms of the full dynamic range. The absolute accuracy achievable between in-flight calibrations of six minutes, or between two-hour calibrations using optical temperature correction factors, is better than an rms value of 0.15% of full scale. The radiometric correlation between the in-flight calibration source of the instrument and a reference standard blackbody is better than an rms value of 0.5% of full scale.

Falbel, G.↗
NASA NTRS1974

Advanced-power-reactor design concepts and performance characteristics

Five reactor cooling concepts which allow continued reactor operation following a single rupture of the coolant system are presented for application with the APR. These concepts incorporate convective cooling, double containment, or heat pipes to ensure operation after a coolant line rupture. Based on an evaluation of several control system concepts, a molybdenum clad, beryllium oxide sliding reflector located outside the pressure vessel is recommended.

Davison, H. W.↗
NASA NTRS1974

Implementation of an experimental program to investigate the performance characteristics of OMEGA navigation

A theoretical formulation of differential and composite OMEGA error is presented to establish hypotheses about the functional relationships between various parameters and OMEGA navigational errors. Computer software developed to provide for extensive statistical analysis of the phase data is described. Results from the regression analysis used to conduct parameter sensitivity studies on differential OMEGA error tend to validate the theoretically based hypothesis concerning the relationship between uncorrected differential OMEGA error and receiver separation range and azimuth. Limited results of measurement of receiver repeatability error and line of position measurement error are also presented.

Baxa, E. G., Jr.↗
NASA NTRS1975

Performance characteristics of the U.VA. superconducting wind tunnel balance

Initial operational characteristics of a wind tunnel electromagnetic balance utilizing superconducting coils are reported. Both dc and ac superconducting coils are used for balancing and measuring 3-component aerodynamic forces on simple models in Mach 3, room temperature flow. Liquid helium boil-off measurements corresponding to a wide range of operating conditions are presented together with results of systematic ac losses scaling experiments using various pancake coils wound with superconducting tape. This unique prototype facility is primarily for studying the practical feasibility of using superconducting magnetic suspension techniques for aerodynamic testing and accumulating the knowledge and expertise required for extrapolating these techniques to large-scale facilities.

Humphris, R. R.↗
NASA NTRS1974

Changes in the performance characteristics of a GaAs near infrared light emitting diode when exposed to various current and thermal stresses

The changes that occurred in the optical and electrical characteristics of a near infrared, GaAs light emitting diode, when operated under various levels and combinations of current and thermal stresses are discussed. A total of forty parts were operated for two thousand hours under eight different sets of dc current and ambient temperature conditions. Degradation in the radiant optical power of these devices was thirty-four percent when operated at their rated current and an ambient temperature of 298K (25 C). Derating the current and/or the thermal stress reduced the degradation of this parameter in approximately a linear manner. All degraded devices behaved similarly, exhibiting rapid nonlinear degradation followed by a gradual linear degradation and finally a period of stable operation. An attempt was made to correlate initial device condition to degradation during stress testing, but met with little success.

Thomas, E. F., Jr.↗