Search NASA⌕ Search

SEARCH · Search NASA

Results for “compensation”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
NASA NTRS1996

Frequency Stability of 1x10(sup -13) in a Compensated Sapphire Oscillator Operating Above 77K

We report on the design and test of a whispering gallery sapphire resonator for which the dominant (WGH (sub n11) ) microwave mode family shows frequency-stable, compensated operation for temperatures above 77 kelvin. The resonator makes possible a new ultra-stable oscillator (USO) capability that promises performance improvements over the best available crystal quartz oscillators in a compact cryogenic package.

Compensated Sapphire Oscillator Oscillators↗
NASA NTRS1996

Frequency Stability of 1X10(sup -13) in a compensated Saphirre Oscillator Operating Above 77K

We report on tests of a compensated saphirre oscillator (CS) which shows frequency-stable operation at temperatures above 77k.The frequency stability for this oscillator shows an apparent flicker floor of 7.5X10(sup -14) for measuring times between 3 and 10 seconds, and stability is better than 2X10(sup -13) for all measuring times between 10 and 100 seconds... Frequency sensitivities os the microwave sapphire resonator to temperature and temperature rate have been characterized, and a careful analysis of several aspects of the ac frequency-lock.

compensated saphirre oscillator frequency stabilit↗
NASA NTRS1996

Analysis of a Rain Compensation Algorithm for K/Ka-Band Communications

A rain compensation algorithm (RCA) has been developed for use in the ACTS Mobile Terminal (AMT) system. The basic goal of the RCA is to control the transmitted data rates (9.6, 4.8, or 2.4 kbps) in the forward and return links so that a 3 db link margin is maintained at the highest possible transmitted data rate.

rain compensation algorithm RCA ACTS Mobile Termin↗
NASA NTRS1995

Improved Performance of a Temperature Compensated LN2 Cooled Sapphire Oscillator

We report on improved stability in a whispering gallery sapphire resonator for which the dominant WGHn11 microwave mode family shows frequency-stable, compensated operation for temperatures above 77K. Several modifications during the past year have led to significant improvements in performance. Current tests with improved thermal stability provide Allan Deviation of frequency of 2.6 - 4 ? 10-13 for measurement times of 1#t#100 seconds. We project a frequency stability of 1014 for this resonator with stabilized housing temperature and with a mode Q of 107.!.

Temperature Compensated LN2 Cooled Sapphire Oscill↗
NASA NTRS1993

Probe Compensation Characterization in Cylindrical Near-Field Scanning

This paper presents a useful computer simulation methodology to properly characterize the role of probe compensation in cylindrical near-field scanning. The methodology is applied to a linear test array antenna and has been applied to other antenna configurations.

probe compensation near-field scanning waveguide r↗
NASA NTRS2019

Eddy Compensation Dampens Southern Ocean Sea Surface Temperature Response to Westerly Wind Trends

Anthropogenic influences have led to a strengthening and poleward shift of westerly winds over the Southern Ocean (SO), especially during austral summer. We use observations, an idealized eddy‐resolving ocean‐sea ice channel model, and a global coupled model to explore the SO response to a step‐change in westerly winds. Previous work hypothesized a two timescale response for sea surface temperature. Initially, Ekman transport cools the surface before sustained upwelling causes warming on decadal timescales. The fast response is robust across our models and the observations: we find Ekman‐driven cooling in the mixed layer, mixing‐driven warming below the mixed layer, and a small upwelling‐driven warming at the temperature inversion. The long‐term response is inaccessible from observations. Neither of our models shows a persistent upwelling anomaly, or long‐term, upwelling‐driven subsurface warming. Mesoscale eddies act to oppose the anomalous wind‐driven upwelling, through a process known as eddy compensation, thereby preventing long‐term warming.

Southern Annular Mode↗