A Correlational Analysis of the Effects of Changing Environmental Conditions on the NR Atomic Hydrogen Maser

Abstract

An extensive statistical analysis has been undertaken to determine if a correlation exists between changes in an NR atomic hydrogen maser's frequency offset and changes in environmental conditions. Data have been acquired over the past 20 months by recording the frequency offset of three NR atomic hydrogen masers along with the relative and absolute humidity, barometric pressure, and ambient temperature of the laboratory in which the masers are maintained. Correlational analyses have been performed comparing barometric pressure, humidity, and temperature with maser frequency offset as functions of time for periods ranging from 5.5 to 17 days. Semi partial correlation coefficients as large as -0.9 have been found between barometric pressure and maser frequency offset for data covering period as long as a week. Maser frequency offset and barometric pressure were consistently found to change simultaneously&. The correlation between humidity and frequency offset@et is less predictable, and the resulting semi partial correlation coefficients were usually small when compared with those derived from the relationship between pressure and frequency offset. The time delay between changes in humidity and correlated changes in maser frequency offset was found to vary extensively with no predictable pattern. Analysis of temperature data indicates that, in the most current design, temperature does not significantly affect maser frequency offset in the laboratory environment.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1991
Accession Number
ADA494709

Entities

People

  • J. J. Suter
  • R. A. Dragonette

Organizations

  • Johns Hopkins University

Tags

Communities of Interest

  • Sensors

DTIC Thesaurus Topics

  • Atomic Beam Masers
  • Barometric Pressure
  • Cavity Resonators
  • Climate Change
  • Coefficients
  • Crystal Oscillators
  • Data Acquisition
  • Data Sets
  • Dew Point
  • Elements
  • Frequency
  • Humidity
  • Hydrogen
  • Masers
  • Physics Laboratories
  • Resonant Frequency
  • Statistical Analysis

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  • Organizational Psychology.
  • Positioning, Navigation, and Timing (PNT) Technology.