Hydrogen‐Maser Time and Frequency Standard at Agassiz Observatory

Abstract

The maser is a compact unit, of relatively low power consumption, specifically designed for field use and readily transportable. A precision 5-MHz crystal oscillator, phase-locked to the maser, provides all frequency and = time references for the VLBI receivers, recorde.s, and clocks. The maser was tuned against a rubidium standard by .a rapid flux-switching technique; maser frequency resettability was estimated to-be approximately t3 x 10-13 with an overall accuracy of approximately t1 x 10-12.Loran-C was continuously monitored during the VLBI experiments, and the results of the Loran-C -maser compar i s-)ns are included. ItHydrogen-maser time and frequency standard at Agassiz observatory

Analysis of the performance of hydrogen maser clocks at the Hartebeesthoek Radio Astronomy Observatory

“…Different timing reference standards are used to provide accurate time in geodetic and astronomical instrumentations such as Caesium, Rubidium, Oven Controlled Crystal Oscillators (OCXO) and atomic hydrogen maser (maser is an acronym for microwave amplification by stimulated emission of radiation) clocks. For the Very Long Baseline Interferometry (VLBI) applications, hydrogen maser clocks are recommended as frequency standards (Levine and Vessot 1970;Schuh and Böhm 2012). Other clocks are mainly used in Satellite Laser Ranging (SLR) or Lunar Laser Ranging (LLR) applications.…”