Archivo: Usno-mc

Description: US Naval Observatory's (USNO) Master Clock Ensemble, Washington D.C., made up of a large number of Symmetricom 5071A cesium beam clocks (rack in background). This provides the time standard for the US military. The large black object in the foreground is a Symmetricom (formerly Sigma-Tau) MHM-2010 active hydrogen maser.
Title: Usno-mc
Credit: http://tycho.usno.navy.mil/gif/clockvaults.jpg
Author: US Naval Observatory
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License: Public domain
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