C
C     ATOMIC CLOCK TIME DIFFERENCES (BEFORE CENTERING)
C     (LOWER PLOT OF FIGURE 1 OF 2006 METROLOGIA PAPER SHOWS CENTERED SERIES
C     IN NANOSECONDS, I.E., AFTER MULTIPLICATION BY 1.0E9 = 1,000,000,000)
C
C     SOURCE: U. S. NAVAL OBSERVATORY (LARA SCHMIDT AND DEMETRIOS MATSAKIS)
C     DELTA T: 60 SECONDS
C     UNITS: SECONDS
C     SAMPLE SIZE: 4000
C