[IGSMAIL-6722] IGS time scale services restored

[Jake Griffiths - NOAA Federal]

Author: Analysis Center Coordinator

IGS product files (*.clk, *.clk_30s, *.cls) were replaced using the clock products
re-aligned to the restored IGS time scale provided by the IGS Clock Product Center
at the U.S. Naval Research Laboratory. The new clocks were also merged into the
corresponding *.sp3 files. The time spans for the effected files are:

product |
 series |  start                       stop
--------+----------------------------------------------------
    IGR |  1720_5 (Dec. 28, 2012)      1723_1 (Jan. 14, 2012)
    IGS |  1719_0 (Dec. 16, 2012)      1720_6 (Dec. 29, 2012)

The clock differences between all satellites and stations within one epoch will be
identical with the old clock products and therefore precise point positioning
results will not be affected by this change.

We expect the time scale services to resume normally starting with the IGR
products for 1723_2 to be released later today and IGS products for 1721 to be
released later in the week.

FYI,

Jake Griffiths (NOAA/NGS)