IGS Switch to IGS14

• The IGS intends to switch from IGS08/igs08.atx to IGS14/igs14.atx starting with products of GPS week 1934 (29 January 2017). 
• The IGS08/igs08.atx framework has been in effect since GPS week 1632 (17 April 2011).
• IGS08/igs08.ats was also used for the second IGS reprocessing campaign (repro2) back to 1994.

source: [IGSMAIL-7399] Upcoming switch to IGS14/igs14.atx: