The following information obtained from UNAVCO's online DOI system:
(https://www.unavco.org/data/doi/search/search.html)

PBO GPS Network - GOGA-Godfrey___GA2006 P.S.
Start: 13-Apr-2006
End: 29-May-2013
UNAVCO Community, 2007, PBO GPS Network - GOGA-Godfrey___GA2006 P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T57S7KRG