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

HOPRnet GPS Network - RIFC-Rifnihnjukur
Start: 23-Oct-2014
End: 17-Oct-2019
Grapenthin, Ronni, 2016, HOPRnet GPS Network - RIFC-Rifnihnjukur, UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/QSTY-N037