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

Greenland GNSS Network - SMM3-SummitCampGNSS__ P.S.
Start: 23-Aug-2017
End: 09-Oct-2022
UNAVCO Community, 2017, Greenland GNSS Network - SMM3-SummitCampGNSS__ P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T5FX7878