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

MAGNET - STDI-STDI P.S.
Start: 21-May-2008
End: 09-Nov-2008
Blewitt, Geoff, Hammond, William C., Kreemer, Corne, 2010, MAGNET - STDI-STDI P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T51J97ZH