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

Hawaii GPS Network - MLPM-Mauna Loa P.S.
Start: 30-May-1999
End: 17-Jul-2005
Segall, Paul, Miklius, Asta, 1999, Hawaii GPS Network - MLPM-Mauna Loa P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T5WM1BGW