This data set was acquired with a ship-based Navigation system during Nathaniel B. Palmer expedition NBP9803 conducted in 1998 (Chief Scientist: Dr. Martin Jeffries). These data files are of MGDS:Nav format and include Primary Navigation data and were processed after data collection. Data were acquired as part of the project(s): Sea Ice Motion,Deformation and Thickness Distribution in the Ross Sea combined with Ecological Studies of Sea-Ice Communities in the Ross Sea, and funding was provided by NSF grant(s): OPP96-14201 and OPP96-14844.