During March 1988, detailed measurements of the physical properties and depth distributions of the snow cover on the sea ice in the Gulf of Bothnia were made as part of BEPERS-88 (Bothnian Experiment in Preparation for ERS-1). The observations included profiles of the density, crystal structure. salinity, temperature, and brine volume (at 1-2 cm depth intervals), and 1084 snow depth measurements. These data are presented along with discussions of the implications of the measured properties for the interpretation of SAR imagery, and the use of laser profilometry for remotely estimating ice surface roughnesses.