This data set includes data from the Low Field Magnetometer (LFM) during the inbound Neptune encounter beginning in the solar wind and continuing until the first magnetopause crossing. The magnetometer are given in Heliographic coordinates and the data have been averaged from the resample 9.6 second sample rate to a 48.0 second rate. The dataset consists of the following columns: 1) ctime (decimal seconds since 1966-01-01T00:00:00.000), 2) pdstime (ISO standard time format), 3-5) spacecraft clock (m65536,m60,fds-line), 6) magnetometer id (1 = LFM, 2 = HFM), 7), Br (radial component), 8) Bt (tangential component), 9) Bn (normal component), 10) Bmag (magnitude of the average components), 11) avg_Bmag (average of the magnitude of the raw components), 12) Lambda (longitude = tan^-1(Bt/Br)), 13) Delta (latitude = sin^-1(Bn/avg_Bmag) ), 14-16) rms vector (pythagorean root mean square deviation of the component averages), 17) npts (number of points in average), 18) flag a character string which indicates software or s/c hardware intervention which reduces confidence in the data (NULL flags represent 'good' data).