Voyager 1 48-s Triaxial Fluxgate Magnetometer (MAG) Magnetic Field Data in ASCII Format

The average magnetic field strength produced by the spacecraft at the location of the outboard magnetometer, of the dual magnetometers system on V1, varies between 0.1 and 0.2 nT, comparable to the most probable magnetic field strength in the inner heliosheath and significantly larger than the most probable magnetic field strength in the distant supersonic solar wind. The spacecraft magnetic field is a complex, time-dependent signal that must be removed from the measured magnetic field signal in order to derive the ambient magnetic fields of the solar wind and heliosheath. Corrections must also be made for spurious magnetic signals and noise associated with the telemetry system, ground tracking systems, and other factors. Extracting the signal describing the solar wind and heliosheath from the many sources of uncertainty is a complex and partly subjective process that requires understanding of the instrument and judgment based on experience in dealing with the ever-changing extraneous signals. We estimate that the 1-sigma uncertainty in the 48 sec averages in the components of the magnetic field is typically +/- 0.02 nT. The uncertainties in F1, BR, BT, and BN can differ from one another and they may vary with time, but there is no practical way to determine these uncertainties more precisely at present. This descriptor, and the data access path identified below, are specific to 48s Voyager 1 MAG data taken when the spacecraft was in the vicinity of, and beyond, the heliospheric termination shock. References Behannon, K.W., M.H. Acuna, L.F. Burlaga, R.P. Lepping, N.F. Ness, and F.M. Neubauer, Magnetic-Field Experiment for Voyager-1 and Voyager-2, Space Science Reviews, 21 (3), 235-257, 1977. Burlaga, L.F., Merged interaction regions and large-scale magnetic field fluctuations during 1991 - Voyager-2 observations, J. Geophys. Res., 99 (A10), 19341-19350, 1994. Burlaga, L.F., N.F. Ness, Y.-M. Wang, and N.R. Sheeley Jr., Heliospheric magnetic field strength and polarity from 1 to 81 AU during the ascending phase of solar cycle 23, J. Geophys. Res., 107 (A11), 1410, 2002. Ness, N., K.W. Behannon, R. Lepping, and K.H. Schatten, J. Geophys. Res., , 76, 3564, 1971.