Voyager 1 48-s Triaxial Fluxgate Magnetometer (MAG) Magnetic Field Data Near and Beyond Termination Shock in ASCII Format

The  main science objectives for the VOYAGER interplanetary mission are as  \nfollows: \n- investigate the structure of the solar wind magnetic fields and plasma in the\ninner and outer heliosphere; \n- conduct long term study of heliospheric evolution during different phases of\nthe twenty-two year solar magnetic cycle and the eleven-year solar activity\ncycle;\n- study the long term solar modulation and determine the elemental and isotopic\nabundances of galactic cosmic ray particles in the heliosphere;\n- measure  radial gradients, spectra, and nuclear abundances of the anomalous\ncomponent of cosmic rays  from  acceleration at the solar wind termination\nshock; \n- investigate local particle acceleration in the interplanetary medium from\nsolar flare shocks and corotating interaction regions; \n- study propagation of solar energetic particles in the heliosphere.\nThe average magnetic field strength produced by the spacecraft at the location\nof the outboard magnetometer of the dual magnetometers system on V1 and V2 is\nabout 0.1 - 0.2 nT, comparable to the most probable magnetic field strength in\nthe inner heliosheath and significantly larger than the most probable magnetic\nfield strength in the distant supersonic solar wind. The spacecraft magnetic\nfield is a complex, time-dependent signal that must be removed from the measured\nmagnetic field signal in order to derive the ambient magnetic fields of the\nsolar wind and heliosheath. Corrections must also be made for spurious magnetic\nsignals and noise associated with the telemetry system, ground tracking systems,\nand other factors. Extracting the signal describing the solar wind and\nheliosheath from the many sources of uncertainty is a complex and partly\nsubjective process that requires understanding of the instrument and judgment\nbased on experience in dealing with the ever-changing extraneous signals. We\nestimate that for the V1 MAG data the 1-sigma the uncertainty the 48 sec\naverages for each of the components of the magnetic field  BR, BT, and BN is\ntypically +/- 0.02 nT; the uncertainty in magnitude F1 is typically +/- 0.03 nT.\nF1, BR, BT, and BN can differ from one another and they may vary with time, but\nthere is no practical way to determine these uncertainties more precisely at\npresent.\n\n        References \n        \n        Behannon, K.W., M.H. Acuna, L.F. Burlaga, R.P. Lepping, N.F. Ness, and F.M. Neubauer, \n        Magnetic-Field Experiment for Voyager-1 and Voyager-2, Space Science Reviews, 21 (3), 235-257, 1977. \n\n        Burlaga, L.F., Merged interaction regions and large-scale magnetic field fluctuations during 1991 - \n        Voyager-2 observations, J. Geophys. Res., 99 (A10), 19341-19350, 1994. \n\n        Burlaga, L.F., N.F. Ness, Y.-M. Wang, and N.R. Sheeley Jr., Heliospheric magnetic field strength and \n        polarity from 1 to 81 AU during the ascending phase of solar cycle 23, J. Geophys. Res., 107 (A11), 1410, 2002. \n\n        Ness, N., K.W. Behannon, R. Lepping, and K.H. Schatten, J. Geophys. Res., , 76, 3564, 1971.\n        \n

Tags: magneticfield
Organization: National Aeronautics and Space Administration