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CASSINI MAGNETOMETER RAW DATA V1.0

This data set contains magnetic-field data acquired during the cruise and tour phases of the Cassini mission to Saturn. The data set begins with data collected on 16 August (day 228), 1999 and ends on 17 November (day 321), 2005 when the instrument failed. On 16 August, 1999 two days before the spacecraft commenced Earth swingby, the magnetometer boom was unfurled into its extended position; a configuration it maintained for the remainder of the mission. Magnetic-field data acquired prior to boom deployment are limited and are significantly affected by spacecraft noise. These data are of no scientific value and, consequently, do not form part of this data set.

IMP-8 Weimer Propagated 60 s Resolution Tri-axial Fluxgate Magnetometer in GSE Coordinates

IMP-8 Weimer propagated solar wind data and linearly interpolated to have the measurements on the minute at 60 s resolution tri-axial fluxgate magnetometer data in GSE coordinates. This data set consists of propagated solar wind data that has first been propagated to a position just outside of the nominal bow shock (about 17, 0, 0 Re) and then linearly interpolated to 1 min resolution using the interp1.m function in MATLAB. The input data for this data set is a 1 min resolution processed solar wind data constructed by Dr. J.M. Weygand. The method of propagation is similar to the minimum variance technique and is outlined in Dan Weimer et al. [2003; 2004]. The basic method is to find the minimum variance direction of the magnetic field in the plane orthogonal to the mean magnetic field direction. This minimum variance direction is then dotted with the difference between final position vector minus the original position vector and the quantity is divided by the minimum variance dotted with the solar wind velocity vector, which gives the propagation time. This method does not work well for shocks and minimum variance directions with tilts greater than 70 degrees of the sun-earth line. This data set was originally constructed by Dr. J.M. Weygand for Prof. R.L. McPherron, who was the principle investigator of two National Science Foundation studies: GEM Grant ATM 02-1798 and a Space Weather Grant ATM 02-08501. These data were primarily used in superposed epoch studies. References: Weimer, D. R. (2004), Correction to ‘‘Predicting interplanetary magnetic field (IMF) propagation delay times using the minimum variance technique,’’ J. Geophys. Res., 109, A12104, doi:10.1029/2004JA010691. Weimer, D.R., D.M. Ober, N.C. Maynard, M.R. Collier, D.J. McComas, N.F. Ness, C. W. Smith, and J. Watermann (2003), Predicting interplanetary magnetic field (IMF) propagation delay times using the minimum variance technique, J. Geophys. Res., 108, 1026, doi:10.1029/2002JA009405.

ISEE 2 Linearly Interpolated 60 s Resolution Tri-axial Fluxgate Magnetometer in GSM Coordinates

ISEE-2 linearly interpolated to have the measurements on the minute at 60 s resolution tri-axial fluxgate magnetometer data in GSM coordinates. This data set consists of processed solar wind data that has been linearly interpolated to 1 min resolution at the position of the spacecraft using the interp1.m function in MATLAB. This data set was originally constructed by Dr. J.M. Weygand for Prof. R.L. McPherron, who was the principle investigator of two National Science Foundation studies: GEM Grant ATM 02-1798 and a Space Weather Grant ATM 02-08501. These data were primarily used in superposed epoch studies and cross correlation studies on solar wind.

JUNO SS FLUXGATE MAGNETOMETER CALIBRATED DATA V1.0

Abstract ======== This data set consists of the Juno FGM calibrated cruise observations. The FGM sensor block uses two miniature ring-core fluxgate sensors to measure the magnetic field in three components of the vector field. There are multiple FGM data products to accomodate different coordinate systems.

VOYAGER 2 SATURN MAGNETOMETER RESAMPLED DATA 1.92 SEC

This data set includes Voyager 2 Saturn encounter magnetometer data that have been resampled at a 1.92 second sample rate. The data set is composed of 6 columns: 1) ctime - this column contains the data acquisition time. The time is always output in the ISO standard spacecraft event time format (yyyy-mm-dd-Thh:mm:ss.sss) but is stored internally in Cline time which is measured in seconds after 00:00:00.000 Jan 01, 1966, 2) br - this column contains the radial component of the magnetic field, 3) bphi - this column contains the phi component of the magnetic field, 4) btheta - this column contains the theta component of the magnetic field, 5) bmag - this column contains the magnitude of the magnetic field, 6) flag - a flag value that indicates either software error or spacecraft hardware interference reduced confidence in this record (flag value of 1 is bad , 0 is good or unchecked). All magnetic field observations are measured in nanoTeslas. The coordinate system for this dataset is Minus Saturn Longitude System (-SLS). All of the magnetic field data are calibrated (see the instrument calibration description for more details). The SLS coordinate system is defined in Desch and Kaiser, 1981 and the reference documents for this dataset are: Ness et al, 1982 Acuna,Connerney,and Ness, 1983 Connerney,Acuna,and Ness, 1983 Behannon,Lepping,and Ness, 1983

ISEE 1 Weimer Propagated 60 s Resolution Tri-axial Fluxgate Magnetometer in GSE Coordinates

ISEE-1 Weimer propagated solar wind data and linearly interpolated to have the measurements on the minute at 60 s resolution tri-axial fluxgate magnetometer data in GSE coordinates. This data set consists of propagated solar wind data that has first been propagated to a position just outside of the nominal bow shock (about 17, 0, 0 Re) and then linearly interpolated to 1 min resolution using the interp1.m function in MATLAB. The input data for this data set is a 1 min resolution processed solar wind data constructed by Dr. J.M. Weygand. The method of propagation is similar to the minimum variance technique and is outlined in Dan Weimer et al. [2003; 2004]. The basic method is to find the minimum variance direction of the magnetic field in the plane orthogonal to the mean magnetic field direction. This minimum variance direction is then dotted with the difference between final position vector minus the original position vector and the quantity is divided by the minimum variance dotted with the solar wind velocity vector, which gives the propagation time. This method does not work well for shocks and minimum variance directions with tilts greater than 70 degrees of the sun-earth line. This data set was originally constructed by Dr. J.M. Weygand for Prof. R.L. McPherron, who was the principle investigator of two National Science Foundation studies: GEM Grant ATM 02-1798 and a Space Weather Grant ATM 02-08501. These data were primarily used in superposed epoch studies. References: Weimer, D. R. (2004), Correction to ‘‘Predicting interplanetary magnetic field (IMF) propagation delay times using the minimum variance technique,’’ J. Geophys. Res., 109, A12104, doi:10.1029/2004JA010691. Weimer, D.R., D.M. Ober, N.C. Maynard, M.R. Collier, D.J. McComas, N.F. Ness, C. W. Smith, and J. Watermann (2003), Predicting interplanetary magnetic field (IMF) propagation delay times using the minimum variance technique, J. Geophys. Res., 108, 1026, doi:10.1029/2002JA009405.

GALILEO ORBITER JUPITER RAW MAGNETOMETER DATA V1.0

This data set contains raw magnetic field data acquired by the Galileo Orbiter magnetometer at Jupiter. The data set covers the time period from 1995-11-06T00:21:30 UT (Jupiter approach) until the end of mission (March 2003). The raw magnetometer data set includes various forms of data: recorded high time resolution, real-time survey (RTS), optimal averager (opt/avg), snapshot, and the calibration parameters required to generate processed data products. In addition corrected rotor angles and spacecraft relative clock and cone angles are provided to simplify future calibration and reprocessing of the data.

MMS 4 Digital Signal Processor (DSP) Search Coil Magnetometer (SCM), Magnetic Field Power Spectral Density, Level 2 (L2), Fast Mode, 2 s Data

The MMS magnetic field power spectral density (BPSD) is computed onboard by the Digital Signal Processor (DSP). The fast Fourier transform (FFT) calculation is performed on a digitized version of analog signals from the Search Coil Magnetometer (SCM) in the SCM123 coordinate system, see SCM data product guide for details, https://lasp.colorado.edu/mms/sdc/public/datasets/fields/. This data product is computed in space from individual components that are not synchronized to the 1 second pulse. Therefore, the timing between channels can be inaccurate by a fraction of a second. The samples times are interval start times taken from the x component. The spectra are calculated via a 1024-point FFT algorithm on piecewise continuous sets of waveform data. Nine signals can be processed simultaneously. Six of the twelve DC-coupled E, DC-coupled V, or SCM signals (16384 samples/s) are selected for spectral processing at 100% duty cycle. In addition, the three AC-coupled signals (262,144 kS/s) each can be processed at 6.25% duty cycle. Each of the nine signals has 16, 1024-point FFT operations every second; the field-programmable gate array (FPGA) performs 144 FFTs per second. The FFT is performed by an arithmetic logic unit (ALU), which is controlled by a state machine. Both are hard-coded into the FPGA. The operation starts by applying a 1024-point Hanning window onto a waveform. Next, an FFT is implemented. The FFT is broken into a series of "butterfly" operations performed by the ALU. The result has real and imaginary data. Power spectra are calculated by taking the sum of squares of real and imaginary values (the ALU includes a multiplier), which produces a power spectrum with 512 frequency bins. The frequency bins are then combined to give pseudo-logarithmic frequency spacing (del f)/f. The spectra are reduced to 88 frequency bins with (del f)/f between 6% and 12% when possible. Narrow-band emissions can be fit to an accuracy of (del f)/f ~3%, allowing for an accurate determination of plasma density. The spectra can be averaged in time. The fastest reporting rate of any signal is 16 spectra per second. Reporting rates can be as slow a one spectra every 16 s (averaging 256 spectra). The DSP and SCM instrument papers can be found at https://link.springer.com/article/10.1007/s11214-014-0115-x and https://link.springer.com/article/10.1007/s11214-014-0096-9, respectively. The DSP and SCM data product guides can be found at https://lasp.colorado.edu/mms/sdc/public/datasets/fields/.

THEMIS-A: Probe Electric Field Instrument and Search Coil Magnetometer Instrument, Digital Fields Board - digitally computed Filter Bank spectra and E12 peak and average in HF band (FBK).

The Filter Bank is part of the Digital fields board and provides band-pass filtering for EFI and SCM spectra as well as E12HF peak and average value calculations. The Filter Bank provides band-pass filtering for less computationally and power intensive spectra than the FFT would provide. The process is as follows: Signals are fed to the Filter Bank via a low-pass FIR filter with a cut-off frequency half that of the original signal maximum. The output is passed to the band-pass filters, is differenced from the original signal, then absolute value of the data is taken and averaged. The output from the low-pass filter is also sent to a second FIR filter with 2:1 decimation. This output is then fed back through the system. The process runs through 12 cascades for input at 8,192 samples/s and 13 for input at 16,384 samples/sec (EAC input only), reducing the signal and computing power by a factor 2 at each cascade. At each cascade a set of data is produced at a sampling frequency of 2^n from 2 Hz to the initial sampling frequency (frequency characteristics for each step are shown below in Table 1). The average from the Filter Bank is compressed to 8 bits with a pseudo-logarithmic encoder. The data is stored in sets of six frequency bins at 2.689 kHz, 572 Hz, 144.2 Hz, 36.2 Hz, 9.05 Hz, and 2.26 Hz. The average of the coupled E12HF signal and it's peak value are recorded over 62.5 ms windows (i.e. a 16 Hz sampling rate). Accumulation of values from signal 31.25 ms windows is performed externally. The analog signals fed into the FBK are E12DC and SCM1. Sensor and electronics design provided by UCB (J. W. Bonnell, F. S. Mozer), Digital Fields Board provided by LASP (R. Ergun), Search coil data provided by CETP (A. Roux). Table 1: Frequency Properties. Cascade Frequency content of Input Signal Low-pass Filter Cutoff Frequency Freuency Content of Low-pass Output Signal Filter Bank Frequency Band 0* 0 - 8 kHz 4 kHz 0 - 4 kHz 4 - 8 kHz 1 0 - 4 kHz 2 kHz 0 - 2 kHz 2 - 4 kHz 2 0 - 2 kHz 1 kHz 0 - 1 kHz 1 - 2 kHz 3 0 - 1 kHz 512 Hz 0 - 512 Hz 512 Hz - 1 kHz 4 0 - 512 Hz 256 Hz 0 - 256 Hz 256 - 512 Hz 5 0 - 256 Hz 128 Hz 0 - 128 Hz 128 - 256 Hz 6 0 - 128 Hz 64 Hz 0 - 64 Hz 64 - 128 Hz 7 0 - 64 Hz 32 Hz 0 - 32 Hz 32 - 64 Hz 8 0 - 32 Hz 16 Hz 0 - 16 Hz 16 - 32 Hz 9 0 - 16 Hz 8 Hz 0 - 8 Hz 8 - 16 Hz 10 0 - 8 Hz 4 Hz 0 - 4 Hz 4 - 8 Hz 11 0 - 4 Hz 2 Hz 0 - 2 Hz 2 - 4 Hz 12 0 - 2 Hz 1 Hz 0 - 1 Hz 1 - 2 Hz *Only available for 16,384 Hz sampling.

STEREO-A In-Situ Measurements of Particles and CME Transients (IMPACT) Fluxgate Magnetometer (MAG) Magnetic Field Vectors, in Spacecraft (SC) Coordinates

STEREO Ahead In-situ Measurements of Particles and CME Transients, IMPACT, Magnetometer Instrument, MAG, Magnetic Field Vectors, Level 1 Data

Voyager 2 48-s Triaxial Fluxgate Magnetometer (MAG) Magnetic Field Data Near and Beyond Termination Shock in CDF Format

The main science objectives for the Voyager Interplanetary Mission, VIM, are as follows: - investigate the structure of the solar wind magnetic fields and plasma in the inner and outer heliosphere; - conduct long term study of heliospheric evolution during different phases of the 22-year solar magnetic cycle and the 11-year solar activity cycle; - study the long term solar modulation and determine the elemental and isotopic abundances of galactic cosmic ray particles in the heliosphere; - measure radial gradients, spectra, and nuclear abundances of the anomalous component of cosmic rays from acceleration at the solar wind termination shock; - investigate local particle acceleration in the interplanetary medium from solar flare shocks and corotating interaction regions; - study propagation of solar energetic particles in the heliosphere. The average magnetic field strength produced by the spacecraft at the location of the outboard magnetometer of the dual magnetometers system on Voyager 1 and Voyager 2 is about 0.1-0.2 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 judgement based on experience in dealing with the ever-changing extraneous signals. We estimate that for the Voyager magnetic field data the 1-sigma the uncertainty of the 48-s averages for each of the components of the magnetic field BR, BT, and BN is typically +/- 0.02 nT; the uncertainty in magnitude F1 is typically +/- 0.03 nT. 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. References: D.B. Berdichevsky, Voyager Mission, Detailed processing of weak magnetic fields; I - Constraints to the uncertainties of the calibrated magnetic field signal in the Voyager missions, 2009; https://vgrmag.gsfc.nasa.gov/Berdichevsky-VOY_sensor_opu090518.pdf 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., Spacecraft studies of the interplanetary magnetic field, 76, 3564, 1971.

GIOTTO MAGNETOMETER 8 SECOND DATA V1.0

The main objective of the Giotto Magnetometer Experiment is the investigation of the interaction between Comet Halley and the solar wind at a distance of 0.9 AU from the Sun, to within 500 km of the cometary nucleus. A second objective is the study of the interplanetary magnetic field. The instrumentation consists of a triaxial and a separate biaxial system of fluxgate sensors of the ring-core type, the associated analogue electronics and a digital processor. The measuring ranges of +/- 16 nT, +/- 64 nT, etc., up to +/- 65536 nT are digitis- ed by a 12-bit analogue-to-digital converter, allowing a sampling rate of 28.24 vectors per second at encounter. Memory modes allow the bridging of gaps in telemetry coverage of up to ten days. The total mass of the instrument is 1360 g and its power consumption 820 mW.

IMP-8 Linearly Interpolated 60 s Resolution Tri-axial Fluxgate Magnetometer in GSE Coordinates

IMP-8 linearly interpolated to have the measurements on the minute at 60 s resolution tri-axial fluxgate magnetometer data in GSE coordinates. This data set consists of processed solar wind data that has been linearly interpolated to 1 min resolution at the position of the spacecraft using the interp1.m function in MATLAB. This data set was originally constructed by Dr. J.M. Weygand for Prof. R.L. McPherron, who was the principle investigator of two National Science Foundation studies: GEM Grant ATM 02-1798 and a Space Weather Grant ATM 02-08501. These data were primarily used in superposed epoch studies and cross correlation studies on solar wind.

Voyager 1 1.92-s Averaged Triaxial Fluxgate Magnetometer (MAG) Interplanetary Magnetic Field in CDF Format

This data set includes the Voyager spacecraft number (1 or 2), the date-time in decimal year (90.00000 is day 1 of 1990), the magnetic field strength, F1, computed from high-resolution magnitudes, the elevation and azimuth angles in heliographic (RTN) coordinates, and the magnetic field strength, F2, computed from 1-hr averages of the components. The vector components of B can be computed from F2 and the two angles. The elevation angle is the latitude angle above or below the solar equatorial plane, and the azimuth angle is in the direction orbital motion around the Sun from the projection of the Sun-to-spacecraft axis into the solar equatorial plane. The Voyager MAG experiment and coordinates are further described in the following publication: 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 Sci. Rev., 21 (3), 235-257, 1977. At the time of experiment proposal, it was expected that the required accuracy of the measurements would be 0.1 nT, determined by the combined noise of the sensors and the spacecraft field. The spacecraft magnetic field at the outboard magnetic field sensor, referred to as the primary unit, was expected to be 0.2 nT and highly variable, consistent with current estimates. Hence, the dual magnetometer design (Ness et al., 1971, 1973; Behannon et al., 1977). At distances > 40 AU, the heliospheric magnetic fields are generally much weaker than 0.4 nT; the average magnetic field strength near 40 AU and 85 AU is about 0.15 nT and 0.05 nT, respectively. The use of roll calibrations lasting about 6 hours permits determination of the effective zero levels for the two independent magnetic axes that are perpendicular to the roll axis, which is nearly parallel to the radius vector to the Sun, at intervals of about 3 months. There is no roll calibration for the third magnetic axis. Comparison of the two derived magnetic vectors from the two magnetometers permits validation of the primary magnetometer data with an accuracy of 0.02 to 0.05 nT. A discussion of the uncertainties that must be considered when using these data is given in the Appendix of Burlaga et al. (1994) and in Appendix A of Burlaga et al. (2002). 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. Ness et al., 1973. Coordinate Systems: Interplanetary magnetic field studies make use of two important coordinate systems, the Heliographic Inertial (HGI) coordinate system and the Heliographic (HG) coordinate system. The HGI coordinate system is used to define the spacecraft's position. The HGI system is defined with its origin at the Sun. There are three orthogonal axes, X(HGI), Y(HGI), and Z(HGI). The Z(HGI) axis points northward along the Sun's spin axis. The X(HGI)-Y(HGI) plane lays in the solar equatorial plane. The intersection of the solar equatorial plane with the ecliptic plane defines a line, the longitude of the ascending node, which is taken to be the X(HGI) axis. The X(HGI) axis drifts slowly with time, approximately one degree per 72 years. The magnetic field orientation is defined in relation to the spacecraft. Drawing a line from the Sun's center (HGI origin) to the spacecraft defines the X axis of the HG coordinate system. The HG coordinate system is defined with its origin centered at the spacecraft. Three orthogonal axes are defined, X(HG), Y(HG), and Z(HG). The X(HG) axis points radially away from the Sun and the Y(HG) axis is parallel to the solar equatorial plane and therefore parallel to the X(HGI)-Y(HGI) plane as well. The Z(HG) axis is chosen to complete the orthonormal triad. An excellent reference guide with diagrams explaining the HGI and HG systems may be found in L.F. Burlaga, MHD Processes in the Outer Heliosphere, Space Sci. Rev., 39, 255-316, 1984.

ISEE 2 magnetometer 4-sec data

4-sec vector magnetic field values recorded by the ESA ISEE-2 satellite, in spacecraft coordinates (close to GSE).

ISEE 1 Weimer Propagated 60 s Resolution Tri-axial Fluxgate Magnetometer in GSM Coordinates

ISEE-1 Weimer propagated solar wind data and linearly interpolated to have the measurements on the minute at 60 s resolution tri-axial fluxgate magnetometer data in GSM coordinates. This data set consists of propagated solar wind data that has first been propagated to a position just outside of the nominal bow shock (about 17, 0, 0 Re) and then linearly interpolated to 1 min resolution using the interp1.m function in MATLAB. The input data for this data set is a 1 min resolution processed solar wind data constructed by Dr. J.M. Weygand. The method of propagation is similar to the minimum variance technique and is outlined in Dan Weimer et al. [2003; 2004]. The basic method is to find the minimum variance direction of the magnetic field in the plane orthogonal to the mean magnetic field direction. This minimum variance direction is then dotted with the difference between final position vector minus the original position vector and the quantity is divided by the minimum variance dotted with the solar wind velocity vector, which gives the propagation time. This method does not work well for shocks and minimum variance directions with tilts greater than 70 degrees of the sun-earth line. This data set was originally constructed by Dr. J.M. Weygand for Prof. R.L. McPherron, who was the principle investigator of two National Science Foundation studies: GEM Grant ATM 02-1798 and a Space Weather Grant ATM 02-08501. These data were primarily used in superposed epoch studies References: Weimer, D. R. (2004), Correction to ‘‘Predicting interplanetary magnetic field (IMF) propagation delay times using the minimum variance technique,’’ J. Geophys. Res., 109, A12104, doi:10.1029/2004JA010691. Weimer, D.R., D.M. Ober, N.C. Maynard, M.R. Collier, D.J. McComas, N.F. Ness, C. W. Smith, and J. Watermann (2003), Predicting interplanetary magnetic field (IMF) propagation delay times using the minimum variance technique, J. Geophys. Res., 108, 1026, doi:10.1029/2002JA009405.

Helios 2 E3 Magnetometer (Ness et al.) 6-sec Data

Task of the HELIOS mission was the exploration of the inner heliosphere, inside the Earth's orbit to 0.3 AU. The Rome-GSFC magnetic field experiment has been a joint venture of an italian group (University of Rome and CNR/Istituto Fisica Spazio Interplanetario, Frascati) and an american group of NASA/Goddard Space Fligth Center, under the responsibility of F. Mariani and N.F.Ness, respectively. A description of the experiment can be found in the NASA-GSFC report X-692-75-112 (1975), by C. Scearce et al. The instrument is a dual configuration of two tri-axial fluxgate magnetometers operating at four different sensitivities (from 0.84 to 0.03 nT). The time resolution, depending the operation mode, telemetry format, and bit rate, for most cases varied from 0.07 to 1.5 seconds. The present data set contains six-second averages of the magnetic field elements in solar-ecliptic (SE) spacecraft-centered coordinates. Data are stored in files on a daily basis. File names are hNYYDDD.asc, with N the Helios number (1 or 2), YY the year (last two digits), and DDD the day of year (1 = January 1st). For instance, h276105.asc is the file with Helios 2 data for day 105, 1976.

MMS 2 Digital Signal Processor (DSP) Search Coil Magnetometer (SCM), Magnetic Field Power Spectral Density, Level 2 (L2), Fast Mode, 2 s Data

VOYAGER 1 SATURN MAGNETOMETER RESAMPLED DATA 48.0 SEC

This data set includes Voyager 1 Saturn encounter magnetometer data that have been resampled at a 48.0 second sample rate. The data set is composed of 6 columns: 1) ctime - this column contains the data acquisition time. The time is always output in the ISO standard spacecraft event time format (yyyy-mm-dd-Thh:mm:ss.sss) but is stored internally in Cline time which is measured in seconds after 00:00:00.000 Jan 01, 1966, 2) br - this column contains the radial component of the magnetic field, 3) bphi - this column contains the phi component of the magnetic field, 4) btheta - this column contains the theta component of the magnetic field, 5) bmag - this column contains the magnitude of the magnetic field, 6) flag - a flag value that indicates either software error or spacecraft hardware interference reduced confidence in this record (flag value of 1 is bad , 0 is good or unchecked). All magnetic field observations are measured in nanoTeslas. The coordinate system for this dataset is Minus Saturn Longitude System (-SLS). All of the magnetic field data are calibrated (see the instrument calibration description for more details). The SLS coordinate system is defined in Desch and Kaiser, 1981 and the reference documents for this dataset are: Ness et al, 1982 Acuna,Connerney,and Ness, 1983 Connerney,Acuna,and Ness, 1983 Behannon,Lepping,and Ness, 1983

VEGA1 HALLEY FLYBY MAGNETOMETER DATA

On MARCH 6, 1986, AT 7:20:06 UT, the Vega spacecraft passed the nucleus of comet Halley at a distance of 8,890 km with a relative velocity of 78 km/s. The magnetic field experiments MISCHA carried four fluxgate sensors, with three sensors mounted on a boom at the end of the solar panels and the fourth sensor mounted one meter closer. During the cruise phase, the TRASSA-1 mode of the instrument (1 vector/2.5 min) was used. The sensors were switched to the TRASSA-2 mode (1 vector/min) during the flyby which started roughly two days before the encounter. From 3 h before closest approach (CA) until 1 hour after CA, the HS-mode (1 vector/6s) and the DT-mode (1 vector/100ms) was used [DELVAETAL1991].