Find research datasets worth reusing

VG2 NEP PLS DERIVED RDR 2 PROTON MAGSPHERE 48SEC V1.0

This data set gives the best available values for ion densities, temperatures, and velocities near Neptune derived from data obtained by the Voyager 2 plasma experiment. All parameters are obtained by fitting the observed spectra (current as a function of energy) with Maxwellian plasma distributions, using a non-linear least squares fitting routine to find the plasma parameters which, when coupled with the full instrument response, best simulate the data. The PLS instrument measures energy/charge, so composition is not uniquely determined but can be deduced in some cases by the separation of the observed current peaks in energy (assuming the plasma is co-moving). In the upstream solar wind protons are fit to the M-long data since high energy resolution is needed to obtain accurate plasma parameters. In the magnetosheath the ion flux so low that several L-long spectra (3-5) had to be averaged to increase the signal-to-noise ratio to a level at which the data could be reliably fit. These averaged spectra were fit using two proton maxwellians with the same velocity. The values given in the upstream magnetosheath are the total density and the density-weighted temperature. In both the upstream solar wind and magnetosheath full vector velocities, densities and temperatures are derived for each fit component. In the magnetosphere spectra do not contain enough information to obtain full velocity vectors, so flow is assumed to be purely azimuthal. In some cases the azimuthal velocity is a fit parameter, in some cases rigid corotation is assumed. In the 'outer' magnetosphere (L>5) two distinct current peaks appear in the spectra H+ and N+. In the inner magnetosphere the plasma is hot and the composition is ambiguous, although two superimposed Maxwellians are still required to fit the data. These spectra are fit using two compositions, one with H+ and N+ and the second with two H+ components. The N+ composition is preferred by the data provider. All fit values in the magnetosphere come with one sigma errors. It should be noted that no attempt has been made to account for the spacecraft potential, which is probably about -10 V in this region and will effect the density and velocity values. In the outbound magnetosheath and solar wind both moment and fit values are given for velocity, density, and thermal speed. The signal-to-noise ratio in the M-longs is very low, especially near the magnetopause, which can result in the analysis giving incorrect values. The L-long spectra have too low an energy resolution to permit accurate determinations parameters in many regions temperature and non-radial velocity components may be inaccurate.

Voyager 1 Plasma Spectrometer (PLS) High Resolution Plasma Density, Thermal Speed, and Velocity (RTN) Data in CDF Format

Voyager 1 High-Resolution Plasma Data. The files in this directory contain the Voyager fine resolution plasma data. The plasma parameters are obtained by finding the best fit of a convected isotropic Maxwellian distribution to the data. One sigma errors are typically less than 0.5% in the speed and VR, less than 5% for the density and thermal speed, and vary greatly for VT and VN. Sampling times range from 12 to 192 sec., with sampling generally more frequent early in the mission. The velocity components are given in the RTN coordinate system, where R is radially outward, T is in a plane parallel to the solar equatorial plane and positive in the direction of solar rotation, and N completes a right-handed system. Warning: the V_t and V_n parameters are often not reliable after 1989. Please consult with us, or at least send preprints, when you use these data to prevent grievous errors or misconceptions, John Richardson, jdr@space.mit.edu.

VG1 SAT PLS DERIVED ION MAGNETOSHEATH 96SEC V1.0

This data set contains Voyager 1 plasma fit data from Saturn's magnetosphere. The fit parameters assume a convected isotropic proton Maxwellian distribution. Use of fit parameters is recommended as these are normally more accurate. Since only the first 72 or last 72 energy/charge channels are telemetered to Earth from each M-mode spectra, derived parameters change significantly only every other set of spectra so the effective time resolution is 96 second.

Voyager 2 Plasma Spectrometer (PLS) Faraday Cups A-D Low Energy Resolution Current Ion Spectra, L Mode, for Proton Energies from 10 eV to 5950 eV, 96 s Data

These Ion Current Spectra in the Jovian Magnetosphere are from the Plasma Spectrometer (PLS) Instrument on Voyager 2 during July 1979 Flyby of Jupiter. The Instrument has four Faraday Cups A, B, C, and D, the Electron Data come only from Faraday Cup D. The Data are specified in Terms of Current per Faraday Cup in femto-amperes (10^-15 A equals 1 fA) versus Channel Number and Energy (eV). This Data Set is for the PLS L Mode covering Proton (H+ Ion) Energies from 10 eV to 5950 eV at Low Energy Resolution in 16 logarithmic Energy Channels. The PLS Instrument samples only one Mode of Electron (E1, E2) or Ion (L, M) Spectra in each Time Interval, so the L Mode Data are not continuous but consecutive with the other Modes in Time. Reference: Bridge, H.S., Belcher, J.W., Butler, R.J., Lazarus, A.J., Mavretic, A.M., Sullivan, J.D., Siscoe, G.L., and V.M. Vasyliunas, The Plasma Experiment on the 1977 Voyager Mission, Space Sci. Rev., 21, 259-287, 1977.

VG2 URA PLS DERIVED SUMMARY ION FIT 48SEC V1.0

This data set contains the total ion density obtained from Voyager 2 PLS data (voltage range 10-5950 eV/Q) at Uranus by fitting the measured spectra with isotropic Maxwellian distributions. It is a subset of the data set VG2-U-PLS-5-RDR-IONFIT-48SEC. Up to three isotropic proton components (warm, hot and intermediate) were used to match the observations. These were then summed to give total ion density. This determination does not include possible plasma outside the PLS energy range derived in the charging region from 1939-2158 on day 24. It is found that if a cold component exists it will increase the total ion density by at most a factor of two. uncertainties in plasma parameters are a factor of 2 in the charging region, less than 20% elsewhere. A complete description of this data set is given in McNutt et al. (1987) and Selesnick and McNutt (1987). Data format: first six columns are time tags (6I4), last column is total ion density in CM-3 (E11.3). Values of 1.E32 indicate that the parameter could not be obtained from the data using the standard analysis technique. Additional information about this dataset and the instrument which produced it can be found elsewhere in this catalog. An overview of the data in this data set can be found in McNutt et al. (1987) and Selesnick and McNutt (1987) and a complete instrument description can be found in Bridge (1977).

IMP-8 PLS Solar Wind Weimer Propagated 60 s Resolution Data in GSE Coordinates

IMP-8 PLS propagated solar wind data and linearly interpolated to have the measurements on the minute at 60 s resolution 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.

Voyager 2 Plasma Spectrometer (PLS) Faraday Cup D High Energy Electron Current Spectra, E2 Mode, Electron Energies from 10 eV to 5950 eV, 96 s Data

These Electron Current Spectra in the Jovian Magnetosphere are from the Plasma Spectrometer (PLS) Instrument on Voyager 2 during July 1979 Flyby of Jupiter. The Instrument has four Faraday Cups A, B, C, and D, the Electron Data come only from Faraday Cup D. The Data are specified in Terms of Current per Faraday Cup in femto-amperes (10^-15 A equals 1 fA) versus Channel Number and Energy (eV). This Data Set is for the PLS E2 Mode covering Electron Energies from 10 eV to 5950 eV in 16 logarithmic Energy Channels. The PLS Instrument samples only one Mode of Electron (E1, E2) or Ion (L, M) Spectra in each Time Interval, so the E2 Data are not continuous but consecutive with the other Modes in Time. Reference: Bridge, H.S., Belcher, J.W., Butler, R.J., Lazarus, A.J., Mavretic, A.M., Sullivan, J.D., Siscoe, G.L., and V.M. Vasyliunas, The Plasma Experiment on the 1977 Voyager Mission, Space Sci. Rev., 21, 259-287, 1977.

VG2 URA PLS DERIVED RDR ELECTRON FIT 48SEC V1.0

This data set contains electron parameters in the PLS energy range (10-5950 eV) at Uranus during the Voyager 2 encounter. Parameters are calculated in several ways. Total moment density and temperature are given. Each electron spectrum is also fit with a thermal component and 1-3 hot components depending on how many Maxwellians are needed to fit the entire distribution. The moment density and temperature of the hot component is calculated after the thermal component is subtracted from the spectrum. The CHI-Square value for each fit is given. The spacecraft charge is not calculated consistently, and may result in factor of 2-3 errors in the thermal electron density. Data is unreliable inside 5 RU and in the occultation regions. At Uranus measurements were taken using both a long and a short integration time. Each 48 SEC measurement frame contained either an E1-Short and an E2-Long measurement or an E2-Short and an EI-Long. To reduce systematic errors, complete electron spectra were obtained only by combining two long or two short spectra. The instrument threshold is at a density of about 0.001 CM-3 yield data close to this value should be treated with caution. Flags in the data indicate whether the full analysis could be performed and if the data was contaminated by LECP stepping. A complete description of this data set is in Sittler et al. (1987).

VG2 NEP PLS DERIVED RDR ION MAGNETOSPHERE 48SEC V1.0

This data set gives the best available values for ion densities, temperatures, and velocities near Neptune derived from data obtained by the Voyager 2 plasma experiment. All parameters are obtained by fitting the observed spectra (current as a function of energy) with Maxwellian plasma distributions, using a non-linear least squares fitting routine to find the plasma parameters which, when coupled with the full instrument response, best simulate the data. The PLS instrument measures energy/charge, so composition is not uniquely determined but can be deduced in some cases by the separation of the observed current peaks in energy (assuming the plasma is co-moving). In the upstream solar wind protons are fit to the M-long data since high energy resolution is needed to obtain accurate plasma parameters. In the magnetosheath the ion flux so low that several L-long spectra (3-5) had to be averaged to increase the signal-to-noise ratio to a level at which the data could be reliably fit. These averaged spectra were fit using 2 proton maxwellians with the same velocity. The values given in the upstream magnetosheath are the total density and the density-weighted temperature. In both the upstream solar wind and magnetosheath full vector velocities, densities and temperatures are derived for each fit component. In the magnetosphere spectra do not contain enough information to obtain full velocity vectors, so flow is assumed to be purely azimuthal. In some cases the azimuthal velocity is a fit parameter, in some cases rigid corotation is assumed. In the 'outer' magnetosphere (L>5) two distinct current peaks appear in the spectra H+ and N+. In the inner magnetosphere the plasma is hot and the composition is ambiguous, although two superimposed Maxwellians are still required to fit the data. These spectra are fit using two compositions, one with H+ and N+ and the second with two H+ components. The N+ composition is preferred by the data provider. All fit values in the magnetosphere come with one sigma errors. It should be noted that no attempt has been made to account for the spacecraft potential, which is probably about -10 V in this region and will effect the density and velocity values. In the outbound magnetosheath and solar wind both moment and fit values are given for velocity, density, and thermal speed. The signal-to-noise ratio in the M-longs is very low, especially near the magnetopause, which can result in the analysis giving incorrect values. The L-long spectra have too low an energy resolution to permit accurate determinations parameters in many regions temperature and non-radial velocity components may be inaccurate.

VG2 NEP PLS DERIVED RDR ION OUTBND MAGSHTH M-MODE 12MIN V1.0

This data set gives the best available values for ion densities, temperatures, and velocities near Neptune derived from data obtained by the Voyager 2 plasma experiment. All parameters are obtained by fitting the observed spectra (current as a function of energy) with Maxwellian plasma distributions, using a non-linear least squares fitting routine to find the plasma parameters which, when coupled with the full instrument response, best simulate the data. The PLS instrument measures energy/charge, so composition is not uniquely determined but can be deduced in some cases by the separation of the observed current peaks in energy (assuming the plasma is co-moving). In the upstream solar wind protons are fit to the M-long data since high energy resolution is needed to obtain accurate plasma parameters. In the magnetosheath the ion flux so low that several L-long spectra (3-5) had to be averaged to increase the signal-to-noise ratio to a level at which the data could be reliably fit. These averaged spectra were fit using 2 proton maxwellians with the same velocity. The values given in the upstream magnetosheath are the total density and the density-weighted temperature. In both the upstream solar wind and magnetosheath full vector velocities, densities and temperatures are derived for each fit component. In the magnetosphere spectra do not contain enough information to obtain full velocity vectors, so flow is assumed to be purely azimuthal. In some cases the azimuthal velocity is a fit parameter, in some cases rigid corotation is assumed. In the 'outer' magnetosphere (L>5) two distinct current peaks appear in the spectra H+ and N+. In the inner magnetosphere the plasma is hot and the composition is ambiguous, although two superimposed Maxwellians are still required to fit the data. These spectra are fit using two compositions, one with H+ and N+ and the second with two H+ components. The N+ composition is preferred by the data provider. All fit values in the magnetosphere come with one sigma errors. It should be noted that no attempt has been made to account for the spacecraft potential, which is probably about -10 V in this region and will effect the density and velocity values. In the outbound magnetosheath and solar wind both moment and fit values are given for velocity, density, and thermal speed. The signal-to-noise ratio in the M-longs is very low, especially near the magnetopause, which can result in the analysis giving incorrect values. The L-long spectra have too low an energy resolution to permit accurate determinations parameters in many regions temperature and non-radial velocity components may be inaccurate.

VG2 NEP PLS DERIVED RDR ELECTRON MAGNETOSPHERE 96SEC V1.0

The electron spectra are fit using several isotropic Maxwellian distribution functions to find electron parameters. The spacecraft charge may seriously affect the density measurements. The temperature of each component is, however, independent of the spacecraft potential. To obtain the best estimate of the electron density, the encounter period is divided into four regions and four different analysis methods are used.

Voyager 1 Plasma Spectrometer (PLS) Faraday Cups A-D Low Energy Resolution Current Ion Spectra, L Mode, for Proton Energies from 10 eV to 5950 eV, 96 s Data

These Ion Current Spectra in the Jovian Magnetosphere are from the Plasma Spectrometer (PLS) Instrument on Voyager 1 during March 1979 Flyby of Jupiter. The Instrument has four Faraday Cups A, B, C, and D, the Electron Data come only from Faraday Cup D. The Data are specified in Terms of Current per Faraday Cup in femto-amperes (10^-15 A equals 1 fA) versus Channel Number and Energy (eV). This Data Set is for the PLS L Mode covering Proton (H+ Ion) Energies from 10 eV to 5950 eV at Low Energy Resolution in 16 logarithmic Energy Channels. The PLS Instrument samples only one Mode of Electron (E1, E2) or Ion (L, M) Spectra in each Time Interval, so the L Mode Data are not continuous but consecutive with the other Modes in Time. Reference: Bridge, H.S., Belcher, J.W., Butler, R.J., Lazarus, A.J., Mavretic, A.M., Sullivan, J.D., Siscoe, G.L., and V.M. Vasyliunas, The Plasma Experiment on the 1977 Voyager Mission, Space Sci. Rev., 21, 259-287, 1977.

VG2 NEP PLS DERIVED RDR ION OUTBND MAGSHTH L-MODE 48SEC V1.0

This data set gives the best available values for ion densities, temperatures, and velocities near Neptune derived from data obtained by the Voyager 2 plasma experiment. All parameters are obtained by fitting the observed spectra (current as a function of energy) with Maxwellian plasma distributions, using a non-linear least squares fitting routine to find the plasma parameters which, when coupled with the full instrument response, best simulate the data. The PLS instrument measures energy/charge, so composition is not uniquely determined but can be deduced in some cases by the separation of the observed current peaks in energy (assuming the plasma is co-moving). In the upstream solar wind protons are fit to the M-long data since high energy resolution is needed to obtain accurate plasma parameters. In the magnetosheath the ion flux so low that several L-long spectra (3-5) had to be averaged to increase the signal-to-noise ratio to a level at which the data could be reliably fit. These averaged spectra were fit using 2 proton maxwellians with the same velocity. The values given in the upstream magnetosheath are the total density and the density-weighted temperature. In both the upstream solar wind and magnetosheath full vector velocities, densities and temperatures are derived for each fit component. In the magnetosphere, spectra do not contain enough information to obtain full velocity vectors, so flow is assumed to be purely azimuthal. In some cases the azimuthal velocity is a fit parameter, in some cases rigid corotation is assumed. In the 'outer' magnetosphere (L>5) two distinct current peaks appear in the spectra H+ and N+. In the inner magnetosphere the plasma is hot and the composition is ambiguous, although two superimposed Maxwellians are still required to fit the data. These spectra are fit using two compositions, one with H+ and N+ and the second with two H+ components. The N+ composition is preferred by the data provider. All fit values in the magnetosphere come with one sigma errors. It should be noted that no attempt has been made to account for the spacecraft potential, which is probably about -10 V in this region and will effect the density and velocity values. In the outbound magnetosheath and solar wind both moment and fit values are given for velocity, density, and thermal speed. The signal-to-noise ratio in the M-longs is very low, especially near the magnetopause, which can result in the analysis giving incorrect values. The L-long spectra have too low an energy resolution to permit accurate determinations parameters in many regions temperature and non-radial velocity components may be inaccurate.

Voyager 1 Plasma Spectrometer (PLS) Faraday Cup D High Energy Electron Current Spectra, E2 Mode, Electron Energies from 10 eV to 5950 eV, 96 s Data

These Electron Current Spectra in the Jovian Magnetosphere are from the Plasma Spectrometer (PLS) Instrument on Voyager 1 during March 1979 Flyby of Jupiter. The Instrument has four Faraday Cups A, B, C, and D, the Electron Data come only from Faraday Cup D. The Data are specified in Terms of Current per Faraday Cup in femto-amperes (10^-15 A equals 1 fA) versus Channel Number and Energy (eV). This Data Set is for the PLS E2 Mode covering Electron Energies from 10 eV to 5950 eV in 16 logarithmic Energy Channels. The PLS Instrument samples only one Mode of Electron (E1, E2) or Ion (L, M) Spectra in each Time Interval, so the E2 Data are not continuous but consecutive with the other Modes in Time. Reference: Bridge, H.S., Belcher, J.W., Butler, R.J., Lazarus, A.J., Mavretic, A.M., Sullivan, J.D., Siscoe, G.L., and V.M. Vasyliunas, The Plasma Experiment on the 1977 Voyager Mission, Space Sci. Rev., 21, 259-287, 1977.

Voyager 2 Plasma Spectrometer (PLS) Faraday Cup D Low Energy Electron Current Spectra, E1 Mode, Electron Energies from 10 eV to 140 eV, 96 s Data

These Electron Current Spectra in the Jovian Magnetosphere are from the Plasma Spectrometer (PLS) Instrument on Voyager 2 during July 1979 Flyby of Jupiter. The Instrument has four Faraday Cups A, B, C, and D, the Electron Data come only from Faraday Cup D. The Data are specified in Terms of Current per Faraday Cup in femto-amperes (10^-15 A equals 1 fA) versus Channel Number and Energy (eV). This Data Set is for the PLS E1 Mode covering Electron Energies from 10 eV to 140 eV in 16 logarithmic Energy Channels. The PLS Instrument samples only one Mode of Electron (E1, E2) or Ion (L, M) Spectra in each Time Interval, so the E1 Data are not continuous but consecutive with the other Modes in Time. Reference: Bridge, H.S., Belcher, J.W., Butler, R.J., Lazarus, A.J., Mavretic, A.M., Sullivan, J.D., Siscoe, G.L., and V.M. Vasyliunas, The Plasma Experiment on the 1977 Voyager Mission, Space Sci. Rev., 21, 259-287, 1977.

VG2 URA PLS DERIVED SUMM ELECTRON BROWSE 48SEC V1.0

This data set contains the thermal electron density and temperature in the PLS energy range (10-5950 eV) from Voyager 2 at Uranus derived by fitting the low energy electron component with a Maxwellian distribution, and the moment density and temperature of the hot electrons calculated after the signal from the thermal component is subtracted from the electron spectra. The moment density and temperature obtained by integrating over the entire measured distribution function are also given. This is a subset of the data set VG2-U-PLS-5-RDR-ELEFIT-48SEC which should be obtained before this data is used, since it contains information on the type of fit performed and LECP contamination of the data. Spacecraft charging may result in underestimation of thermal electron density in some regions. The first six columns are the time tag (year, day, hour, min, sec, msec), columns 7 and 8 are the total moment density and temperature, columns 9 and 10 are the fit density and temperature of the thermal electron component, and 11 and 12 are the moment density and temperature of the suprathermal electrons. Each row has the format (6I4,6E12.4). Values of 1.E32 indicate that the parameter could not be obtained from the data using the standard analysis technique. Additional information about this dataset and the instrument which produced it can be found elsewhere in this catalog. An overview of the data in this data set can be found in Sittler et al. (1987) and a complete instrument description can be found in bridge (1977).

Voyager 2 Plasma Spectrometer (PLS) Faraday Cups A-D High Energy Resolution Current Ion Spectra, M Mode, for Proton Energies from 10 eV to 5950 eV, 96 s Data

These Ion Current Spectra in the Jovian Magnetosphere are from the Plasma Spectrometer (PLS) Instrument on Voyager 2 during July 1979 Flyby of Jupiter. The Instrument has four Faraday Cups A, B, C, and D, the Electron Data come only from Faraday Cup D. The Data are specified in Terms of Current per Faraday Cup in femto-amperes (10^-15 A equals 1 fA) versus Channel Number and Energy (eV). This Data Set is for the PLS M Mode covering Proton (H+ Ion) Energies from 10 eV to 5950 eV at High Energy Resolution in 128 logarithmic Energy Channels. The PLS Instrument samples only one Mode of Electron (E1, E2) or Ion (L, M) Spectra in each Time Interval, so the M Mode Data are not continuous but consecutive with the other Modes in Time. Reference: Bridge, H.S., Belcher, J.W., Butler, R.J., Lazarus, A.J., Mavretic, A.M., Sullivan, J.D., Siscoe, G.L., and V.M. Vasyliunas, The Plasma Experiment on the 1977 Voyager Mission, Space Sci. Rev., 21, 259-287, 1977.

VG2 URA PLS DERIVED RDR ION FIT 48SEC V1.0

This data set contains the ion densities and temperatures along with formal 1 Sigma errors obtained from Voyager 2 PLS data (voltage range 10-5950 eV/Q) at Uranus by fitting the measured spectra with isotropic Maxwellian distributions. Up to three isotropic proton components (warm, hot and intermediate) were used to match the observations. The plasma was assumed to be rigidly corotating. Uncertainties in plasma parameters are a factor of 2 in the charging region from 1939-2158 on day 24, less than 20% elsewhere. A complete description of this data set is given in McNutt et al. (1987) and Selesnick and McNutt (1987).