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WIND Spacecraft

Wind Project Scientist
Lynn B. Wilson III
(301) 286-6487
lynn.b.wilson [at] nasa.gov

Two Columns



WIND Instrument and Data Documentation



WIND Magnetic Field Investigation (MFI)


  • Instrument Description

    • The Wind Magnetic Field Investigation (MFI) is composed of two fluxgate magnetometers located at 2/3 of the way out and at the end of a 12 m boom. The instrument measures DC vector magnetic fields up to a time resolution of 22 or 11 vectors/sec depending on the telemetry mode of the spacecraft. A complete description of the instrument can be found in the Space Science Reviews article by Lepping et al.. Additional information can be found on the Instrument Web Page.

  • Calibration and Data Product Documentation

    • The primary data processing algorithms employed in generating the MFI data products are described by Farrell et al. [1995].

    • The calibration method of the spin axis component of the magnetic field is described by Leinweber, H. K. et al., Meas. Sci. Technol., 19, 055104, 2008.

    • The largest source of uncertainty in the MFI data is the inherent rms noise due to averaging. The vector rms variation is computed for all data points and for all time averages from the raw telemetered data and is included in the publicly distributed data files.

    • Proper calibration of the magnetic field data requires long duration measuremets. In order to provide data at the earliest possible time, calibration takes place in three stages resulting in version 3, 4, and 5 data products. The processes used for each step are described in version descriptin document..

WIND Solar Wind Experiment (SWE) Faraday Cup - Ion Data


  • Instrument Description
  • Calibration and Data Product Documentation

    • A detailed description of the algorithms and procedures used to generate the Faraday Cup data products is provided in the PhD Thesis of J. Kasper.

    • Detailed, point-by-point error analysis is included in each data file.

    • The systematic uncertainties of the measurements, calibrated against other Wind instruments and based on basic physical principles, are discussed in Kasper et al. [2006].

WIND Solar Wind Experiment (SWE) Electron Data


  • Instrument Description

    • The SWE electron sub-system consists of two electrostatic analyzers, the vector spectrometer (VEIS) and the Strahl spectrometer. They were both designed to measure the solar wind electron distribution function. The original configuration of the detectors are described by Ogilvie et al. [1995].

    • After the failure of the high voltage power supply of VEIS in 2001, the Strahl detector was reconfigured to recover most of the measurement capabilities. An updated version of the SWE Space Science Reviews article reflecting the changes is also available.

    • The history and description of the SWE electron instruments can also be found at the instrument Web site.

  • Calibration and Data Product Documentation

    • The algorithms used to generate the electron pitch angle and strahl data is described in an internal memo.

    • Complete description of teh various electron data products can be found at the instrument Web site.

    • Extensive documentation for each data product is also provided in the headers of the CDF files.

Wind 3D Plasma Analyzer


  • Instrument Description

    • The Wind 3DP instrument consists of six different sensors. There are two electron (EESA) and two ion (PESA) electrostatic analyzers with different geometrical factors and field-of-views covering the energy range from 3 eV to 30 keV. There are also a pair of solid state telescopes (SST) that measure electrons with energies up to 400 keV and protons with energies up to 6 MeV. The instrument is fully described by Lin et al. [1995].

    • Some more documenation of the instrument is also available from the 3DP Home Page.

  • Calibration and Data Product Documentation

Wind SMS Suprathermal Particle Data


  • Instrument Descrition

    • The Wind SMS instrument suite is composed of three separate instruments. The SupraThermal Ion Composition Spectrometer (STICS) determines the mass, mass per charge, and energy for ions in the energy range of 6-230 keV/e. The high resolution mass spectrometer (MASS) determines elemental and isotopic abundances from 0.5 to 12 keV/e. Finally, The Solar Wind Ion Composition Spectrometer (SWICS) determines mass, charge, and energy for ions in the energy range of 0.5 to 30 keV/e. The SWICS "stop" MCP experienced a failure resulting in reduced capabilities for this instrument. These instruments are fully described by Gloeckler et al. [1995].

  • Calibration and Data Product Documentation

    • The methodology of instrument calibration and data product generation is detailed in Ghielmetti et al. [1983].

    • Detailed discussion of the instrument response function and calibration results are provided in the PhD Thesis of K. Chotoo.

    • A new software system has been developed which automates many data analysis functions previously done manually. This system first simultaneously assigns events to specific ion species, removing any overlap and using the statistical properties of the measurements to maximum advantage. It then uses these assigned events to construct phase space density distribution functions and corrects these for the effects of instrument efficiency and sampling geometry. Finally, it outputs these distribution functions, error estimates, and count rates for each ion along with many intermediate products that facilitate detailed analysis. The release notes of these data products contain further details.

Wind EPACT High Energy Particle Data


  • Instrument Description

    • The Energetic Particles: Acceleration, Composition and Transport (EPACT) investigation consists of multiple telescopes. The highest energy telescopes (APE and IT) have failed early in the mission. However, the Low Energy Matrix Telescope (LEMT) covering energies in the 1-10 MeV/nuc range and the Suprethermal Energetic Particle telescope (STEP) measuring ions heavier than protons in the 20 keV-1 MeV/nuc range still continue to provide valuable data. These instruments are described in detail by Von Rosenvinge et al. [1995].

    • Further information on the instrument is available on the Instrument Web Page.

  • Calibration and Data Product Documentation

    • The particle detection algorithm is described by Von Rosenvinge et al. [1995].

    • The content of the Omnidirectional Intensity data files is descibed by the documentation in the data directory.

    • The content of the Sectored Count data files is described in the documentation in the data directory.

    • The content of the Temperature Anisotropy data files is described in the documentation in the data directory.

Wind WAVES Radio and Plasma Waves Data


  • Instrument Description

    • The WAVES experiment on the Wind spacecraft is composed of three orthogonal electric field antenna and three orthogonal search coil magnetometers. The electric fields are measured through five different receivers: Low Frequency FFT receiver called FFT (0.3 Hz to 11 kHz), Thermal Noise Receiver called TNR (4-256 kHz), Radio receiver band 1 called RAD1 (20-1040 kHz), Radio receiver band 2 called RAD2 (1.075-13.825 MHz), and the Time Domain Sampler called TDS. The electric field antenna are dipole antennas with two orthogonal antennas in the spin plane and one spin axis stacer antenna. Calibration found that the effective antenna lengths are roughly 41.1 m, 3.79 m, and 2.17 m for the X, Y, and Z antenna respectively [Note: These are preliminary estimates and may change.]. The orientation of the search coils are aligned with the dipole antennas.

    • The TDS receiver allows one to examine the electromagnetic waves observed by Wind as time series waveform captures. There are two modes of operation, TDS Fast (TDSF) and TDS Slow (TDSS). TDSF returns 2048 data points for two components of the electric field, typically Ex and Ey (i.e. spin plane components), with little to no gain below about 120 Hz. TDSS returns four field vectors with three electric(magnetic) field components and one magnetic(electric) component. The search coils show a gain roll off around 3.3 Hz.

    • The instrument is fully described by Bougeret et al. [1995].

    • Some additional technical information is also available on the Instrument Web Page.

  • Calibration and Data Product Documentation

    • The calibration of the TNR receiver that allowed the estimation of electron densities based on the identification of the electron plasma frequency is described by Maksimovich et al. [1998].

    • The documentation for the WAVES 1-minute average data can be found on the Instrument Web Page.

Wind KONUS and TGRS Data


  • Instrument Description

    • KONUS remains a very active partner in the Gamma-ray Coordinates Network (GCN) (work done by Dr. Scott Barthelmy) and the Interplanetary Network (maintained by Dr. Kevin Hurley). Notifications of astrophysical transients are sent worldwide instantly from KONUS, and are of importance in the subsequent positioning of telescopes everywhere. Thus, the instrument remains an active contributor to the astrophysical community.

    • KONUS continues to work with other gamma-ray space telescopes like the Swift Mission.

Additional Information