Helios 1 E3 Magnetometer: Hour-Averaged Solar Wind Magnetic Field Data, 1974-1981

Hour-averaged magnetic field vectors from the Helios 1 spacecraft exploring the inner heliosphere from 0.3 to 1 AU. The data was collected by a joint Italian-American team using a dual tri-axial fluxgate magnetometer with high sensitivity, ranging from 0.03 to 0.84 nT. Records span from 1974 to 1981 and include time, field intensity, vector components, standard deviations, and instrument mode indicators.

Use Cases

• Modeling solar wind propagation and structure based on magnetic field vector data.
• Analyzing long-term trends in interplanetary magnetic field intensity over the 1974-1981 solar cycle.
• Calibrating or validating space weather models using in-situ measurements from inside Earth's orbit.
• Studying instrument performance and data artifacts related to the on-board 'average' mode handling of range changes.

Strengths

• Data covers a significant 7-year period (1974-1981) of solar activity.
• Instrument provided high sensitivity measurements, with resolutions as fine as 0.03 nT.
• Each record includes derived statistics like standard deviations and the count of fine-scale points used in the average.

Limitations

• The 'average' instrument mode, used a minority of the time, may have incorrectly handled range changes, and the data was not filtered for this effect.
• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment for large-scale statistical analysis.

Provenance

Source

National Aeronautics and Space Administration (NASA), specifically the joint Rome-GSFC magnetic field experiment team led by F. Mariani and N.F. Ness.

Collection Method

Collected by the dual tri-axial fluxgate magnetometer instrument on the Helios 1 spacecraft, with on-board averaging to produce hour-averaged vectors.

Time Range

1974 to 1981

Freshness

Last updated 2026-03-13 07:33:51.360072; freshness should be verified.

Geography

Inner heliosphere, from inside Earth's orbit to approximately 0.3 Astronomical Units (AU) from the Sun.