ISEE 3 Triaxial Helium Magnetometer: 0.16sec_ascii_gz data

Old ID: 78-079A-02R
These data are the highest-time-resolution data available from this instrument. The data are separated into four files per day, each with the date (YYDDD) and starting hour (00, 06, 12, or 18) embedded in the data file name. The ASCII files were compressed using gzip, and must be de-compressed before using. Some or all files from any particular day may be absent due to absence of data. Files are located in yearly sub-directories.

The data items, in order, are:
Year (2-digit)
Day of year (Jan. 1 is 001)
Hour (0 - 23)
Minute (0 - 59)
Seconds (0 - 59.999)
BX (nT)
BY (nT)
BZ (nT)
BT (nT)

The magnetic field is in Solar Ecliptic coordinates, where +Z is the northward perpendicular to the Ecliptic and +X is in the direction from the spacecraft to the Sun. BT is the field magnitude; since these data are not averaged, BT is just the magnitude of the vector (BX,BY,BZ).

When using these data in any publication, please acknowledge the Principal Investigator, E. J. Smith, and the National Space Science Data Center.
These data, in ASCII format compressed by gzip, were converted to ASCII by NSSDC from the original UCLA flat-file pair format (binary data file and short ASCII header file). Software provided by J. Wolf of the PI team was used in making the conversion, but was modified for use in the NSSDC system, and for certain other changes in accessing the data and in selecting data intervals for output.

These data were separated by NSSDC into 1/4 - day files, with names that denote the year, day of year and the starting hour: i3_84321_18.txt.gz, for example, denotes ISEE3 data, from year 1984, day 321, and hour 18. Note that hours here range from 0 through 23.

Note that this data set does not contain any spacecraft position information. There is an ephemeris data set available at ...isee3/traj/hourly_magnetospheric/isee3_dp_ephem.asc that has spacecraft position at approximately hourly intervals throughout the spacecraft lifetime. The Readme documentation for this data set is at ...isee3/traj/hourly_magnetospheric/aareadme_isee3_dp_ephem.
For complete information about the three ISEE spacecraft and all their experiments see the NSSDC space physics web pagee at, and select the desired spacecraft from the list below the text, or select one of the specialized data-access systems in the browser-expandable upper panel.
Original: hkh, 04/12/00
Updated: hkh, 8/09/02