Overview of ISEE 3 Magnetic Field Data Sets
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In addition to the data set briefly noted below, users should be aware that
there is a merged magnetic field and plasma data set (2_min_merged_mag_plasma)
in the higher level directory (...isee/isee3/) where the "magnetic fields" and
"plasma" headings reside.

This directory contains the following magnetic field data sets from ISEE 3.
Each data set is described more fully in the readme file found in its data set
directory and in references given therein.


1. 0.16sec_ascii_gz
   NSSDC ID: SPHE-00268
   Old ID: 78-079A-02R

   This is the highest-time-resolution data available from the vector
magnetometer. Because of the large size of the data set, the data files were
compressed by gzip.


2. 1min_1hr_1d_ascii
   NSSDC ID: SPHE-00673
   Old ID: 78-079A-02D

   This is a binary data set with long records in a very complicated format.
It contains the parameters averaged over each minute, over each hour, and over
the whole day. The difficulty in working with this data set format led to the
generation of a new data set by extracting only the 1-minute averaged data
from this data set and converting it to ascii, which is data set 3 below. The
additionand of spacecraft position in heliocentric coordinates created data
set 4 below.


(3-4). 1min_ascii_extracted
   This is actually two different data sets, each covering its own unique time
span: first the earth-centered phase (1978-1983); and then the heliocentric
phase (1984-1990) of the ISEE 3 mission.

3. 1min_1978_1983 (Geocentric)
   NSSDC ID: SPHE-00843
   Old ID: 78-079A-02T

   These data were extracted from the complicated binary format of data set 2
above, and converted to ascii format. In addition, the spacecraft positions,
in earth-centered GSE coordinates, were extracted from their location in the
original header records, and inserted at the end of each new data set record.
Because of the difference in time resolution of the header position data and
the magnetic field data, the same position vector components appear multiple
times, until the next provided header record. This data set ends at the end of
1983, so only the earth-centered position coordinates were needed.


4. 1min_hgi_1984_1990 (Heliocentric)
   NSSDC ID: SPHE-00844
   Old ID: 78-079A-02U

   These data were extracted from the complicated binary format of data set 2
above, and converted to ascii format, just as data set 3 above. But in
addition to insertion of the earth-centered GSE coordinates, the spacecraft
positions were also converted to heliocentric coordinates HGI and inserted
into each data record.

   The heliocentric coordinates were added only for the heliocentric phase of
the ISEE 3 spacecraft, which was maneuvered out of the Earth-Moon system as of
December 22, 1983, and into a heliocentric orbit ahead of the Earth, on a
trajectory intercepting that of Comet Giacobini-Zinner. Later it would be
positioned upstream in the solar wind from Comet Halley when other spacecraft
passed through that comet.


5. 1min_ascii_with_sw_speed
   NSSDC ID: SPMS-00705
   Old ID: 78-079A-02S

   This data set was converted to ASCII at NSSDC from a binary data set that
was generated by combining data from the Solar Wind Plasma instrument and from
the Magnetic Field instrument. The only parameter from the Solar Wind Plasma
instrument is the solar wind speed (magnitude only, not the vector). Data records
are present for every minute of every day during this time span, even if there
are no valid data. Missing or non-valid data are indicated by special values. See
the 00readme.txt file for the data set for more details.

Last updated: 11/05/02, HKH