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LEPEDEA 3-D Proton+Electron Distribution Functions; 128/512-Seconds


Availability: Archived at NSSDC, accessible from elsewhere

Time span: 1977-11-01 to 1986-06-01


This data set consists of three-dimensional distribution function values, f(v), from the LEPEDEA instrument at a time resolution of 128 seconds (high bit rate; 4 seconds x 32 energy channels) or 512 seconds (low bit rate; 16 seconds x 32 energy channels) for the full range of energies and angles of the instrument. The eight polar look directions are 13, 28, 55, 90, 125, 152, 167, and 180 degrees. The sixteen azimuthal angles (look directions) are 0, 23, 45, 68, 90, 113, 135, 158, 180, 203, 225, 248, 270, 293, 315, and 338 degrees. The detector covers the 1 eV to 45 keV or the 215 eV to 45 keV energy range (depending on the mode) in 32 steps. A data record is written for each energy step. After one cycle header record, the data records for that cycle are written sequentially in order of increasing energy steps. Some energy steps are omitted (usually because of data gaps). Each data record consists of the year, the day of year (January 1 = Day 1), the milliseconds of day, and 16 groups of data values. Each group corresponding to the sixteen azimuthal sectors and contains: 10 quantities which correspond to proton f(v) for detectors 2-6 and electron f(v) for detectors 2-6 [before 1983], or 12 quantities which correspond to proton f(v) for detectors 1-3, 5-7, and electron f(v) for detectors 1-3, 5-7 [after 1983]. The ecliptic plane detectors (4P and 4E) lost a great deal of sensitivity after 1983, making the data processing more complicated and the data less useful in regions where counting rates are low.

Data are available online at

Alternate Names

  • LEPEDEA 3-D Distr Func 128/512 S


  • Space Physics: Magnetospheric Studies
  • Space Physics: Heliospheric Studies


  • 77-102A-03G

Additional Information



Questions and comments about this data collection can be directed to: Dr. H. Kent Hills



NameRoleOriginal AffiliationE-mail
Mr. Robert M. CandeyGeneral ContactNASA Goddard Space Flight
Dr. Cheryl Y. HuangGeneral ContactUniversity of
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