The Plasma Science (PLS) experiment aboard Voyager 2 has provided 6 different
datasets from the Neptune encounter. The datasets are distinguished by the
type of particles measured (ion or electron), and the processing of the data.
In plasma data processing, the region of space from which the data are acquired
determines some of the processing parameters. For this reason, the data are
organized by their physical location in space. The six regions/datasets are
summarized as follows:

directory       region           processing parameters
------------------------------------------------------------------------------
ELE_MAG    magnetosphere        fits to 3 Maxwellians for electrons
ION_WIND   inbound solar wind   solar wind proton density, temp., velocity, etc.
2PROTON    inner magnetosphere  assume 2 proton composition for den., temp., etc
ION_MAG    magnetosphere        assume H+ and N+ comp for den., temp., vel., etc
ION_OUTL   outbound sheath      L-mode ion data moment and fit parameters
ION_OUTM   outbound sheath      M-mode ion data moment and fit parameters

1) Electron Magnetosphere    (ELE/MAG)    1989-08-24T14:38 -> 1989-08-25T09:23
2) Inbound Solar Wind        (/ION_WIND)  1989-08-24T03:58 -> 1989-08-24T19:34
3) Magnetosphere 2 ion fit   (/ION_MAG)   1989-08-24T23:30 -> 1989-08-25T08:00
4) Closest App. 2 proton fit (/2PROTON)   1989-08-25T04:10 -> 1989-08-25T05:08
5) Outbound Sheath L-mode    (/ION_OUTL)  1989-08-26T08:36 -> 1989-08-29T23:59
6) Outbound Sheath M-mode    (/ION_OUTM)  1989-08-26T08:36 -> 1989-08-29T23:59