Data Set Overview
    =================
      The following describes the nature of instrument operation
      during the various periods for which IES data are available in
      this submission.  In all cases the data are calibrated differential
      electron and ion energy flux as function of energy, azimuth (direction
      in the instrument symmetry plane) and elevation (angle above or below
      the symmetry plane).

      Rosetta Extension 1 (EXT1) covers the period from 2016-January-01 to
      2016-April-05. IES observed solar wind plasma continuously throughout
      this phase, except for the interval of January 4-9, 2016. There are
      periods in this phase when we are unable to separate solar wind protons
      from the picked-up ions. During these intervals, no solar wind proton
      moments are reported. IES detected solar wind alpha particles during
      this phase. There are some intervals where proton moments are not
      reported, but alpha moments are reported. This is due to the fact that
      alphas are deflected less than protons, and the alpha population is at
      higher energies than picked up ions, which are mixed with the proton
      population. IES measures different electron energy populations
      throughout this phase, but electron moments are reported as a single
      unseparated population.

    Processing
    ==========
      All Rosetta Plasma Consortium (RPC) data packets are transmitted
      together during downlinks with Rosetta. RPC data are retrieved
      from the Data Distribution System (DDS) at European Space
      Operations Centre (ESOC) to a central RPC data server at
      Imperial College London. Data for IES is copied from the RPC
      central data server by IESGS at Southwest Research Institute.

      The pipeline processing software is the IES Ground System
      (IESGS). IESGS extracts IES CCSDS packets from the RPC
      collective data files stored on the RPC central data server at
      Imperial College. These packets are used to build ion and
      electron data products. The data products are grouped by date
      and written out to PDS compliant archive data files. One data
      file is created for each day. IESGS also generates the labels
      for the archive data files. IES science products, archive and
      label files, and limited spectrograms are available to team
      scientists on the IESGS website.

      For information on how the derived data files are created
      from calibrated data files, please see DOCUMENT\MOMENTS_CALCULATION\
      MOMENTS_CALCULATION.PDF.

    Coordinate System
    =================
      In order to determine IES pointing, attitude data for the
      Rosetta spacecraft is obtained through SPICE kernels.

      Level 5 files use Comet-centered Solar EQuatorial (CSEQ) as the
      reference frame to specify the velocity direction components. This is
      a common frame used in many other data sets and is referenced as
      '67P/C-G_CSEQ' in SPICE.

      SUB_SPACECRAFT_LATITUDE, SUB_SPACECRAFT_LONGITUDE are given in
      the Cheops reference frame. These parameters are computed at
      time t=START_TIME. Distances are given in km, angles in
      degrees.

Confidence Level Overview
    =========================
      This dataset is used by the IES science team after processing.
      This is done to ensure that the archived data contains good,
      valid products.

      Caveat about using IES Level 3 Differential Energy Flux data: The
      background subtraction technique used in the production of the Level 3
      Differential Energy Flux data does not work well for certain modes and as
      a result, the flux values may be slightly different from nominal. Please
      contact the IES team before using the data. Once the background
      subtraction issue is resolved, the IES team will deliver updated data.

    Review
    ======
      This archival data set was examined by the IES science team
      prior to submission to the NASA Planetary Data System (PDS) and ESA
      Plantetary Science Archive (PSA). It was reviewed by PDS, PSA, and the
      Rosetta data archive working group.
      The current set was peer reviewed scientifically in 2016 by external
      experts and the recommendations and fixes have been implemented.

    Limitations
    ===========
      None.