JUNO SPK Files
===========================================================================
 
     This ``aareadme.txt'' file describes contents of the kernels/spk
     directory of the JUNO SPICE data server. It was last modified on
     August 2, 2017. Contact Chuck Acton (818-354-3869,
     Chuck.Acton@jpl.nasa.gov) or Boris Semenov (818-354-8136,
     Boris.Semenov@jpl.nasa.gov) if you have any questions regarding this
     data.
 
 
Brief summary
--------------------------------------------------------
 
     This directory contains the SPICE SP-Kernel files for the JUNO
     mission, including nominal and operational spacecraft trajectory SPKs,
     generic planetary and satellite ephemerides SPKs, and JUNO structure
     locations SPKs.
 
 
Naming Scheme
--------------------------------------------------------
 
     The naming scheme for cruise operations JUNO SPKs produced by NAV is:
 
        -- Reference trajectory, delivered as needed:
 
              spk_ref_YYMMDD_YYMMDD_yymmdd.bsp
 
        -- Reconstructed trajectory SPK, delivered as needed:
 
              spk_rec_YYMMDD_YYMMDD_yymmdd.bsp
 
        -- Predicted trajectory:
 
              TBD
 
     The naming scheme for orbital operations JUNO SPKs produced by NAV is:
 
        -- Reference trajectory:
 
              spk_ref_YYMMDD_YYMMDD_yymmdd.bsp
 
        -- Reconstructed trajectory covering one orbit -- apojove -
           10 days to next apojove - 10 days -- delivered 3 days
           before apojoves:
 
              spk_rec_YYMMDD_YYMMDD_yymmdd.bsp
 
        -- Strategic trajectory delivered every 4 weeks and covering
           5-6 months:
 
              spk_pre_YYMMDD_YYMMDD_yymmdd_jmxxyy.bsp
 
        -- Tactical/OTM traj delivered every 7-8 weeks and covering
           about 7 months:
 
              spk_pre_YYMMDD_YYMMDD_yymmdd_otmxx_p.bsp
              spk_pre_YYMMDD_YYMMDD_yymmdd_otmxx_f.bsp
 
        -- No-burn trajectory (for DSN, NOT delivered
           in nominal situations):
 
              spk_nob_YYMMDD_YYMMDD_yymmdd_otmxxPA_f.bsp
 
     where
 
           YYMMDD   coverage start and STOP UTC/SCET (required);
 
           yymmdd   file release date (required);
 
 
Naming Scheme for Merged, Ever-growing JUNO Spacecraft SPKs
 
     The naming scheme for merged, ever-growing JUNO SPKs for orbital
     phases is:
 
           juno_TYPE_orbit.bsp
 
     where
 
           TYPE     data type (required):
 
                       rec     for reconstructed
                       pred    for predicted
 
 
Naming Scheme for Generic Planetary Ephemeris SPKs
 
     The naming scheme for generic planetary SPKs is:
 
           deNNN.bsp
 
     where
 
           NNN      DE version (required; e.g. 421);
 
 
Naming Scheme for Generic Satellite Ephemeris SPKs
 
     The naming scheme for generic satellite SPKs is:
 
           jupNNN[_EXTRA].bsp
 
     where
 
           NNN      satellite ephemeris number (required; e.g. 230);
 
           EXTRA    additional information token (optional; e.g. _rocks);
 
 
Naming Scheme for JUNO Structure Locations SPKs
 
     The naming scheme for JUNO structure locations SPKs is:
 
           juno_struct_vNN.bsp
 
     where
 
           NN       version number (required);
 
 
Supplementary/Meta Information Files.
--------------------------------------------------------
 
     There are two types of supplementary/meta information files provided
     with the SPK files: detached label files and orbit number files.
 
 
SPK Label Files.
 
     Detached label files have the same names as the corresponding SPK
     files with the additional extension ".lbl" appended at the end.
 
     For all files except the merged products created by NAIF, the labels
     do NOT have any specific structure and they contain rather ``raw''
     information combined from the following sources: file SFDU label (if
     such was present), contents of the comment area and file summary
     output by the BRIEF utility program. Most of these labels are created
     automatically "on the fly" and are planned to be re-processed before
     final data archiving with the PDS.
 
     For the merged products created by NAIF, the label contains more
     structured and organized information including detailed description of
     the data sources, the way the file was created, etc.
 
 
Orbit Number Files.
 
     Orbit number files are present for the corresponding merged products
     created by NAIF for the orbital phase of the mission. Orbit number
     files have the same names as the corresponding SPK file but with the
     extension ".bsp" replaced by ".orb". These orbit number files contain
     data that follow the "apoapsis-to-apoapsis" orbit numbering scheme --
     with the orbit number changing at apoapsis. The information contained
     in the orbit number files includes the orbit number, apoapsis UTC and
     SCLK time, periapsis UTC time and additional information for apoapsis
     such as subsolar and subspacecraft longitude/latitude.
 
 
Details Regarding Merged SPK File for Current Phase
--------------------------------------------------------
 
     During orbital phase of the mission, the merged SPK file(s) is updated
     (appended) automatically every time JUNO NAV delivers a new regular OD
     solution SPK file. Normally these is no label available for this(e)
     file(s). The corresponding orbit number file is also updated
     automatically once updating of its "parent" SPK file is finished.