PDS_VERSION_ID = PDS3
DATA_SET_ID = "JNO-J/SW-JAD-3-CALIBRATED-V1.0"
RECORD_TYPE = STREAM
OBJECT = TEXT
PUBLICATION_DATE = 2024-09-24
NOTE = "ERRATA.TXT reflects any known deficiencies
with files contained on volume JNOJAD_3001."
END_OBJECT = TEXT
END
ERRATA
This file contains a list of all deficiencies and irregularities that are
known to exist at the time of the publication date above. Any errors
detected with this volume will be published on subsequent volumes in this
volume set.
------------------------------------------------------------------------------
[Added 2017-Oct-31]
Version 1 files of JAD_L30_LRS_ELC_ANY_CNT_yyyyddd_V01 have an incorrect
MAG_VECTOR object - fixed for version 2 files. This was due to a typo that
used the wrong spacecraft clock to despin the MAG_VECTOR in the version 01
files. This bug only affected the LRS electrons file's MAG_VECTOR object.
This is fixed in Version 2 files - and is what prompted a version 2.
Version 1 files in this volume are from 2015 to 2017-140 only.
Version 2 files were made for this time range.
No known publication used this incorrect data, all the GRL special issue
papers from earlier in 2017 did not use the low rate science MAG_VECTOR.
Other changes between version 1 and version 2 are just improvements.
The high rate science electron file have an improved MAG_VECTOR in version 2,
the version 1 MAG_VECTOR is good, but a better calibration is used for
version 2. Some descriptions in the LBL/FMT files are improved or fixed a
typo, but are not meaningful changes. See the CALIB directory for a file
stating differences between version 1 and version 2 files.
------------------------------------------------------------------------------
2019-12-16: All Version 2 DATA/2018/297 files replaced with newer products,
which is indicated in the product creation times. All files remain Version 2.
The previous Version 2 files have been moved to the superseded area.
------------------------------------------------------------------------------
2019-12-17: Version 1 DATA from 2015090 to 2017141 replaced with Version 2.
------------------------------------------------------------------------------
[Added 2020-Aug-27]
This file-pair should not be in this PDS volume, and should not be used:
CALIB/LUT_4_01_ENERGY_V01.CSV
CALIB/LUT_4_01_ENERGY_V01.LBL
They were put on to the PDS before we realized they have a time dependence.
There were renamed (exact same file contents otherwise) and put on the PDS as:
CALIB/LUT_4_01_A_ENERGY_V01.CSV
CALIB/LUT_4_01_A_ENERGY_V01.LBL
(This allowed for LUT_4_01_B_ENERGY_V01.CSV/LBL for a later date range)
------------------------------------------------------------------------------
[Added 2020-Aug-27]
An incorrect ISSUES object in the level 2 version 01 files (used to generate
the Version 02 files in this Level 3 dataset) meant that three Level 3 records
are missing half their data (replaced by MISSING_CONSTANT values).
The three affected files and records (noted by TIMESTAMP_WHOLE, two per
record) are:
JAD_L30_HLS_ION_LOG_CNT_2017037_V02.DAT : TIMESTAMP_WHOLE of [539633324, 0]
JAD_L30_HLS_ION_LOG_CNT_2017056_V02.DAT : TIMESTAMP_WHOLE of [541255392, 0]
JAD_L30_HLS_ION_TOF_CNT_2017188_V02.DAT : TIMESTAMP_WHOLE of [552721028, 0]
(TIMESTAMP_WHOLE of 0 is the MISSING constant value for TIMESTAMP_WHOLE in
these files, indicating the half missing record.)
These are fixed later versions of those files, this only affected those three
records in version 02 files.
------------------------------------------------------------------------------
NOTE: 2022-09-02
Version 01 and Version 02 files have no background removed from the DATA.
Version 03 files (JADE-E only, there are no version 03 JADE-I files) had
a time independent background removed. Version 04 files have a background
removed with a time dependent backround (per-orbit coefficients for the
background calculations). In all cases, the background removed from DATA is
provided in the BACKGROUND object.
------------------------------------------------------------------------------
NOTE: 2023-10-12
Instrument name corrected to be
INSTRUMENT_NAME = JOVIAN AURORAL DISTRIBUTIONS EXPERIMENT
Instead of
INSTRUMENT_NAME = JOVIAN AURORAL PLASMA DISTRIBUTIONS EXPERIMENT
(without PLASMA).
------------------------------------------------------------------------------
[Added 2024-Jul-18]
For Versions 01-04 up to 2023-327 (PJ56 + 1 day) the DESPUN_SC_TO_J2000 and
SC_VEL_ANGULAR_J2000XYZ objects have inaccurate records occasionally, roughly
one record affected per day (but occasionally more) per data product. This has
been fixed in files from 2023-328 and onward, and for any future Versions, but
remains in previous files.
DESPUN_SC_TO_J2000 is a critical transformation matrix if you want to convert
from the despun spacecraft coordinates to J2000, then on the JSS, e.g. for
moments calculations or pitch angles.
The issue was a tolerance setting in the SPICE command ckgpav (which returns
both the DESPUN_SC_TO_J2000 and SC_VEL_ANGULAR_J2000XYZ values). From previous
missions, we set a tolerance, and had been set to the equivalent of one Juno
spin (30s). However Juno has continuous ck kernels and we should have set the
tolerance to zero (and now have for all data since 2023-328). Practically this
should make no difference, we ask for a time and the ckgpav command is
expected to return the values exactly at that time due to the continuous ck
kernels. And this is usually what happens.
In the SPICE ckgpav documentation we found the warning:
"In general, because using a non-zero tolerance affects selection of the
segment from which the data is obtained, users are strongly discouraged from
using a non-zero tolerance when reading CKs with continuous data."
It seems that if the time we request is near a segment boundary (in the CK
file) to within the non-zero tolerance, it can return values within the
tolerance, but not at the exact time we asked, essentially flat-lining the
output for the duration of the tolerance (30s in our case). i.e. despite Juno
spinning, the returned output would fix the orientation for 30s.
This was found from numerical moments for an hour that were of corotating
plasma, but one moment was anticorotational, despite the plasma clearly being
stable for the whole period. While the moments in the spacecraft frame were
consistent for all, it was realized one record had a drastically different
DESPUN_SC_TO_J2000 matrix than all its neighbors, thus this incorrect
orientation implied an anticorotational flow.
For an example, see the record at 2017-038T07:32:11.857 in file
JAD_L30_LRS_ION_ANY_CNT_2017038_V04.DAT
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