PDS_VERSION_ID = PDS3
RECORD_TYPE = FIXED_LENGTH
RECORD_BYTES = 352
FILE_RECORDS = 18651
^TABLE = "JPAMERG2.TAB"
DATA_SET_ID = "GIO-C-JPA-4-DDR-HALLEY-MERGE-V1.0"
TARGET_NAME = HALLEY
START_TIME = 1986-03-12T06:09:30.000
DESCRIPTION = "This table contains results from the Fast Ion Sensor (FIS)
of the Three-Dimensional Particle Analyser experiment on
the GIOTTO spacecraft for the mission to comet
P/Halley. The results from the FIS have been merged with results from the
magnetometer, the RPA-Copernic plasma experiment, and the Ion Mass
Spectrometer (IMS) HERS instrument to form this file. No editing or
reformatting has been performed.
The following is reproduced from the documentation by Marcia Neugebauer
(with some input to this document from A.Coates, K.H. Glassmeier, H. Reme)
provided with the original GIOMERGE data file, now called JPAMERG2:
GIOMERGE Version 1.2
This is the documentation which accopmanies GIOMERGE, a file which contains
merged selected processed MAG, JPA, RPA and IMS/HERS data of observations
made onboard Giotto during its flyby of comet P/Halley.
The file contains data for the following intervals and experiments:
MAG March 12, 06:09:30 - March 13, 23:36:34 SCET
8s averaged data
RPA March 12, 05:06:50 - March 13, 23:36:34 SCET
8s averaged data
JPA March 12, 06:09:30 - March 13. 22:38:16 SCET
8s data up to March 13, 19:24:55, 24s after this time
IMS/HERS March 12, 06:09:30 - March 13, 23:36:34 SCET
16s proton samples after March 13, 18:30:00
64s averaged alpha data
MAG and RPA data are available for all of the above given intervals.
There are some differences in the timing and values shown in the JPAMERGE
file for the MAG data as shown in the following table:
Mag values JPA values Times Data gap filling
JPAMERG1 = = 0 None
JPAMERG2 Not = = -4.46s -999.9
MAG00001 = N/A +0.36s -999.9
The timing differences in the JPA data occur for 3 reasons:
(1) Use of beginning of bin or middle of bin
(2) Internal buffering of 0.5 sec in JPA
(3) Crossing time of the solar wind across the FIS field of view,
which occurs 0.25 sec after the beginning of a bin
The correct JPA times for a middle of bin could be retrieved by adding
3.75s to the times in JPAMERG1.
In the existing files:
- MAG data are averages at the middle of the time bin given in all
cases, which explains the difference in values (not noticeable
on a plot) in JPAMERG2. However the reason for the time
difference between JPAMERG1 and MAG00001 is unclear, it may be
an attempt to correct for the actual time of the solar wind
entering the FIS field of view.
- JPA data are beginning of bin in file JPAMERG1. In JPAMERG2
attempts were made to make the data middle of bin but
unfortunately 3.75s should have been added to the data as
mentioned above. This mistake could have occurred during
addition of data at other institutes.
Therefore, treat times as accurate to +/- 4s.
JPA FIS data are from two sources:
- up to March 13, 19:24:55 SCET, data are from the solar wind mode at 8
seconds time resolution. The moments are derived from data in a
45 x 45 degree field of view, centered on the nominal solar wind
direction. There is continuous coverage in energy and angle. The
peak remains within this reduced field of view. JPA alpha data
should not be used after 18:25 on day 72.
- March 13, 19:24:55 to 22:38:17 SCET, data are from the HAR mode at 24
second time resolution. This mode has an angular field of view
accepting ions from all directions except a 20 deg cone in the ram
direction. Energy-angle coverage is not contiguous in this mode so
an assumption is made to boost the counts in each bin to make the
distribution appear contiguous. The peak of the solar wind flux
alternates between the last two 26 deg bins during this period.
Moments are calculated for the regions of space sampled by the
detector, i.e. up to the 20 deg ram cone, with no assumption to increase
the range beyond this. After 19:24:55 on the inbound pass when the
HAR mode data are used, the values given should be divided by 3.2 to
account of the bin sizes for HAR (Coates, et al. (1990).
The temperature profile from solar winds to HAR mode is not continuous due
to the different bin sizes involved, so the sudden temperature jump at
19:24:55 should not be taken to be correct.
IMS proton and alpha data have been processed differently:
- Proton data were obtained during ~1 s intervals every 16 s. Since the
measurement intervals happened to fall approximately midway between
the 8 s times at which the other data in this file are given, each
proton parameter is given twice -- ~4 s before the measurement and
~4 s after the measruement was made. Up until ~1830 on March 13, the
solar wind was close to or slightly beyond the proton field of view
of the HERS so V[z] could not be determined. We recommend using JPA
proton data for this time interval, and so have not included IMS
proton data in the merged file for this early period.
- Alpha data were also obtained during ~1 s intervals every 16 s, but
the parameters have been calculated for averages over 4 such measure-
ments; each value is therefore repeated 8 times in this data file.
As data from all four experiments were not available for the entire time
interval missing datasets have been replaced by zeroes. However, data
gaps are indicated by -999.99"
RECORD_FORMAT = "F14.8, 28(E12.4)"
OBJECT = TABLE
NAME = "JPAMERG2_TABLE"
INTERCHANGE_FORMAT = ASCII
COLUMNS = 29
ROW_BYTES = 352
ROWS = 18651
DESCRIPTION = "This table contains results from the JPA FIS, MAG,
RPA and IMS experiments."
OBJECT = COLUMN
NAME = SC_EVENT_TIME
BYTES = 14
DATA_TYPE = ASCII_REAL
START_BYTE = 1
FORMAT = "F14.8"
UNIT = "MJD"
DESCRIPTION = "Spacecraft event time expressed as modified Julian date,
where 13220 is 13 March 1986."
END_OBJECT
OBJECT = COLUMN
NAME = PROTON_VX
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 15
FORMAT = "E12.4"
UNIT = "KM/S"
DESCRIPTION = "Proton X velocity component, HSE coordinate system"
END_OBJECT
OBJECT = COLUMN
NAME = PROTON_VY
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 27
FORMAT = "E12.4"
UNIT = "KM/S"
DESCRIPTION = "Proton Y velocity component, HSE coordinate system"
END_OBJECT
OBJECT = COLUMN
NAME = PROTON_VZ
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 39
UNIT = "KM/S"
FORMAT = "E12.4"
DESCRIPTION = "Proton Z velocity component, HSE coordinate system"
END_OBJECT
OBJECT = COLUMN
NAME = PROTON_NUMBER_DENSITY
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 51
FORMAT = "E12.4"
UNIT = "CM**-3"
DESCRIPTION = "Number density of protons"
END_OBJECT
OBJECT = COLUMN
NAME = PROTON_TEMPERATURE
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 63
FORMAT = "E12.4"
UNIT = "KELVIN"
DESCRIPTION = "Temperature of the protons, in Kelvin"
END_OBJECT
OBJECT = COLUMN
NAME = ALPHA_VX
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 75
FORMAT = "E12.4"
UNIT = "KM/S"
DESCRIPTION = "Alpha particle X velocity component, HSE coordinate system"
END_OBJECT
OBJECT = COLUMN
NAME = ALPHA_VY
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 87
FORMAT = "E12.4"
UNIT = "KM/S"
DESCRIPTION = "Alpha particle Y velocity component, HSE coordinate system"
END_OBJECT
OBJECT = COLUMN
NAME = ALPHA_VZ
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 99
UNIT = "KM/S"
FORMAT = "E12.4"
DESCRIPTION = "Alpha particle Z velocity component, HSE coordinate system"
END_OBJECT
OBJECT = COLUMN
NAME = ALPHA_NUMBER_DENSITY
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 111
FORMAT = "E12.4"
UNIT = "CM**-3"
DESCRIPTION = "Number density of alpha particles"
END_OBJECT
OBJECT = COLUMN
NAME = ALPHA_TEMPERATURE
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 123
FORMAT = "E12.4"
UNIT = "KELVIN"
DESCRIPTION = "Temperature of the alpha particles, in Kelvin"
END_OBJECT
OBJECT = COLUMN
NAME = B_X
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 135
FORMAT = "E12.4"
UNIT = "NANOTESLA"
DESCRIPTION = "X component of magnetic field, HSE coordinate system"
END_OBJECT
OBJECT = COLUMN
NAME = B_Y
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 147
FORMAT = "E12.4"
UNIT = "NANOTESLA"
DESCRIPTION = "Y component of magnetic field, HSE coordinate system"
END_OBJECT
OBJECT = COLUMN
NAME = B_Z
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 159
FORMAT = "E12.4"
UNIT = "NANOTESLA"
DESCRIPTION = "Z component of magnetic field, HSE coordinate system"
END_OBJECT
OBJECT = COLUMN
NAME = ELECTRON_DENSITY
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 171
FORMAT = "E12.4"
UNIT = "CM**-3"
DESCRIPTION = "Number density of electrons"
END_OBJECT
OBJECT = COLUMN
NAME = AVG_ENERGY
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 183
FORMAT = "E12.4"
UNIT = "ELECTRON VOLTS"
DESCRIPTION = "Averaged electron energy"
END_OBJECT
OBJECT = COLUMN
NAME = Q_OUT
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 195
FORMAT = "E12.4"
UNIT = "ERG/( (CM**2) SEC)"
DESCRIPTION = "Heat flux away from the Sun"
END_OBJECT
OBJECT = COLUMN
NAME = Q_IN
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 207
FORMAT = "E12.4"
UNIT = "ERG/( (CM**2) SEC)"
DESCRIPTION = "Heat flus toward the Sun"
END_OBJECT
OBJECT = COLUMN
NAME = "Q_MIN/Q_MAX"
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 219
FORMAT = "E12.4"
DESCRIPTION = "Minimum Q divided by maximum Q"
END_OBJECT
OBJECT = COLUMN
NAME = IMS_PROTONS_VX
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 231
FORMAT = "E12.4"
UNIT = "KM/S"
DESCRIPTION = "Proton X velocity component in the HSE coordinate
system, as derived from the IMS/HERS measurements"
END_OBJECT
OBJECT = COLUMN
NAME = IMS_PROTONS_VY
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 243
FORMAT = "E12.4"
UNIT = "KM/S"
DESCRIPTION = "Proton Y velocity component in the HSE coordinate
system, as derived from the IMS/HERS measurements"
END_OBJECT
OBJECT = COLUMN
NAME = IMS_PROTONS_VZ
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 255
FORMAT = "E12.4"
UNIT = "KM/S"
DESCRIPTION = "Proton Z velocity component in the HSE coordinate
system, as derived from the IMS/HERS measurements"
END_OBJECT
OBJECT = COLUMN
NAME = IMS_PROTON_DENSITY
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 267
FORMAT = "E12.4"
UNIT = "CM**-3"
DESCRIPTION = "Number density of protons derived from the IMS/HERS
measurements"
END_OBJECT
OBJECT = COLUMN
NAME = IMS_PROTON_TEMPERATURE
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 279
FORMAT = "E12.4"
UNIT = "KELVIN"
DESCRIPTION = "Proton temperature derived from the IMS/HERS
measurements"
END_OBJECT
OBJECT = COLUMN
NAME = IMS_ALPHA_VX
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 291
FORMAT = "E12.4"
UNIT = "KM/S"
DESCRIPTION = "Alpha particle X velocity component in the HSE
coordinate system, as derived from the IMS/HERS
measurements"
END_OBJECT
OBJECT = COLUMN
NAME = IMS_ALPHA_VY
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 303
FORMAT = "E12.4"
UNIT = "KM/S"
DESCRIPTION = "Alpha particle Y velocity component in the HSE
coordinate system, as derived from the IMS/HERS
measurements"
END_OBJECT
OBJECT = COLUMN
NAME = IMS_ALPHS_VZ
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 315
FORMAT = "E12.4"
UNIT = "KM/S"
DESCRIPTION = "Alpha particle Z velocity component in the HSE
coordinate system, as derived from the IMS/HERS
measurements"
END_OBJECT
OBJECT = COLUMN
NAME = IMS_ALPHA_DENSITY
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 327
FORMAT = "E12.4"
UNIT = "CM**-3"
DESCRIPTION = "Number density of Alpha particles as derived from
IMS/HERS measurements"
END_OBJECT
OBJECT = COLUMN
NAME = IMS_ALPHA_TEMPERATURE
BYTES = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 339
FORMAT = "E12.4"
UNIT = "KELVIN"
DESCRIPTION = "Temperature of the alpha particles as derived from
IMS/HERS measurements"
END_OBJECT
END_OBJECT = TABLE /* JPAMERG2_TABLE */
END