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