This lists the particular calibration files used for each record of JADE data, all of which may be found in the same directory as this file. The Level 3 files created here came from Level 2 Version 01 files only. The level 3 data records themselves have five objects that provide useful information: - SOURCE_BACKGROUND Value of 0 to 255, where 0 = no background was removed. [See the LBL file corresponding to the data product for information on what other values mean. (Use the LBL file from the DAT day in question.) ] - SOURCE_DEAD_TIME Value of 0 to 255, where 0 = no dead-time correction has been applied. [See the LBL file corresponding to the data product for information on what other values mean. (Use the LBL file from the DAT day in question.) ] - SOURCE_MAG Value of 0 to 255, where: 0 = None: No MAG data in this JADE product 1 = From Juno JADE's Level 2 files. (From spacecraft and therefore uncalibrated.) Independent to JADE Level 2 version number. ** See below for the rest of this long entry in its own section. ** [See the LBL file corresponding to the data product for information on what other values mean. (Use the LBL file from the DAT day in question.) ] - SOURCE_JADE_METAKERNEL Value of 0 to 32767 This is the version number (nnnnn) of the JADE SPICE metakernel used for a given record of JADE DATA in this PDS volume. The appropriate file is then: JAD_L30_SPICE_METAKERNEL_nnnnn - SOURCE_JADE_CALIB Value of 0 to 32767 This is the version number (nnnnn) of the JADE calibration list used for a given record of JADE DATA in this PDS volume. The appropriate file is then: JAD_L30_CALIB_LIST_nnnnn [This file is JAD_L30_CALIB_LIST_00001] ------------------------------------------------------------------------------ Converting MCP voltages to volts This is a simple equation for each JADE sensor, going from the Level 2 MCP_COMMANDED_VALUE object to the Level 3 MCP_VOLTAGE object. If L2.MCP_COMMANDED_VALUE = 0 { L3.MCP_VOLTAGE = 0 } ELSE { L3.MCP_VOLTAGE = m * L2.MCP_COMMANDED_VALUE + c } where values for m and c are: JADE-E060: m = +0.9271, c = +18.542 JADE-E180: m = +0.9306, c = +18.210 JADE-E300: m = +0.9302, c = +17.853 JADE-I : m = -0.9277, c = -20.213 The JADE-I vales are negative, JADE-E ones positive. ------------------------------------------------------------------------------ For DATA level 3 objects See the SIS document for the complete chain of alterations between Level 2's DATA object to that of Level 3's DATA object. Part of that chain is dealing with the onboard lossy compression of data that is Look Up Table (LUT) dependent. The Level 2 files have a TABLES_VERSION object that lists the particular LUT used per record, which is a float to two decimal places. e.g. LUT 3.06 is TABLES_VERSION = 3.06 or perhaps 3.059999999 as it is a float. TABLES_VERSION m.nn compression LUTS and associated values are found in the CALIB directory files of the name LUT_m_nn_COMPRESSION, e.g. for TABLES_VERSION = 3.06 it would be file LUT_3_06_COMPRESSION.CSV The DATA_SIGMA (uncertainty in DATA) object is a complicated item to calculate that is dependent on product type, and potentially spin-period and the start spin-phase of each record. For this iteration of data, the methods within the file DATA_UNCERTAINTY_EQNS_V01.PDF were used. ------------------------------------------------------------------------------ For DIM1_E level 3 objects Just as with the DATA object in the previous section, the energy tables are also stored as LUTs, and require the TABLES_VERSION object to know while file to use for a given record; those files are in files LUT_m_nn_ENERGY_Vvv.CSV. This iteration uses version 01 files (e.g. LUT_m_nn_ENERGY_V01.CSV). The file contains many columns as each JADE sensor has multiple sweep profiles, JADE-I has 4 sweep tables, JADE-Es have 3. The particular table used for each record is listed in the level 2 SWEEP_TABLE object. ------------------------------------------------------------------------------ For DIM2_* level 3 objects The field of view values are found from a combination of information of where the sensors are bolted to the spacecraft, the way data is taken/stored by the instrument for a given product, whether the electron deflectors are on or not, and utilizes SPICE for general Juno position/orientation/velocity. The particular SPICE metakernel used (which nnnnn) is given in every Level 3 record (see the introduction section to this file) and the file is in the CALIB directory with the filename format JAD_L30_SPICE_METAKERNEL_nnnnn.TXT. For the field of view DIM2_* level 3 objects for JADE-I and JADE-E's, respectively, the following files were used for all but `electron high rate science' at Jupiter: ANODE_LOOK_ION_DEFL_NONE_V02 ANODE_LOOK_ELC_DEFL_NONE_V02 The 'electron high rate science' product (the only product with deflectors on when at Jupiter) used files: ANODE_LOOK_ELC_DEFL_EQNS_V01 for elevations of version 01 data files only ANODE_LOOK_ELC_DEFL_EQNS_V02 for elevations of version 02 data files only ANODE_LOOK_ELC_DEFL_NONE_V02 for all azimuths (as unaffected by deflection) [Note 1: We start with version 2 for the NONE deflection cases (but EQNS is version 01) as version 1 had a mistake, realized prior to PDS data submission. Version 1 assumed that each anode had a fixed azimuth width in the s/c frame, which means that the stated field of view actually gets narrower at higher elevations. In version 2 each anode has the azimuth angle adjusted to be the same angular width, which means that the azimuthal range gets larger for higher elevations. However plotting them on a sphere does indeed show that they all align.] [Note 2: During cruise, the high rate science electrons had deflectors off and the ANODE_LOOK_ELC_DEFL_NONE_V01 file was used for version 01 data, and the ANODE_LOOK_ELC_DEFL_NONE_V02 file was used for version 02 data (but those csv files are identical). The first use of deflectors for science was not until PJ1, 2016-240. (Deflectors were used during cruise periods for some operational tests, but those intervals are not science quality and should not be used.)] ------------------------------------------------------------------------------ For DIM3_* level 3 objects (TOF only) The file TOF_CHANNEL_TO_SECONDS_HLC_V01 contains 5 columns: INDEX, TOF_CH_LOWER, TOF_CH_UPPER, TOF_SECONDS_LOWER, TOF_SECONDS_UPPER The (IDL) equations to go from TOF_CH_LOWER and TOF_CH_UPPER to actual seconds (TOF_SECONDS_LOWER and TOF_SECONDS_UPPER) are (with comments starting with #): # 1.6 nano-seconds per TOF_CH, in IDL speak 1.6e-9 seconds TOF_CH_START = FLOAT(TOF_CH_LOWER ) * 1.6e-9 ; convert to seconds TOF_CH_END = FLOAT(TOF_CH_UPPER + 1) * 1.6e-9 ; convert to seconds # step through all records in the file and write out TOF_CH_START/END # n is number of records, so IDL index range is 0:(n-1), # 0L and 1L are 0 and 1 as long integers FOR z=0L,(n-1L) DO L3.DIM3_TOF_LOWER[z,0:92] = TOF_CH_START FOR z=0L,(n-1L) DO L3.DIM3_TOF_UPPER[z,0:92] = TOF_CH_END L3.DIM3_TOF = (L3.DIM3_TOF_LOWER + L3.DIM3_TOF_UPPER) / 2.0 ------------------------------------------------------------------------------ SOURCE_MAG object in Level 3 files. The MAG data used in JADE files can come from a variety of sources; onboard, FGM Level 2 or FGM Level 3. (FGM (instrument code) and MAG are use interchangeably in this document.) SOURCE_MAG is a value from 0 to 255, and at time of writing the mapping is given in the LBL/FMT files as: Source of MAG data Except case 0 and 1, PAYLOAD (pl) co-ordinate MAG files were used at 1s (or 2s if no 1s) resolution. 0 = None: No MAG data in this product. 1 = From Juno JADE's Level 2 files. (From spacecraft and therefore uncalibrated.) This is independent to JADE Level 2 version number as it does not change with versions. [Note MAG data in JADE files may be affected by the Juno time stutter.] 3n = Juno's MAG's Level 3 version n calibrated files, e.g. 34 means version 4, so: 30 = From Juno MAG's Level 3 version 00 quicklook payload files. (These are temporary files not in PDS.) 31 = From Juno MAG's Level 3 version 01 calibrated payload files. 32 = From Juno MAG's Level 3 version 02 calibrated payload files. Likewise 33 to 39 being Level 3 version 3 to 9. 255 = Unknown. If you see a number not listed above, there may be later versions of MAG data - find the latest available LBL file for this product and see what that has listed. ------------------------------------------------------------------------------ Despin MAG_VECTOR (Electron files only) JADE Level 2 electron files have a MAG vector within them in spacecraft co-ordinates, ion data do not (so do not have an included MAG_VECTOR object). For electron data, use the MAG_TIMESTAMP_WHOLE:MAG_TIMESTAMP_SUB spacecraft clock timestamp from level 2 files to find the spin phase (sp) at that instant, and rotate MAG_VECTOR x and y components accordingly (the z component does not change). For HRS level 2 files there is no MAG_TIMESTAMP_SUB object, so it is assumed to MAG_TIMESTAMP_SUB = 00000, meaning the spin phase angle can be off by up to ~12 degrees (based on a perfect 30s spin period). The equations used are simply: L3.MAG_VECTOR_X = L2.MAG_VECTOR_X*COS(sp) - L2.MAG_VECTOR_Y*SIN(sp) L3.MAG_VECTOR_Y = L2.MAG_VECTOR_X*SIN(sp) + L2.MAG_VECTOR_Y*COS(sp) L3.MAG_VECTOR_Z = L2.MAG_VECTOR_Z Note that this level 2 MAG_VECTOR is only returned if the onboard magnetic magnitude is greater than 200 nT, otherwise MISSING_CONSTANT is returned. As such, only close passes met this criteria; outer/middle magnetosphere and cruise data in the solar wind do not have this value populated. ------------------------------------------------------------------------------ Data Unit Conversion Conversion of Level 2 data units (counts per accumulation or counts per view) to Level 3 data units of counts per second is described in the JADE SIS, section: `6.2.9.4.9 Convert Data and uncertainties to counts per second.' ------------------------------------------------------------------------------