FIRAS Explanatory Supplement Appendix H

                 Record Definition Language Files (RDLs) for
                     FIRAS Native VAX Binary Format Files

This appendix contains Record Definition Language Files (RDLs) for the following
FIRAS native VAX binary format files:

Sky Data Index:
    FSS_SSSKY_RH, FSS_SSSKY_RL, FSS_SSSKY_LH, FSS_SSSKY_LL
Calibration Data Index:
    FEC_SSCAL_RH, FEC_SSCAL_RL, FEC_SSCAL_LH, FEC_SSCAL_LL
Time-Ordered Interferogram:
    FDQ_SDF_RH, FDQ_SDF_RL, FDQ_SDF_LH, FDQ_SDF_LL
Engineering Data:
    FDQ_ENG
Housekeeping Data:
    NFS_HKP
Ancillary Housekeeping Data:
    NFS_ANC
Engineering Mode Timing Data:
    NFS_EMF_RH, NFS_EMF_RL, NFS_EMF_LH, NFS_EMF_LL
Reference Datasets:
    FEX_DTRF.DAT
    FEX_GLTCHPRO.DAT
    FEX_BASIS.DAT

--------------------------------------------------------------------------------

!
! FIRAS Sky Data Short Science Index Record.
!
Record FSS_SSSKY FSS_SSSKY

  scalar/adt                    TIME
                                ! Raw Science IFG GMT
  scalar/byte                   CHANNEL_ID
                                ! Channel ID
  scalar/long                   PIXEL_NO
                                ! Pixel Number
  scalar/byte                   MTM_SCAN_SPEED
                                ! MTM Speed
  scalar/byte                   MTM_SCAN_LENGTH
                                ! MTM Length
  scalar/byte                   SCI_MODE
  scalar/byte                   ADDS_PER_GROUP
                                ! Adds Per Group
  scalar/byte                   TRANSITION_FLAG
                                ! Flag denoting group
                                !   of coaddable raw
                                !   science IFGs
  scalar/text/length=1          PIXEL_DEFINITION
                                ! Type of pixelization:
                                !   'q' = standard quad-cube
                                !   'O' = orbit average
                                !   'S' = scan angle
                                !   'E' = geocentric
                                !         quad-cube
  scalar/word                   SKYMAP_INDEX
                                ! Information supporting
                                ! PIXEL_DEFINITION:
                                !
                                !  Type    SKYMAP_INDEX Content
                                !    q      standard quad-cube
                                !           skymap index
                                !    O      orbit origin
                                !          (units = 0.1d)
                                !    S      scan angle
                                !          (units = 0.1d)
                                !    E      skymap index
  scalar/byte                   DATA_QUALITY
                                ! Summary Flag for Instruments
  scalar/byte                   ATTITUDE_QUALITY
                                ! Summary Flag for Attitude
  scalar/float                  XCAL_TEMP
                                ! External Calibrator Temperature
  scalar/float                  SKYHORN_TEMP
                                ! Skyhorn Temperature
  scalar/float                  REFHORN_TEMP
                                ! Reference Horn Temperature
  scalar/float                  ICAL_TEMP
                                ! Internal Calibrator Temperature
  scalar/float                  DIHEDRAL_TEMP
                                ! Dihedral Temperature
  scalar/float                  BOLOMETER_TEMP
                                ! Detector Temperature
  scalar/byte                   BOL_CMD_BIAS
                                ! Commanded Bias
  scalar/word                   EXC_GALACTIC_LAT
                                ! Exclude data within +/- 
                                ! Galactic Latitude
                                !   Range: 0 to +Pi/2
                                !   Units: 10**-4 radians
  scalar/word                   SUN_ANGLE
                                ! Angle of sun from FIRAS
                                ! skyhorn Line-of-sight
                                !   Range: 0 to Pi
                                !   Units: 10**-4 radians
  scalar/word                   MOON_ANGLE
                                ! Angle of moon from FIRAS
                                ! skyhorn Line-of-sight
                                !   Range: 0 to Pi
                                !   Units: 10**-4 radians
  scalar/word                   EARTH_LIMB
                                ! Angle of Earth limb from
                                ! FIRAS skyhorn Line-of-sight
                                !   Range: 0 to Pi
                                !   Units: 10**-4 radians
  scalar/word                   GALACTIC_LATITUDE
                                ! Galactic Latitude
                                !   Range: -Pi/2 to +Pi/2
                                !   Units: 10**-4 radians
  array/byte/dim=6              SPARES
                                ! Spares
end_record

--------------------------------------------------------------------------------

!
! FIRAS Calibration Data Short Science Index Record.
!
Record FSS_SSCAL FSS_SSCAL

  scalar/adt                    TIME
                                ! Raw Science IFG GMT
  scalar/byte                   CHANNEL_ID
                                ! Channel ID
  scalar/long                   PIXEL_NO
                                ! Pixel Number
  scalar/byte                   MTM_SCAN_SPEED
                                ! MTM Speed
  scalar/byte                   MTM_SCAN_LENGTH
                                ! MTM Length
  scalar/byte                   SCI_MODE
  scalar/byte                   ADDS_PER_GROUP
                                ! Adds Per Group
  scalar/byte                   TRANSITION_FLAG
                                ! Flag denoting group
                                !   of coaddable raw
                                !   science IFGs
  scalar/text/length=1          PIXEL_DEFINITION
                                ! Type of pixelization:
                                !   'q' = standard quad-cube
                                !   'O' = orbit average
                                !   'S' = scan angle
                                !   'E' = geocentric
                                !         quad-cube
  scalar/word                   SKYMAP_INDEX
                                ! Information supporting
                                ! PIXEL_DEFINITION:
                                !
                                !  Type    SKYMAP_INDEX Content
                                !    q      standard quad-cube
                                !           skymap index
                                !    O      orbit origin
                                !          (units = 0.1d)
                                !    S      scan angle
                                !          (units = 0.1d)
                                !    E      skymap index
  scalar/byte                   DATA_QUALITY
                                ! Summary Flag for Instruments
  scalar/byte                   ATTITUDE_QUALITY
                                ! Summary Flag for Attitude
  scalar/float                  XCAL_TEMP
                                ! External Calibrator Temperature
  scalar/float                  SKYHORN_TEMP
                                ! Skyhorn Temperature
  scalar/float                  REFHORN_TEMP
                                ! Reference Horn Temperature
  scalar/float                  ICAL_TEMP
                                ! Internal Calibrator Temperature
  scalar/float                  DIHEDRAL_TEMP
                                ! Dihedral Temperature
  scalar/float                  BOLOMETER_TEMP
                                ! Detector Temperature
  scalar/byte                   BOL_CMD_BIAS
                                ! Commanded Bias
  scalar/word                   EXC_GALACTIC_LAT
                                ! Exclude data within +/- 
                                ! Galactic Latitude
                                !   Range: 0 to +Pi/2
                                !   Units: 10**-4 radians
  scalar/word                   SUN_ANGLE
                                ! Angle of sun from FIRAS
                                ! skyhorn Line-of-sight
                                !   Range: 0 to Pi
                                !   Units: 10**-4 radians
  scalar/word                   MOON_ANGLE
                                ! Angle of moon from FIRAS
                                ! skyhorn Line-of-sight
                                !   Range: 0 to Pi
                                !   Units: 10**-4 radians
  scalar/word                   EARTH_LIMB
                                ! Angle of Earth limb from
                                ! FIRAS skyhorn Line-of-sight
                                !   Range: 0 to Pi
                                !   Units: 10**-4 radians
  scalar/word                   GALACTIC_LATITUDE
                                ! Galactic Latitude
                                !   Range: -Pi/2 to +Pi/2
                                !   Units: 10**-4 radians
  array/byte/dim=6              SPARES
                                ! Spares
end_record

--------------------------------------------------------------------------------

!
! FIRAS Time-Ordered Interferogram Record.
!
Record FDQ_SDF FDQ_SDF

  Structure CT_HEAD
!
! COBETRIEVE header for time-ordered files.
!
        scalar/text/length=14   GMT
                                !  GMT of start collect
        scalar/adt              TIME
                                !  Binary time
        array/byte/dim=6        SPACE_TIME
                                !  Spacecraft time
        scalar/long             MJR_FRM_NO
                                !  Major frame number
        scalar/long             ORBIT
                                !  Orbit number
!
! The original 28 COBETRIEVE spares are now reserved
! for the COBE subsystems. The first 20 bytes are
! reserved for use by the INGEST Subsystem.
!
        scalar/byte             HSKP1_TLM_FMT
                                !  Telemetry format for
                                !    major frame 1
        scalar/byte             HSKP2_TLM_FMT
                                !  Telemetry format for
                                !    major frame 2
        array/byte/dim=18       INGEST_SPARES
                                !  Spares
!
! The remaining 8 bytes are reserved for use by the
! instrument subsystems.
!
        scalar/word             DATASET_ID
                                !  CT dataset ID
        array/byte/dim=6        INSTR_SPARES
                                !  Spares
  EndStructure

  Structure SCI_HEAD
!
! Science data channel header written by the FIRAS stripper
!   and FIRAS Preprocessor.
!
        scalar/word             CHAN_ID
                                !  Channel id
        scalar/word             GAIN
                                !  Gain
        scalar/word             MTM_SPEED
                                !  MTM speed
        scalar/word             MTM_LENGTH
                                !  MTM scan length
        array/byte/dim=60       DATA_QUAL
                                !  Data quality flags
        array/word/dim=8        DATA_READY
                                !  Data ready flags
!
! Scan data.
!
        scalar/word             SC_HEAD0
                                !  Data block synchronization
        scalar/byte             SC_HEAD1A
                                !  Block type (sci mode)
        scalar/byte             SC_HEAD1B
                                !  Block ID
        scalar/word             SC_HEAD2
                                !  SW version number
        scalar/word             SC_HEAD3
                                !  Status bits
        scalar/word             SC_HEAD4
                                !  Transmit time LSW
        scalar/word             SC_HEAD5
                                !  Transmit time MSW
        scalar/word             SC_HEAD6
                                !  Data check
        scalar/word             SC_HEAD7
                                !  No a/d samples for collect
                                !    cycle
        scalar/word             SC_HEAD8
                                !  Points process for collect
                                !    cycle
        scalar/word             SC_HEAD9
                                !  Number of added points 1,2,
                                !   3,8,or 12 "adds per group"
        scalar/word             SC_HEAD10
                                !  Data points per mirror sweep
        scalar/word             SC_HEAD11
                                !  Number of mirror sweeps
        scalar/word             SC_HEAD12
                                !  LSW frame counter
        scalar/word             SC_HEAD13
                                !  MSW frame counter
        scalar/word             SC_HEAD14
                                !  Deglitcher threshold factor
        scalar/word             SC_HEAD15
                                !  Noise level
        scalar/word             SC_HEAD16
                                !  S/L counter constants
        scalar/word             SC_HEAD17
                                !  Deglitcher Seed Sample
        scalar/word             SC_HEAD18
                                !  Command Counter
        scalar/word             SC_HEAD19
                                !  Program Checksum
        scalar/word             SC_HEAD20
                                !  Saturated Sample Count
        scalar/word             SC_HEAD21
                                !  Glitch total
        scalar/word             SC_HEAD22
                                !  Deglitcher overflow address
        scalar/word             SC_HEAD23
                                !  Division of IFG performed
                                !    (FCI RMS files only)
        scalar/word             SC_HEAD24
                                !  FCI raw science intermediate
                                !    dump data type
        scalar/word             SC_HEAD25
                                !  High/low channel indicator
                                !    'HI' = high
                                !    'LO' = low
  EndStructure

  Structure IFG_DATA
!
! Raw science data.
!
        array/word/dim=512      IFG
                                !  IFG in counts
        array/word/dim=32       GLTCH
                                !  On board glitch map
  EndStructure

  Structure DQ_DATA
!
! Fields written by Data Qualify.
!
        scalar/word             FAKE
                                !  Fakeit pulse status
        scalar/word             XCAL_POS
                                !  Position of xcal 0
        scalar/float            IREF_TEMP
                                !  Internal reference source
                                !    temperature
				!  This value is no longer being calaulated
				!  by FDQ
        scalar/adt              ENG_TIME
                                !  Time of associate
                                !    engineeering record
        scalar/long             ENG_REC
                                !  Engineering record number
        array/byte/dim=110      DATA_QUALITY
                                !  Data quality flags
        scalar/long             IFG_NO
                                !  IFG number within segment
        array/byte/dim=24       DQ_SPARES
                                !  Data qualify spares
  EndStructure

  Structure COLLECT_TIME
!
! Fields written by the FIRAS Preprocessor.
!
        scalar/adt              MIDPOINT_TIME
                                !  Midpoint of Collect Time 
                                !    for science IFG
        scalar/byte             BADTIME_FLAG
                                !  Flag for invalid computed 
                                !    midpoint of collect time
        scalar/byte             FPP_SPARE
                                !  Preprocessor spare
  EndStructure

  Structure ATTITUDE
!
! Attitude related quantities.
! All quantities are in Epoch 2000.0 coordinates.
!
        scalar/long             PIXEL_NO
                                !  FIRAS pixel number
        array/float/dim=3       EQUATORIAL
                                !  FIRAS pointing in
                                !  celestial equatorial
                                !  coordinates
                                !    Unit vectors
        scalar/word             RA
                                !  Right ascension of
                                !  FIRAS pointing
                                !    Range: - Pi to + Pi
                                !    Units: 10**-4 radians
        scalar/word             DEC
                                !  Declination of FIRAS
                                !  pointing
                                !    Range: - Pi/2 to + Pi/2
                                !    Units: 10**-4 radians
        scalar/long             TERR_PIXEL_NO
                                !  Terrestrial coordinates
                                !  based pixel number
        scalar/word             TERR_LATITUDE
                                !  Terrestrial latitude of
                                !  COBE
                                !    Range: - Pi/2 to + Pi/2
                                !    Units: 10**-4 radians
        scalar/word             TERR_LONGITUDE
                                !  Terrestrial longitude of
                                !  COBE
                                !    Range: - Pi to + Pi
                                !    Units: 10**-4 radians
        scalar/word             EARTH_LIMB
                                !  Angle of Earth limb from
                                !  FIRAS skyhorn Line-of-Sight
                                !    Range: 0 to Pi
                                !    Units: 10**-4 radians
        scalar/word             EARTH_LIMB_AZIMUTH
                                !  Azimuth angle of Earth limb
                                !  about FIRAS LOS in SC frame
                                !    Range: - Pi to + Pi
                                !    Units: 10**-4 radians
        scalar/word             SUN_ANGLE
                                !  Angle of Sun in FIRAS
                                !  skyhorn LOS
                                !    Range: 0 to Pi
                                !    Units: 10**-4 radians
        scalar/word             MOON_ANGLE
                                !  Angle of Moon in FIRAS
                                !  skyhorn LOS (phi)
                                !    Range: 0 to Pi
                                !    Units: 10**-4 radians
        scalar/word             MOON_AZ_ANGLE
                                !  Azimuth angle of Moon about
                                !  FIRAS LOS in SC frame
                                !  (theta)
                                !    Range: - Pi to + Pi
                                !    Units: 10**-4 radians
        scalar/word             MOON_PHASE
                                !  Phase of Moon
                                !    Range: - Pi to + Pi
                                !    Units: 10**-4 radians
        scalar/float            SUN_MOON_DIST
                                !  Sun-Moon distance
                                !    Units: km
        scalar/float            COBE_MOON_DIST
                                !  COBE-Moon distance
                                !    Units: km
        scalar/word             ALTITUDE
                                !  COBE altitude
                                !    Units: 0.1 km
        scalar/word             PROJECTED_BARYCENTRIC_VELOCITY
                                !  Solar system barycentric vel
                                !  of COBE projected along LOS
                                !    Units: 0.01 km/sec
        scalar/word             MCILWAIN_L_PARAM
                                !  McIlwain L parameter
                                !    Units: Earth radii
        scalar/word             GALACTIC_LONGITUDE
                                !  Galactic longitude
                                !    Range: - Pi to + Pi
                                !    Units: 10**-4 radians
        scalar/word             GALACTIC_LATITUDE
                                !  Galactic latitude
                                !    Range: - Pi/2 to + Pi/2
                                !    Units: 10**-4 radians
        scalar/word             ECLIPTIC_LONGITUDE
                                !  Ecliptic longitude
                                !    Range: - Pi to + Pi
                                !    Units: 10**-4 radians
        scalar/word             ECLIPTIC_LATITUDE
                                !  Ecliptic latitude
                                !    Range: - Pi/2 to + Pi/2
                                !    Units: 10**-4 radians
        scalar/word             ORBITAL_PHASE
                                !  Geocentric angle from
                                !  the orbital ascending
                                !  node to COBE position
                                !    Range: - Pi to + Pi
                                !    Units: 10**-4 radians
        scalar/word             PROJECTED_GEOCENTRIC_VELOCITY
                                !  Geocentric velocity of
                                !  COBE projected along LOS
                                !    Units: 0.001 km/sec =
                                !                  m/sec
        scalar/word             SCAN_ANGLE
                                !  Azimuth angle, about the
                                !  Sun direction, of FIRAS
                                !  LOS, positive in the
                                !  ascending sense from the
                                !  ecliptic
                                !    Range: - Pi to + Pi
                                !    Units: 10**-4 radians
        scalar/word             SC_ROTATION_ANGLE
                                !  Spaceraft Rotation Angle
                                !    Range: - Pi to + Pi
                                !    Units: 10**-4 radians
        scalar/byte             SOLUTION
                                ! Source of attitude
                                ! solution
                                !   None      = 0
                                !   Simulated = 1
                                !   Predicted = 2
                                !   Coarse    = 3
                                !   Fine without Dirbe = 4
                                !   Fine with Dirbe = 5
                                !   Definitive = 6
        scalar/text/length=1    PIXEL_DEFINITION
                                ! Type of pixelization:
                                !   'q' = standard quad-cube
                                !   'O' = orbit average
                                !   'S' = scan angle
                                !   'E' = geocentric
                                !         quad-cube
        scalar/word             SKYMAP_INDEX
                                ! Information supporting
                                ! PIXEL_DEFINITION:
                                !
                                !  Type    SKYMAP_INDEX Content
                                !    q      standard quad-cube
                                !           skymap index
                                !    O      orbit origin
                                !          (units = 0.1d)
                                !    S      scan angle
                                !          (units = 0.1d)
                                !    E      skymap index
        scalar/word             EXC_GALACTIC_LAT
                                ! Exclude data within +/-
                                ! Galactic latitude
                                !   Range: 0 to +Pi/2
                                !   Units: 10**-4 radians
        scalar/byte             TERR_RAD_BYTE
                                ! Terrestrial radiation region location flag
                                ! Information only
                                ! Region determined from mission planning files
                                ! Bit 0 = OK
                                ! Bit 1 = North Van Allen Belt
                                ! Bit 2 = South Van Allen Belt
                                ! Bit 3 = South Atlantic Anomaly
                                ! Independent of attitude quality flags
        scalar/byte             OUTSIDE_GALAXY_CUT
                                ! Flag indicating whether FDS destriper
                                ! included this record in its stripe
                                ! calculation based on whether its pixel center
                                ! is outside the galactic latitude cut in the
                                ! FDS driver.  This flag is set by FAD.
                                ! 0 = not set yet (pre-FAD data)
                                ! 1 = record included (outside > galactic cut )
                                ! 2 = record excluded (within <= galactic cut )
!
! Fill the rest of the block.
!
        array/byte/dim=2        ATT_SPARES
                                !  Rest of the record
  EndStructure

End_Record

--------------------------------------------------------------------------------

Some additional notes relevant to various fields in the time-ordered
interferogram RDL are as follows.

For the science header (the SCI_HEAD structure):
    GAIN - The commandable gain for the detector is used in the  conversion of
of the IFG raw counts to volts. Valid commandable gains are 1, 3, 10, 30, 100,
300, 1000, and 3000.
    DATA_QUAL - The telemetry data quality flags consist of packed  bits, 4 for
each of the telemetry minor frames over which the IFG is transmitted. The value
of each set of four bits is a  code which represents the quality of the
telemetry as received  on the ground from the spacecraft.
    DATA_READY - The data ready flags at transmit consist of 114 packed bits,
one from each of the telemetry minor frames over which the IFG is transmitted.
A value of 1 indicates that the  corresponding section of the IFG buffer for
this channel detector was ready for transmission.  A value of 0 indicates the
existance of a problem for transmission.
    SC_HEAD1A - All of the science data was taken in science mode 4 during the
mission.  In this mode the on-board microprocessor averages the data, uses the
anti-aliasing filters, and flags the  glitches without removing them. The
removal of the glitches is  done in the ground processing by the FIRAS
pipeline.

For the IFG_DATA structure:
    IFG - The IFG in counts is an array of 512 observed points. The IFGs taken
during the mission have been averaged by the on-board microprocessors.
Depending on the MTM scan mode, a number of consecutive sample points have been
averaged to form  a group during each sweep of the mirror. The consecutive
groups  form a buffer of 512 points. In addition, a number of sweeps of  these
512 points each are coadded together to form the resulting  512 point IFG which
is then telemetered to the ground.  The SC_HEAD9 field contains the number of
sample points per group and the SC_HEAD11 field contains the number mirror
sweeps that are coadded together.
    GLTCH - The on-board glitch map is a packed array of bit flags set by the
microprocessor to a value of 1 when it detects a glitch at one of the 512 point
of the IFG. A value of 0 at the corresponding IFG position indicates no
glitches were detected at that position during the entire collection of the
IFG. The 512 bit flags are packed and stored into 32 sixteen bit words.

For the DQ_Data structure:
    FAKE - For most of the mission during the COBE passage through the South
Atlantic Anomaly, the MTM was put in a position mode, the drive motor was
turned off, and readings of a noise signal were taken using a ``fake-it''
pulse.  Noise data taken in this  mode are identified by the value of 1 in the
fake-it (FAKE) status field.
    XCAL_POS - The external calibrator position (XCAL_POS) field indicates
whether the data are sky or calibration data. A value of 1 indicates that the
XCAL is in the horn and the IFGs are thus calibration data.  A value of 2
indicates that the XCAL is completely out of the horn and the IFGs are thus sky
data.  Sky IFGs are averaged together for the same pixel, MTM scan mode, and
Ical temperature during a mission period.  Calibration IFGs are similarly
averaged over a constant temperature plateaus for the same scan mode.  Data
with any other value of the XCAL_POS are not used.
    DATA_QUALITY - The 110 data quality flags indicate whether engineering,
microprocessor, and attitude quantities associated with the IFG are within
green, yellow, or red tolerance limits.

--------------------------------------------------------------------------------

!
!  FIRAS Engineering Data Record.
!
record FDQ_ENG FDQ_ENG

  structure ct_head
!
! COBETRIEVE header for time-ordered files.
!
        scalar/text/length=14   GMT
                                !  GMT of start collect
        scalar/adt              TIME
                                !  Binary time
        array/byte/dim=6        SPACE_TIME
                                !  Spacecraft time
        scalar/long             MJR_FRM_NO
                                !  Major frame number
        scalar/long             ORBIT
                                !  Orbit number
!
! The original 28 COBETRIEVE spares are now reserved
! for the COBE subsystems. The first 20 bytes are
! reserved for use by the INGEST Subsystem.
!
        scalar/byte             HSKP1_TLM_FMT
                                !  Telemetry format for
                                !    major frame 1
        scalar/byte             HSKP2_TLM_FMT
                                !  Telemetry format for
                                !    major frame 2
        array/byte/dim=18       INGEST_SPARES
                                !  Spares
!
! The remaining 8 bytes are reserved for use by the
! instrument subsystems.
!
        scalar/word             DATASET_ID
                                !  CT dataset ID
        array/byte/dim=6        INSTR_SPARES
                                !  Spares
  endstructure

  structure en_head
!
! Engineering header.
!
        scalar/text/length=23   LIMITS
                                !  Limits file name
        scalar/text/length=23   CONVERT
                                !  Conversion file name
        scalar/long             A_SPARE
        scalar/word             KEY_ID
                                !  Type of engineering data:
                                !        0 = non-statistics
                                !        1 = average
                                !        2 = sigma
                                !        3 = minimum
                                !        4 = maximum
        scalar/long             NUMBER_OF_RECORDS
                                !  Number of engineering
                                !    records used in
                                !    forming statistics
        array/byte/dim=8        ENGHEAD_SPARES1
                                !  Spares

        structure/dim=4         SCI_TIME
           scalar/adt           BIN_TIME
                                !  Binary time
        endstructure

        scalar/adt              FIRST_ENG_TIME
                                !  Time tag of first
                                !    engineering record
                                !    used in forming
                                !    engineering trends
        scalar/adt              LAST_ENG_TIME
                                !  Time tag of last
                                !    engineering record
                                !    used in forming
                                !    engineering trends

        array/byte/dim=4        DQ_SUMMARY_FLAG
                                !  Data quality summary
                                !    flags for the four
                                !    FIRAS channels
        array/long/dim=4        IFG_NO
                                !  IFG number within
                                !    segment
        array/byte/dim=4        ATT_SUMMARY_FLAG
                                !  Attitude data quality
                                !    summary flags for the
                                !    four FIRAS channels

        array/byte/dim=34       ENGHEAD_SPARES2
                                !  Spare time bytes
  endstructure

  structure en_stat
!
! Co-added engineering status bits.
!
        union

          map
!
! Side A
!
            scalar/word        STAT_WORD_1
            scalar/word        INT_REF_TEMP_A
                               !  Internal reference source
            scalar/word        REF_HRN_TEMP_A
                               !  Reference horn
            scalar/word        STAT_WORD_4
            scalar/word        STAT_WORD_5
            scalar/word        SKY_HRN_TEMP_A
                               !  Sky horn
            scalar/word        EXT_CAL_TEMP_A
                               !  External calibrator
            scalar/word        STAT_WORD_8
!
! Side B
!
            scalar/word        STAT_WORD_9
            scalar/word        INT_REF_TEMP_B
                               !  Internal reference source
            scalar/word        REF_HRN_TEMP_B
                               !  Reference horn
            scalar/word        STAT_WORD_12
            scalar/word        STAT_WORD_13
            scalar/word        SKY_HRN_TEMP_B
                               !  Sky horn
            scalar/word        EXT_CAL_TEMP_B
                               !  External calibrator
            scalar/word        STAT_WORD_16
          endmap

          map
            array/word/dim=16  GROUP1
          endmap

        endunion
!
! Miscellaneous status words.
!
        union

          map
            array/byte/dim=2   GRT_ADDR
                               !  Dwell address A,B
            array/byte/dim=4   MICRO_STAT_BUS
                               !  Micro status bus readout
            array/byte/dim=4   BOL_CMD_BIAS
                               !  Bolometer bias
            array/byte/dim=2   DWELL_STAT
                               !  Dwell status A,B
            array/byte/dim=2   LVDT_STAT
                               !  LVDT status A,B
          endmap

          map
            array/byte/dim=14  GROUP2
          endmap

        endunion
        array/byte/dim=2       HOT_SPOT_CMD
                               !  Hot spot command for A, B side
        array/byte/dim=10      ENGSTAT_SPARES1
        array/byte/dim=2       POWER_A_STATUS
                               !  Status for power to FIRAS A
        array/byte/dim=2       POWER_B_STATUS
                               !  Status for power to FIRAS B
        array/byte/dim=6       ENGSTAT_SPARES2
  endstructure

  structure en_analog
!
! Instrument temperatures.
!
        union

          map

            array/float/dim=16      A_LO_GRT
                                    !  A side low current GRTS
            array/float/dim=16      A_HI_GRT
                                    !  A side high current GRTS
            array/float/dim=16      B_LO_GRT
                                    !  B side low current GRTS
            array/float/dim=16      B_HI_GRT
                                    !  B side high current GRTS
          endmap

          map
  
            !  A side low current GRTS
            scalar/float            A_LO_XCAL_TIP
                                    !  External calibrator tip
            scalar/float            A_LO_SKYHORN
                                    !  Sky horn
            scalar/float            A_LO_REFHORN
                                    !  Reference horn
            scalar/float            A_LO_ICAL
                                    !  Internal reference source
            scalar/float            A_LO_DIHEDRAL
                                    !  Dihedral
            array/float/dim=4       A_LO_BOL_ASSEM
                                    !  Bolometer assembly
            scalar/float            A_LO_MIRROR
                                    !  Mirror assembly
            array/float/dim=4       A_LO_CAL_RESISTORS
                                    !  Cal resistors
            scalar/float            A_LO_XCAL_CONE
                                    !  Additional xcal temp
            scalar/float            A_LO_COLLIMATOR
                                    !  Collimator
            !  A side high current GRTS
            scalar/float            A_HI_XCAL_TIP
                                    !  External calibrator tip
            scalar/float            A_HI_SKYHORN
                                    !  Sky horn
            scalar/float            A_HI_REFHORN
                                    !  Reference horn
            scalar/float            A_HI_ICAL
                                    !  Internal reference source
            scalar/float            A_HI_DIHEDRAL
                                    !  Dihedral
            array/float/dim=4       A_HI_BOL_ASSEM
                                    !  Bolometer assembly
            scalar/float            A_HI_MIRROR
                                    !  Mirror assembly
            array/float/dim=4       A_HI_CAL_RESISTORS
                                    !  Cal resistors
            scalar/float            A_HI_XCAL_CONE
                                    !  Additional xcal temp
            scalar/float            A_HI_COLLIMATOR
                                    !  Collimator
            !  B side low current GRTS
            scalar/float            B_LO_XCAL_TIP
                                    !  External calibrator tip
            scalar/float            B_LO_SKYHORN
                                    !  Sky horn
            scalar/float            B_LO_REFHORN
                                    !  Reference horn
            scalar/float            B_LO_ICAL
                                    !  Internal reference source
            scalar/float            B_LO_DIHEDRAL
                                    !  Dihedral
            array/float/dim=4       B_LO_BOL_ASSEM
                                    !  Bolometer assembly
            scalar/float            B_LO_MIRROR
                                    !  Mirror assembly
            array/float/dim=4       B_LO_CAL_RESISTORS
                                    !  Cal resistors
            scalar/float            B_LO_XCAL_CONE
                                    !  Additional xcal temp
            scalar/float            B_LO_COLLIMATOR
                                    !  Collimator
            !  B side high current GRTS
            scalar/float            B_HI_XCAL_TIP
                                    !  External calibrator tip
            scalar/float            B_HI_SKYHORN
                                    !  Sky horn
            scalar/float            B_HI_REFHORN
                                    !  Reference horn
            scalar/float            B_HI_ICAL
                                    !  Internal reference source
            scalar/float            B_HI_DIHEDRAL
                                    !  Dihedral
            array/float/dim=4       B_HI_BOL_ASSEM
                                    !  Bolometer assembly
            scalar/float            B_HI_MIRROR
                                    !  Mirror assembly
            array/float/dim=4       B_HI_CAL_RESISTORS
                                    !  Cal resistors
            scalar/float            B_HI_XCAL_CONE
                                    !  Additional xcal temp
            scalar/float            B_HI_COLLIMATOR
                                    !  Collimator
          endmap

          map
            array/float/dim=64      GRT
          endmap

        endunion

        union

          map

            array/float/dim=8       TEMP_CTRL
                                    !  Temperature controllers
            array/float/dim=2       IPDU_TEMP
                                    !  IPDU temps A,B
            array/float/dim=4       CNA_TEMP
                                    !  Channel temps
            array/float/dim=2       DBX_TEMP
                                    !  Drive box temps
            array/float/dim=2       STAT_MON_TEMP
                                    !  Status monitor temp
            scalar/float            PAMP_CHAN
                                    !  Channel preamp
            scalar/float            PAMP_OP
                                    !  Optical preamp
            array/float/dim=2       HOT_SPOT
                                    !  Hot spot heater A,B
            array/float/dim=2       MTM_CAL_MTR
                                    !  MTM/Cal motors
            array/float/dim=2       MTM_POS
                                    !  MTM position
            array/float/dim=4       BOL_VOLT
                                    !  Bolometer voltages
            array/float/dim=20      IPDU_VOLT
                                    !  IPDU voltages
            array/float/dim=12      IPDU_AMP
                                    !  IPDU currents
          endmap

          map
            array/float/dim=62     GROUP1
          endmap

        endunion
  endstructure

  structure en_xcal
!
!        Science Mode Setup
!
        array/word/dim=2        POS
                                ! XCal position
                                !   0 = error
                                !   1 = in sky horn
                                !   2 = stowed (out of horn)
                                !   3 = transit (between in and out)
        array/byte/dim=50       XCAL_SPARES
  endstructure

  structure/dim=4 chan
!
! Channel specific setup fields.
!
        scalar/byte             UP_SCI_MODE
                                !  uP science mode
        scalar/byte             FAKEIT
                                !  Fake-it
        scalar/byte             UP_ADDS_PER_GROUP
                                !  uP adds per group
        scalar/byte             UP_SWPS_PER_IFG
                                !  uP sweeps per ifg
        scalar/byte             XMIT_MTM_SPEED
                                !  MTM speed at transmit
        scalar/byte             XMIT_MTM_LEN
                                !  MTM length at transmit
        scalar/word             SCI_GAIN
                                !  Science gain
        scalar/byte             DITHER
                                !  Dither bit
        array/byte/dim=15       SETUP_SPARES
                                !  Setup spares
  endstructure

  structure/dim=2 en_tempdiff
!
! Temperature difference between bracketing major frames
! in units of a tenth of a millikelvin.
!
        scalar/word             XCAL
                                ! External calibrator temp diff
        scalar/word             ICAL
                                ! Internal ref source temp diff
        scalar/word             SKYHORN
                                ! Sky horn temp diff
        scalar/word             REFHORN
                                ! Reference horn temp diff
        scalar/word             DIHEDRAL
                                ! Dihedral temp diff
        scalar/word             COLLIMATOR_MIRROR
                                ! Collimator and mirror temp diff
        array/word/dim=4        BOL_ASSEM
                                ! Bolometer assembly temp diff
  endstructure

  structure en_tail
!
! Engineering record trailer.
!
        array/byte/dim=8        ENGTAIL_SPARES
                                !  Channel specific spares
        scalar/byte             HSKP_FLAG
                                !  Housekeeping flag
                                !  0=housekeeping present
                                !  1=no housekeeping data for
                                !  time of engineering record
        scalar/float            LMAC_ANALOG_TEMP
                                !  LMAC temperature for analog
                                !  converter. 
                                !  Spacecraft Sides 1 and 2
                                !  read FIRAS A Side only.
        scalar/float            LMAC_DIGITAL_TEMP
                                !  LMAC temperature for digital
                                !  converter. 
                                !  Spacecraft Sides 1 and 2
                                !  read FIRAS A Side only.
        array/byte/dim=2        TLM_QUAL_MAJ_FRM
                                !  Overall telemetry quality
                                !  for MJF
!
! Fill the record out to a block boundary.
!
        array/byte/dim=9        ENG_SPARES
                                !  Engineering record spares
  endstructure

end_record

--------------------------------------------------------------------------------

Some additional notes relevant to various fields in the engineering record RDL
are as follows.

For the EN_HEAD structure:
    GMT and TIME - The Julian time in character and binary format of the
engineering record; this is the average time of the science records with which
this engineering record is associated.
    BIN_TIME - The binary Julian time of the science records (from one to four)
with which an engineering record is associated.  The four values are for the
right high, right low, left high, and left low channels respectively.  A zero
time value in any of the four positions indicates that no science record in
that channel is associated with this engineering record.
    DQ_SUMMARY_FLAG and ATT_SUMMARY_FLAG] - The data quality and attitude
quality as stored in the associated science records.

For the EN_STAT structure:
    GROUP1 - The sixteen microprocessor status words; these data may be
referenced either by their individual names or as mapped into the GROUP1 field.

for the EN_ANALOG structure:
    GRT - The 64 GRT temperature readings.  The data are stored in three maps,
the first divided into four groups according to instrument side and high or low
current, the second with descriptions of the GRT positions, and the third by
number.
    GROUP1 - The other temperature readings, bolometer voltages, and Internal
Power Distribution Unit voltages and currents.

For the EN_XCAL, CHAN, and EN_TEMPDIFF structures:
    POS - The external calibrator position field indicates whether the data are 
sky or calibration data. A value of 1 indicates that the XCAL is in the horn
and the interferograms are thus calibration data.  A value of 2 indicates that
the XCAL is completely out of the horn and the interferograms are sky data.
Data with any other value are not used.
    CHAN - This structure stores some of the information associated with the
science records corresponding to this engineering record.
    EN_TEMPDIFF - Stores temperature differences between the bracketing
housekeeping major frames from which this engineering record was derived. 
These values are used for consistency checking in the FIRAS pipeline software
to eliminate data whose housekeeping values vary too much between major frames.

--------------------------------------------------------------------------------

!
! FIRAS Housekeeping Data Record.
!
RECORD NFS_HKP NFS_HKP

  STRUCTURE CT_HEAD
!
! COBETRIEVE header for time-ordered files.
!
        scalar/text/length=14   GMT
                                !  GMT of start collect
        scalar/adt              TIME
                                !  Binary time
        array/byte/dim=6        SPACE_TIME
                                !  Spacecraft time
        scalar/long             MJR_FRM_NO
                                !  Major frame number
        scalar/long             ORBIT
                                !  Orbit number
!
! The original 28 COBETRIEVE spares are now reserved
! for the COBE subsystems. The first 20 bytes are
! reserved for use by the INGEST Subsystem.
!
        scalar/byte             HSKP1_TLM_FMT
                                !  Telemetry format for
                                !    major frame 1
        scalar/byte             HSKP2_TLM_FMT
                                !  Telemetry format for
                                !    major frame 2
        array/byte/dim=18       INGEST_SPARES
                                !  Spares
!
! The remaining 8 bytes are reserved for use by the
! instrument subsystems.
!
        scalar/word             DATASET_ID
                                !  CT dataset ID
        array/byte/dim=6        INSTR_SPARES
                                !  Spares
  ENDSTRUCTURE

  STRUCTURE/DIM=2 FRAME
!
! The main contents of the housekeeping record.
!
        structure HSKP_HEAD
!
! Housekeeping header.
!
        array/word/dim=8        STAT_MONITOR_CMD
                                !  Status monitor command
        array/byte/dim=8        IPDU_STAT
                                !  IPDU status
        array/byte/dim=2        DWELL_STAT
                                !  Dwell status
        array/byte/dim=2        LVDT_STAT
                                !  MTM status
        array/byte/dim=4        U_PROC_STAT
                                !  Micro processor status
        array/byte/dim=4        BOL_CMD_BIAS
                                !  Bolometer command bias
        endstructure

        structure TEMPS
!
! Instrument temperatures.
!
        structure/dim=4 SIDE_AMP
        union

          map
            scalar/word         EX_CAL
                                !  External calibrator
            scalar/word         SKY_HORN
                                !  Sky horn
            scalar/word         REF_HORN
                                !  Reference horn
            scalar/word         IREF_SOURCE
                                !  Internal reference source
            scalar/word         DIHEDRAL
                                !  Dihedral
            array/word/dim=4    BOL_ASSEM
                                !  Bolometer assembly
            scalar/word         MIRROR
                                !  Mirror assembly
            array/word/dim=4    CAL_RESIST
                                !  Cal resistors
            scalar/word         EX_CAL_SEGMENT
                                !  Additional external
                                !    calibrator temps
            scalar/word         COLIMATOR
                                !  Colimator
          endmap

          map
            array/word/dim=16   GRT
          endmap

        endunion
        endstructure

        array/byte/dim=2        IPDU
                                !  IPDU temperatures A,B
        scalar/byte             DRIVE_BOX_A
                                !  Drive box temp A
        scalar/byte             CHAN_PRE_AMP
                                !  Channel preamp
        array/byte/dim=4        CHAN_TEMP
                                !  Channel temps
        array/byte/dim=2        STAT_MON
                                !  Status monitor temp
        array/byte/dim=2        HOT_SPOT_CURRENT
                                !  Hot spot heater A,B
        scalar/byte             OPTICAL_PREAMP
                                !  Optical preamp
        scalar/byte             DRIVE_BOX_B
                                !  Drive box temp B
        endstructure

        structure V_AND_I
!
! IDPU voltages and currents.
!
       union

         map
           array/byte/dim=2     DIG_CONV_N_15
                                !  Digital conv, -15v,
                                !    sides A and B
           array/byte/dim=2     DIG_CONV_P_15
                                !  Digital conv, +15v, 
                                !    sides A and B
           array/byte/dim=2     DIG_CONV_P_5
                                !  Digital conv, +5v, 
                                !    sides A and B
           array/byte/dim=2     ANA_CONV_P_15
                                !  Analog conv, +15v, 
                                !    sides A and B
           array/byte/dim=2     ANA_CONV_N_15
                                !  Analog conv, -15v, 
                                !    sides A and B
           array/byte/dim=2     BIAS_PRE_REG
                                !  Bias pre-reg, +25v,
                                !    sides A and B
           array/byte/dim=2     INT_PS_P_28
                                !  Int. P.S., +28v, 
                                !    sides A and B
           array/byte/dim=2     INT_PS_P_15
                                !  Int. P.S., +15v, 
                                !    sides A and B
           array/byte/dim=2     INT_PS_N_15
                                !  Int. P.S., -15v, 
                                !    sides A and B
           array/byte/dim=2     INT_PS_P_5
                                !  Int. P.S., +5v, 
                                !    sides A and B
         endmap

         map
           array/byte/dim=20    IPDU_VOLT
         endmap

       endunion

       union

         map

           array/byte/dim=2     CUR_BIAS_PRE_REG
                                !  Bias pre-reg cur, 
                                !    sides A and B
           array/byte/dim=2     CUR_ANA_CONV
                                !  Analog conv cur, 
                                !    sides A and B
           array/byte/dim=2     CUR_DIG_CONV
                                !  Digital conv cur,
                                !    sides A and B
           array/byte/dim=4     CON_CURRENT
                                !  Const cur, RH,LH,RL,LL
           array/byte/dim=2     CON_INT_CONV
                                !  Int conv cur, 
                                !    sides A and B
         endmap

         map
           array/byte/dim=12    IPDU_AMP
         endmap

       endunion

       array/byte/dim=2         MTM_CAL_MOTOR
                                !  MTM cal motor, 
                                !    sides A and B
       array/byte/dim=4         BOL_BIAS_VOLT
                                !  Bolometer bias,
                                !    RH,RL,LH,LL
        endstructure
  ENDSTRUCTURE

  STRUCTURE HSKP_TAIL
!
! Additional housekeeping information.
!
        scalar/text/length=14   GMT_MJF2
                                !  Major frame 2 time tag
        scalar/word             SPARES
  ENDSTRUCTURE

  STRUCTURE/DIM=2 MJ_FRM
!
! Notch filters and spares
!
        array/byte/dim=5        NTCH_FLT_A
                                !  A side notch filters
        array/byte/dim=5        NTCH_FLT_B
                                !  B side notch filters
        scalar/byte             TLM_QUAL_MAJ_FRM
                                !  Overall telemetry quality  
                                !  for major frame  
        scalar/byte             POWER_A_STATUS
                                !  Status bits in Subcom Word
                                !  105 for power to A side	
                                !  Bits 7:6 MTM & XCAL motor
                                !    power
                                !  Bits 5:4 IPDU Bias prereg.
                                !    converter.
                                !  Bits 3:2 IPDU Internal conv.
                                !  Bits 1:0 IPDU Analog & dig.
                                !    converter.
        scalar/byte             POWER_B_STATUS
                                !  Status bits in Subcom Word
                                !  105 for power to B side; bit
                                !  order same as for A side
        scalar/byte             LMAC_ANALOG_TEMP
                                !  LMAC temperature for analog
                                !  converter. 
                                !  Spacecraft Sides 1 and 2
                                !  read FIRAS A Side only.
        scalar/byte             LMAC_DIGITAL_TEMP
                                !  LMAC temperature for digital
                                !  converter.
                                !  Spacecraft Sides 1 and 2
                                !  read FIRAS A Side only.
        array/byte/dim=17       SPARES
                                !  Spare bytes
  ENDSTRUCTURE

END_RECORD

--------------------------------------------------------------------------------

!
! FIRAS Ancillary Housekeeping Data Record.
!
record NFS_ANC NFS_ANC

  structure ct_head
!
! COBETRIEVE header for time-ordered files.
!
        scalar/text/length=14   GMT
                                !  GMT of start collect
        scalar/adt              TIME
                                !  Binary time
        array/byte/dim=6        SPACE_TIME
                                !  Spacecraft time
        scalar/long             MJR_FRM_NO
                                !  Major frame number
        scalar/long             ORBIT
                                !  Orbit number
!
! The original 28 COBETRIEVE spares are now reserved
! for the COBE subsystems. The first 20 bytes are
! reserved for use by the INGEST Subsystem.
!
        scalar/byte             HSKP1_TLM_FMT
                                !  Telemetry format for
                                !    major frame 1
        scalar/byte             HSKP2_TLM_FMT
                                !  Telemetry format for
                                !    major frame 2
        array/byte/dim=18       INGEST_SPARES
                                !  Spares
!
! The remaining 8 bytes are reserved for use by the
! instrument subsystems.
!
        scalar/word             DATASET_ID
                                !  CT dataset ID
        array/byte/dim=6        INSTR_SPARES
                                !  Spares
  endstructure

!
! The main contents of the ancillary housekeeping record.
!
  structure/dim=2 frame
    array/byte/dim=128      MINOR_FRAME_STATUS_BITS
                            !  MTM scan direction bit,
                            !  XCAL status bit:
                            !   in or out=1, neither=0,
                            !  MTM scan length,
                            !  MTM scan speed,
                            !  Four uP data ready bits
    array/byte/dim=32       SPARES
  endstructure

  scalar/adt                GMT_MJF2
                            !  Major frame 2 time tag

end_record

--------------------------------------------------------------------------------

!
! FIRAS Engineering Mode Timing Data Record
!
RECORD NFS_EMF NFS_EMF

  Structure CT_HEAD
!
! COBETRIEVE header for time-ordered files.
!
        scalar/text/length=14   GMT
                                !  GMT of start collect
        scalar/adt              TIME
                                !  Binary time
        array/byte/dim=6        SPACE_TIME
                                !  Spacecraft time
        scalar/long             MJR_FRM_NO
                                !  Major frame number
        scalar/long             ORBIT
                                !  Orbit number
!
! The original 28 COBETRIEVE spares are now reserved
! for the COBE subsystems. The first 20 bytes are
! reserved for use by the INGEST Subsystem.
!
        scalar/byte             HSKP1_TLM_FMT
                                !  Telemetry format for
                                !    major frame 1
        scalar/byte             HSKP2_TLM_FMT
                                !  Telemetry format for
                                !    major frame 2
        array/byte/dim=18       INGEST_SPARES
                                !  Spares
!
! The remaining 8 bytes are reserved for use by the
! instrument subsystems.
!
        scalar/word             DATASET_ID
                                !  CT dataset ID
        array/byte/dim=6        INSTR_SPARES
                                !  Spares
  EndStructure

  Structure SCI_HEAD
!
! Science data channel header written by the FIRAS stripper
!   and FIRAS Preprocessor.
!
        scalar/word             CHAN_ID
                                !  Channel id
        scalar/word             GAIN
                                !  Gain
        scalar/word             MTM_SPEED
                                !  MTM speed
        scalar/word             MTM_LENGTH
                                !  MTM scan length
        array/byte/dim=60       DATA_QUAL
                                !  Data quality flags
        array/word/dim=8        DATA_READY
                                !  Data ready flags
!
! Scan data.
!
        scalar/word             SC_HEAD0
                                !  Data block synchronization
        scalar/byte             SC_HEAD1A
                                !  Block type (sci mode)
        scalar/byte             SC_HEAD1B
                                !  Block ID
        scalar/word             SC_HEAD2
                                !  SW version number
        scalar/word             SC_HEAD3
                                !  Status bits
        scalar/word             SC_HEAD4
                                !  Transmit time LSW
        scalar/word             SC_HEAD5
                                !  Transmit time MSW
        scalar/word             SC_HEAD6
                                !  Data check
        scalar/word             SC_HEAD7
                                !  No a/d samples for collect
                                !    cycle
        scalar/word             SC_HEAD8
                                !  Points process for collect
                                !    cycle
        scalar/word             SC_HEAD9
                                !  Number of added points 1,2,
                                !   3,8,or 12 "adds per group"
        scalar/word             SC_HEAD10
                                !  Data points per mirror sweep
        scalar/word             SC_HEAD11
                                !  Number of mirror sweeps
        scalar/word             SC_HEAD12
                                !  LSW frame counter
        scalar/word             SC_HEAD13
                                !  MSW frame counter
        scalar/word             SC_HEAD14
                                !  Deglitcher threshold factor
        scalar/word             SC_HEAD15
                                !  Noise level
        scalar/word             SC_HEAD16
                                !  S/L counter constants
        scalar/word             SC_HEAD17
                                !  Deglitcher Seed Sample
        scalar/word             SC_HEAD18
                                !  Command Counter
        scalar/word             SC_HEAD19
                                !  Program Checksum
        scalar/word             SC_HEAD20
                                !  Saturated Sample Count
        scalar/word             SC_HEAD21
                                !  Glitch total
        scalar/word             SC_HEAD22
                                !  Deglitcher overflow address
        scalar/word             SC_HEAD23
                                !  Division of IFG performed
                                !    (FCI RMS files only)
        scalar/word             SC_HEAD24
                                !  FCI raw science intermediate
                                !    dump data type
        scalar/word             SC_HEAD25
                                !  High/low channel indicator
                                !    'HI' = high
                                !    'LO' = low
  EndStructure

  array/word/dim=512            SC_ENG_DATA
                                !  MTM scan timing data

  array/byte/dim=312            EMF_SPARES
                                !  Spares

End_Record

--------------------------------------------------------------------------------

!
! FIRAS Digital Transient Response Function Record Structure
! 
record FEX_DTRF FEX_DTRF

       array/float/dim=128         TRANS
                                   ! Transient Response Functions
                                   !
                                   !    Stored in 8 records:
                                   !     RH or LH channel    1 - 4
                                   !        SS scan mode         1
                                   !        SF scan mode         2
                                   !        LS scan mode         3
                                   !        LF scan mode         4
                                   !     RL or LL channel    5 - 8
                                   !        SS scan mode         5
                                   !        SF scan mode         6
                                   !        LS scan mode         7
                                   !        LF scan mode         8
end_record

--------------------------------------------------------------------------------

!
!  FIRAS Glitch Profile Record Structure
!
Record FEX_GLTCHPRO FEX_GLTCHPRO

  Array/Float/Dim=512           GLTCHPRO
                                ! Glitch Profiles
                                !
                                !   First 510 points store actual profile;
                                !   point 511 is index of glitch peak
                                !   position; point 512 is offset from 511
                                !   to "true" peak position obtained by
                                !   parabolic interpolation.
                                !
                                !   Stored in 312 records; each group of 26
                                !   records has 1 record for adds-per-group=1,
                                !   2 for adds-per-group=2, and so on for
                                !   adds-per-group values 1,2,3,8, and 12.
                                !
                                !   Slow MTM Speed   1 - 104
                                !      RH            1 -  26
                                !      RL           27 -  52
                                !      LH           53 -  78
                                !      LL           79 - 104
                                !   Fast MTM Speed 105 - 208
                                !      RH          105 - 130
                                !      RL          131 - 156
                                !      LH          157 - 182
                                !      LL          183 - 208
                                !   Fake-it Mode   209 - 312
                                !      RH          209 - 234
                                !      RL          235 - 260
                                !      LH          261 - 286
                                !      LL          287 - 312
End_Record

--------------------------------------------------------------------------------

!
! Legendre Polynomial Basis Vectors for Baseline Subtraction
!
record FEX_BASIS FEX_BASIS

array/double/dim=(512,5)  LEG_POLY
                          ! Legendre polynomials for 512 index points.
                          ! Second index value is degree of polynomial
                          ! plus one.  Independent variable is divided
                          ! by 512 to decrease dynamic range for better
                          ! precision in the fit.
end_record