DATA DICTIONARY: HIRS 1B* DATA RECORD

ANALOG_DATA Sixteen selected Digital "A" temperature sensor and

voltage outputs from the 16 and 32 second subcoms and fourteen

Digital "B" one_bit status telemetry points from the 3.2 second

subcom. Descriptions of the Digital "A" points and the

Digital "B" points can be found in Figures 18.2-9 and 18.2-10 of

the HIRS/3 Analog Telemetry in chapter 18 of the NOAA-K P & C

Handbook, respectively.

Type: I*1

ANALOG_GROUND_1 HIRS element 62, bits 261-273.

ANALOG_GROUND_2 HIRS element 62, bits 274-286.

ANALOG_INVALID_BIT_FLAGS Sixteen bit flags associated with the

sixteen HIRS Digital-B analog items. If the associated invalid

bit flag is set for an analog telemetry item, It means that the

telemetry word was not updated during the most recent cycle,

probably due to a dropped minor frame. The telemetry word thus

retains its last update value, and the invalid bit for that word

is set to let users know that the telemetry word is suspect.

type: I*4 (bits 1- 16)

APITCH The value provided in the TIP's CPU parameter APITCH.

It represents the Euler error angle. See the Programming and

Control Handbook (Reduction of CPU Telemetry) for instructions

for the conversion of this integer value to an angular measure.

AROLL The value provided in the TIP's CPU parameter AROLL. It

represents the Euler error angle. See the Programming and Control

Handbook (Reduction of CPU Telemetry)for instructions for the

conversion of this integer value to an angular measure.

ATTITUDE_CONTROL Indicates whether the earth location

fields in this record where corrected for deviations in

spacecraft attitude. A value of 1 indicates the correction has

been made; a value of 0 indicates it has not. Currently this

field will always be set to 0.

******currently working on this definition*************

See NAVIGATION_STATUS_BIT_FIELD for 1b file format.

AYAW The value provided in the TIP's CPU parameter AYAW. It

represents the Euler error angle. See the Programming and Control

Handbook (Reduction of CPU Telemetry) for instructions for the

conversion of this integer value to an angular measure.

BASEPLATE_TEMP Analog telemetry point. {note 2}

Measures the output of the thermistor located on the baseplate.

CALIBRATION_CHAN_QUALITY_FLAGS A 2-dimensional array of Boolean

codes -- one column for each of the IR channels -- indicating

the occurrence (1--> yes, 0 --> no) of the channel specific

conditions that follow:

(1) all bad black body counts for this

scan line.

(2) all bad space view counts for

this scan line.

(3) all bad PRTs for this scan line.

(4) marginal blackbody view counts for

this line.

(5) marginal space view counts for this

line.

(6) marginal PRT temperatures on this line.

CALIBRATION_PROBLEM_CODE An array of Boolean codes

indicating the occurrence ( 1--> yes, 0 --> no) of the conditions

given below. These indicators apply to the scan line as a

whole. Indicators for specific channel conditions are given by

the CALIBRATION_CHAN_QUALITY_FLAGS.

(1) scan line was not calibrated

because of bad time.

(2) scan line was calibrated

using fewer than the preferred

number of scan lines because of

proximity to start or end of

data set or to a data gap.

(3) scan line was not calibrated

because of bad or insufficient

PRT data.

(4) scan was calibrated but with

marginal PRT data channel

indicators.

(5) some uncalibrated channels

for this scan line (see channel

indicators).

(6) uncalibrated due to

instrument mode.

CLOCK_DRIFT_CORRECTION Indicates whether the scan time given in

this record has been corrected for the drift in the spacecraft

clock. A value of 0 indicates no correction has been made, and

a value of 1, that the time in TIME_OF_DAY_OF_SCAN has been

corrected for drift.

CLOCK_DRIFT_DELTA The difference between the time reported on

the data record and that reported by the spacecraft. The time

reported on the data record has been corrected for the drift of

the spacecraft's clock. If the CLOCK_DRIFT_DELTA is added to

TIME_OF_DAY_OF_SCAN, the time reported by the spacecraft will

result.

COLD_TARGET_PRT The PRT readings in counts of the cold

calibration target. Note that these are included merely for

completeness; these readings are not used in the calibration.

HIRS element 59, bits 27-286. {note 1} {note 4}

COOLER_HOUSING_TEMP One reading of the patch temperature. HIRS

element 62, bits 131-143. {note 1} {note 4}

DATA_FILL Indicates whether any of the constituent minor frames

of the current HIRS scan were missing (1 --> yes ). (See

HIRS_ELEMENT_QUALITY below.) See Quality_Indicator_Bit_Field for

1b format.

DATA_VERIFICATION_BINARY_CODE Verification codes as sent from the

spacecraft in HIRS element 63.

DAY_OF_YEAR_OF_SCAN The day of the year on which the scan

began, set by the PDP based upon the date and time information

provided in the data stream.

DIG_B_DATA One_bit staus telemetry generated by the TIP every

3.2 seconds. In the HIRS/3 instrument, the Digital "B" outputs are

discrete bilevel signals of 0 or 5V nominal relating to a Logic 1

or zero.

DIG_B_INVALID_BIT_FLAGS Fourteen bit flags associated with the

fourteen HIRS Digital-B telemetry items. If the associated

invalid bit flag is set for an analog telemetry item, It means

that the telemetry word was not updated during the most recent

cycle, probably due to a dropped minor frame. The telemetry

word thus retains its last update value, and the invalid bit

for that word is set to let users know that the telemetry word

is suspect.

type: I*4 (bits 2- 15)

DO_NOT_USE_SCAN Is a general quality indicator set by the PDP.

If its value is 1, the scan line should be treated by the

product processors as though it were missing. This flag will be

set if the calibration cannot be performed, or if the earth

location information is missing or erroneous, or if the scan

contains a corrupt time code and a valid time can not be

inferred. <<1b: bytes 29-32, bit 31>> {note 8}

DWELL Indicates whether the HIRS instrument has been commanded

into Dwell Mode (1 --> yes). Set by the PDP. << TBC: We

determine whether the instrument is in the Commnaded Position

Mode by looking at bits 50-52, & 58 of HIRS element 63 (see

UIIS). If any of these bits is 0, the instrument has been

commanded to the corresponding position. This condition should

disable calibration and earth location. The DO_NOT_USE_SCAN flag

should be set.>> See Quality_Indicator_Bit_Field for 1b format.

EARTH_LOC_ATTITUDE_CORRECTED A value of one indicates that earth

location was corrected for TIP Euler angles. See Navigation

Status Bit Field. See NAVIGATION_STATUS_BIT_FIELD for 1b file

format.

EARTH_LOC_INDICATOR Normally zero, this indicator indicates

the occurrence of a problem in earth location. See Navigation

Status Bit Field. See NAVIGATION_STATUS_BIT_FIELD for 1b file

format.

0 = earth location available

1 = user ephemeris file greater than 24 hours old

2 = no earth location available

EARTH_LOC_PROBLEM_CODE Provides information about the status

of earth location if NO_EARTH_LOC_THIS_SCAN is set to "TRUE".

(1) not earth-located because of bad

time.

(2) questionable earth location

because of questionable time

code.

(3) questionable earth location

because of marginal agreement with

reasonableness check.

(4) earth location probably bad --

fails reasonableness check.

ELECTRONICS_POWER Indicates if electronic power is being supplied

to all electronic and data handling systems not provided by the

"Instrument On" command.

ELECTRONICS_TEMP Measures the output of the thermistor located

inside the electronics box. {note 6}

ELEC_CAL_DIG2ANALOG_CONV_VOLTS << was _TEMP>> Five readings of

a voltage associated with the electronic calibration digital

to analog converter. HIRS element 61, bits 222-286. {note 1}

{note 4}

FILTER_MOTOR_CURRENT Supplies electrical power to the filter wheel

motor

FILTER_WHEEL_HOUSING_HEATER_CURR Five readings of the filter

wheel housing's heater current. HIRS element 61, bits 27-91.

{note 1} {note 4}

FILTER_WHEEL_HOUSING_TEMP The PRT counts for the filter wheel

housing. There are five samples from each of 4 PRTs. HIRS

element 60, bits 27-286. {note 1} {note 4}

FILTER_WHEEL_MOTOR_TEMP Measures the output from the temperature

sensor located on the filter wheel motor.

FIRST_AFTER_DATA_GAP The current scan line immediately succeeds

a gap of one or more scan lines. The scan line number will take

into account the missing scans. Set by the PDP based upon

major/minor frame accounting and the availability of information

from the spacecraft.<<1b: bytes 29-32, bit 29>> {note 8}

FIRST_GOOD_TIME_AFTER_UPDATE The spacecraft clock has been

updated. This scan is the first subsequent scan whose time is

judged good. Set by the PDP. <<1b: bytes 29-32, bit 26>>

{note 8}

FIRST_STAGE_RADIATOR_TEMP Five readings of the first stage

radiator PRT in counts. HIRS element 61, bits 27-91. {note 1}

FIRST_STATUS_WORD The first of two status words {note 5} from

the digital A data, this field contains bits 40-52 {note 1} of

element 63 left justified; i.e., the 13 most significant bits

contain the status word; the 3 remaining bits are all zero.

FRAME_TIME_ERROR Sixty-four item array of indicators associated

with the sixty-four minor frames in a scan line. A value of one

indicates this frame is suspect due to a time error.

See Quality_Indicator_Bit_Field for 1b format.

GDTIME Geometric Data Time taken from the TIP CPU telemetry.

INSTRUMENT_STATUS_CHANGE One byte indicator, if set to one

indicates instrument status changed with this scan. {note 8}

INSUFFICIENT_DATA_FOR_CALIBRATION One byte indicator, if set

to one indicates this scan line was not calibrated. {note 8}

See CALIBRATION_PROBLEM_CODE for possible reasons scan line was

not calibrated.

LAT_LON_DEGREES The geodetic latitude and longitude, in that

order, of each of the fields of view along the scan line. The

latitude's range is +/- 90 degrees, with 0 at the equator and

positive angles to the north. The longitude is measured from

Greenwich, with positive values to the east; its range is +/-

180 degrees.

LINE_COUNTER The line counter taken from HIRS element 63.

Normally this will cycle from 0 to 39 indicating the position

within the superswath, i.e., the number of scan since the last

calibration. For HIRS/3 line 0 is the space view, line 1 is the

view of the internal warm target (IWT), and lines 3 through 39

are scans of the earth. The HIRS calibration cycle can be

commanded off, in which case the instrument continuely scans the

earth and does not look either at the black body or space. In

this case LINE_COUNTER will cycle 0, 1, ..., 8191, 0,..., and

the field CAL_DISABLE will contain 1.

LOCAL_AZIMUTH_ANGLE The angle between the projections onto

the tangent plane of lines drawn from the viewed point to the

sun and from the viewed point to the satellite. It is measured

from sun to satellite and has a range of +/- 180 degrees; angles

eastward from the sun are positive.

LOCAL_ZENITH_ANGLE The angle from a line drawn from the viewed

point to the satellite and one from the viewed point normal to its

tangent plane. The range of satellite zenith angle is 0 to 90

degrees.

MAJOR_FRAME_COUNTER The TIP major frame counter of the major

frame from which this scan line was extracted. Set by the PDP

directly from the raw data.

MINOR_FRAME_BIT_FLAGS -- The minor frame quality

bit flags as provided by the ingester. Each of the 64 elements

corresponds to one of the constituent TIP minor frames used to

construct the HIRS scan. (See the AIP 1a requirements document

for the meaning of each of the bits.)

MINOR_FRAME_HEADER_ELEMENTS A sixty-four word array that contains

header elements for minor frames 0 - 63.

(1) bits 31-24: scan encoder position

(2) bits 23-19: electronic cal level indicator

(3) bits 18_13: <zero fill>

(4) bits 12-7: channel 1 period monitor

(5) bits 6-1: element number

(6) bit 0: filter sync disignator

MIRROR_LOCKED The mirror was locked during this frame. Normal

earth scanning was disrupted. See Quality_Indicator_Bit_Field for

1b format.

MIRROR_POSITION_ERROR There was a mirror reposition error during

this frame. See Quality_Indicator_Bit_Field for 1b format.

MIRROR_REPOSITION The mirror was moving during this frame.

See Quality_Indicator_Bit_Field for 1b format.

NAVIGATION_STATUS_BIT_FIELD This field contains the following

navigation status information:

(1) bits 31-17: <zero fill>

(2) bit 16: 1 = earth location corrected for TIP

Euler Angles.

(3) bits 15-12: earth location indicator (0 =

earth location available; 1 = user ephemeris

files greater than 24 hours old; 2 = no earth

location available).

(4) bits 11-8: spacecraft attitude control (0 =

operating in YGC or NOMINAL mode; 1 = operating

in another mode; 2 = attitude exceeds nominal

tolerance; 3= both 1 and 2).

(5) bits 7-4: attitude SMODE (0 = NOMINAL mode; 1 =

rate nulling mode; 2 = YGC mode; 3 = search

mode; 4 = coast mode).

(6) bits 3-0: attitude PWTIP$AC

(0 = NOMINAL mode/no test; 1 = yaw axis test in

progress; 2 = roll axis test in progress;

3 = pitch axis test in progress)

in progress).

NEG_CAL The counts resulting from the negative electronic

calibration as reported by the spacecraft. HIRS element 56,

bits 27-286. {note 1}

NO_EARTH_LOC_THIS_SCAN The location of the FOVs of this scan

line are unavailable. See EARTH_LOC_PROBLEM_CODE for reason.

Set by the PDP. <<1b: bytes 29-32, bit 27>> {note 8}

OBSERVATIONS The radiometric counts from the instrument during

the current scan of space, the warm target, or the earth.

ORBIT_NODE This field indicates the direction of the spacecraft

at the time of the scan. A value of zero indicates the

spacecraft is heading north (ascending), a value of one that it

is going south (descending).

PACS_ERROR PACS QC errors have been detected in at least one

of the minor frames that comprise this scan. Set by the PDP

based upon the Minor Frame Quality Indicators in the 1a stream,

this flag summarizes the quality indicators for all the TIP

minor frames that were used to generate this HIRS scan line.

In particular if the PACS reported any of the following in any

of the constituent minor frames, PACS_ERROR will be set to 1:

time error, data gap, bit sync status, frame sync word,

frame_sync lock, flywheeling, bit slip, AIP parity.

<<Was DACS_ERROR.>> See Quality_Indicator_Bit_Field for

1b format.

PATCH_CONTROL_POWER HIRS element 62, bits 144-156. {note 1}

PATCH_TEMP_EXPANDED Five readings of the patch PRT, in counts.

HIRS element 61, bits 27-91. {note 1}

PATCH_TEMP_FULL_RANGE HIRS element 62, bits 92 104

PITCH_ERROR_CORRECTION The value provided in the TIP's CPU

parameter APITCH. It represents the Euler error angle. See the

Programming and Control Handbook (Reduction of CPU Telemetry)

for instructions for the conversion of this integer value to an

angular measure.

POS_CAL The counts resulting from the positive electronic

calibration as reported by the spacecraft.

PRIMARY_CAL_COEFS The calibration coefficients computed by the

PDP for the HIRS IR channels using the primary calibration

algorithm. These are the calibration coeffieints that should be

used to convert radiometric counts from channels 1 - 19 in the

current scan line to radiance. (See OBSERVATIONS.)

COEFFICIENT:0 IS INTERCEPT

1 IS SLOPE

2 IS QUADRATIC

PRIMARY_TELESCOPE_TEMP HIRS element 62, bits 40 - 62.

PWTIP$AC The "passive wheel test in progress" indicator from

the TIP CPU telemetry. The two-byte hex code given in the

telemetry has been stored as a one-byte indicator that can be

interpreted as follows:

0 --> normal (no test)

1 --> yaw axis test inprogress

2 --> roll axis test in progress

3 --> pitch axis test in progress

-1 --> attitude monitoring locked out

(reference: KLM Telemetry List, Figure 27)

See NAVIGATION_STATUS_BIT_FIELD for 1b file format.

QUALITY_INDICATOR_BIT_FIELD Integer*4 word, for bits 7 through

1, if bit is on(=1) then the statement is true. Corresponding

one-byte indicators are also defined for these flags.

bit7: this frame suspect due to a time error.

bit6: this frame contains data gap data fill.

bit5: this frame contains TIP dwell data fill.

bit4: data suspect due to PACS QC error.

bit3: mirror locked during this frame.

bit2: mirror position error during this frame.

bit1: mirror was moving during this frame.

bit0: minor word odd parity bit.

ROLL_ERROR_CORRECTION The value provided in the TIP's CPU

parameter AROLL. It represents the Euler error angle. See the

Programming and Control Handbook (Reduction of CPU Telemetry)

for instructions for the conversion of this integer value to an

angular measure.

S/C_ALTITUDE The spacecraft altitude in kilometers. Computed

by AELDS, rounded by PDP to nearest km, and stored as an integer.

SCAN_LINE_NUMBER The relative scan number within the period of

the 1b data set, starting with 1. Scan_line_number will take

into account missing scans and thus attempt to give an accurate

count of the number of scan lines generated by the spacecraft.

Set by the PDP.

SCAN_MIRROR_TEMP Output of thermal sensor attached to the scan mirror.

SCAN_MOTOR_CURRENT Electrical power applied to the scan motor to

provide required stepping torque levels.

SCAN_MOTOR_TEMP Output of a thermistor attached to the scan motor and

connected to a passive conditioning circuit supplied by the +28Vdc

Telemetry Power.

SCAN_SEQUENCE_COUNTER The line number of the scan within a

major frame. This number will vary from 1 to 5.

<<1b: bytes 17 & 18>>

SCAN_TYPE A code indicating what the instrument is viewing.

0 --> earth

1 --> space

2 --> ICT (generally not applicable for HIRS/3)

3 --> IWT

Set by the PDP based on the same logic that sets

SCAN_SEQUENCE_COUNTER.

SECONDARY_CAL_COEFS Calibration resulting from the implementation of

the primary calibration algorithm and alternative CPIDS database

parameters.

SECONDARY_TELESCOPE_TEMP Output of sensor used to monitor the

temperature of secondary telescope.

SECOND_STATUS_WORD The second of two status words {note 5} from

the digital A data, this field contains bits 53-65 {note 1} of

element 63 left justified; i.e., the 13 most significant bits

contain the status word; the 3 remaining bits are all zero.

SMODE The attitude control submode word from the TIP CPU

telemetry. The two-byte hex code given in the telemetry has

been stored as a one-byte indicator that can be interpreted as

follows:

0 --> nominal

1 --> rate nulling

2 --> yaw gyrocompass

3 --> search

4 --> coast

(reference: KLM Telemetry List, Figure 27)

See NAVIGATION_STATUS_BIT_FIELD for 1b file format.

SOLAR_ZENITH_ANGLE The angle between a line drawn from the

viewed point to the sun and one from the viewed point normal to

its tangent plane. The range of solar zenith angle is 0 to

180 degrees. {note 4}

SECONDARY_CAL_COEFS The calibration coefficients computed by the

PDP for the IR channels using a secondary calibration

algorithm. These coeffieints are experimental and most users

should ignore them. Currently, identical to primary calibration.

TIME_OF_DAY_OF_SCAN The time of day in milliseconds of the start

of the scan. Set by the PDP based upon the date and time

information provided in the data stream. For HIRS, scan times

are inferred from the time of the TIP major frame. If the time

of the TIP major is not known and in the case of embedded AIP or

TIP, the time will be inferred from the AVHRR frame (GAC or

HRPT).

TIME_PROBLEM_CODE Provides an array of boolean codes

indicating the occurrence (or not) of the following conditions:

(1) time received from the s/c was

obviously bad. The time on this scan

can proably be inferred from those on nearby

scan lines.

(2) bad time received from s/c and can't

infer one reliably.

(3) pattern of scan times changed. May or may not be

related to clock update.

(4) start of a sequence that apparently repeats scan

times that have been previously accepted.

(5) spare.

TIME_SEQUENCE_ERROR One-byte indicator, if set to one then a time

sequence error was detected within this scan. See TIME_PROBLEM_CODE

for possible reasons. {note 8}

TIP_PARITY One_byte indicator, if set to one then minor word odd

parity bit is set. See Quality_Indicator_Bit_Field for 1b format.

VDC_NEGATIVE_15 -15-volt power supply provided by dc to dc converter