EDR Header

Fundamental Technologies

Voyager LECP Pages

Table C-10, Standard Experiment Data Record Header

Item

Word

Bits

Description

31-8

Project Identification - Identifies this tape as being written by the MJS77 project. The letters M, J, and S will be written in BCD.

7-4

Record Identification - Identifies which experiment and data subgroup to which this record pertains.

0000 =	Spare
0001 =	CRS Science Record
0010 =	IRIS (Unused in CR Modes)
0011 =	LECP Science Record
0100 =	MAG Science Record
0101 =	PLS Science Record
0110 =	PPS Science Record
0111 =	PRA Science Record
1000 =	PWS Science Record
1001 =	UVS Science Record
1010 =	RSS Science Record
1011 =	Engineering Record (DQSW = ZEROs)
1100 =	Unused
1101 =	Imaging Status Record Unused in CR6)
1110 =	Monitor Record (DQSW =ZEROs)
1111 =	Decommutation Map Record (DQSW =ZEROs)

3-0

Spacecraft Identification - Identifies the spacecraft transmitting this data.

0000 =	Flt 2
0001 =	Flt 1
0010 =	PTM
0011 =	Unknown
0100 =	SIM 1 (S/C 41)
0101 =	SIM 2 (S/C 42)
0110 =	Unused
:	:
1111 =	Unused

31-16

Physical Record Number - Sequential binary count of all physical records written on this EDR tape. The count is incremented by one after each successful write. This number is initially set to one (1).

15-8

Data Mode - Contains the telemetry format with respect to data content and data rate.

00₁₆ =	Engineering Zero - (See FID)
01₁₆ =	CR-2
02₁₆ =	CR-3
03₁₆ =	CR-4
04₁₆ =	CR-5
05₁₆ =	CR-6
06₁₆ =	CR-7
07₁₆ =	CR-1
08₁₆ =	Unused
09₁₆ =	IM-7
0A₁₆ =	GS-3
0B₁₆ =	IM-9
0C₁₆ =	PB-3
0D₁₆ =	PB-2
0E₁₆ =	PB-1
0F₁₆ =	GS-4
10₁₆ =	Unused
11₁₆ =	GS-2
12₁₆ =	IM-14
13₁₆ =	Unused
14₁₆ =	IM-12
15₁₆ =	IM-11
16₁₆ =	IM-10
17₁₆ =	0C-1
18₁₆ =	IM-8
19₁₆ =	Unused
1A₁₆ =	IM-6
1B₁₆ =	IM-5
1C₁₆ =	IM-6
1D₁₆ =	IM-3
1E₁₆ =	IM-2
1F₁₆ =	IM-13

7-6

Engineering Extraction Flag - Identifies whether the engineering data was extracted out of another data stream or was the primary data stream.

00 - stand-alone
11 = extracted

S/C Playback - Indicates that the data in this record is Spacecraft tape recorder playback data.

0 = no
1 = yes

This flag is set only for data extracted from PB-1, PB-2, and PB-3 telemetry mode data.

4-0

Spare
Starting Earth Received Time - Greenwich Mean Time (GMT) of the first PN bit of the first minor frame (MF) and contained in this record from which this record's prime data is extracted. Binary representation will be used.

31-16

Hour of Current Year - Binary hours since the beginning of the current year. See note following this table.

15-0

Seconds of Current Hour - Binary seconds since the beginning of current hour.

31-16

Milliseconds of Current Second - Binary milliseconds

15-8

Year - Binary year (i.e., 77, 78)

7-6

Data Source - Contains information as to whether the data was derived from an IDR or Multiple Wide Band data (which indicates that the data was logged at the station and then transmitted to JPL from the log tapes).

00₂ =	Unused
01₂ =	Real-Time
10₂ =	IDR
11₂ =	Replay

5-4

Golay Encoded Flag - Indicates that the data in this record have been Golay coded for transmission to Earth and decoded upon receipt at Earth, so any corrections will be flagged in the header of this record.

00₂ =	Not Golay Decoded
01₂ =	Golay Decoded
10₂ =	Unused
11₂ =	Unused

3-0

Segment Number - Other than those in the table below are zeros: (Only pertinent LECP entries are included here.)

Instrument/ Data Mode	Seg No.	Segs with MFs	MOD16 Count	MOD60 Count
LECP/CR1,2	1	CR1=1-80	A11	Even
	2	CR2=1-40	A11	Odd
LECP/CR6	1	1-75
	2	76-150
LECP/CR5	1	1-60	A11	0

31-16

Hour of Current Year - Binary hours since the beginning of the current year. See note at the end of this table.

15-0

Seconds of Current Hour - Binary seconds since the beginning of the current hour.

31-16

Millisecond of Current Second - Binary milliseconds.

15-8

Year - Binary year (i.e., 77, 78)

7-0

Software Version - contains identification (in binary) of the software system operating in the computer string which created the current record.

Spacecraft Event Time - Greenwich Mean Time (GMT) that corresponds to the Spacecraft Time of the first MF from which this records prime data was extracted, in binary representation. The format is as follows:

31-16

Hour of Current Year - Binary hours since the beginning of the current year. See note at the end of this table.

15-0

Seconds of Current Hour - Binary number of seconds since the beginning of the current hour.

31-16

Milliseconds of Current Second - Binary milliseconds

15-8

Year - Binary year (i.e., 77, 78)

7-4

Spacecraft Event Time Flag - 0=input by NORT file. 1=input by EDR PROC. Either all 0's or all 1's.

3-0

FDSC Correction Flag - Indicates that FDSC has been corrected in some manner. (Binary) There is bit for MOD 2, one for MOD 60, and one for line counts also. (1=corrected, 0=OK) 3=Space, 2=MOD 2, 1=MOD 60, 0=L.C.

31-16

MJS MOD 216 Count Word - Contains the 16-bit MM subcom time word for this record. Is incremented every 48 minutes.

15-8

MJS Mod 60 Count Word - Contains the module 60 spacecraft time as created within the FDS for the first minor frame received that is contained in this record. Increments every 48 seconds.

7-0

MJS Line Count Word - Contains the ISS line count which ranges between 1 and 800. Increments every 0.06 second.

31-24

23-16

Downlink Telemetry Rate - contains the rate at which the MJS spacecraft transmitted the telemetry data to earth (i.e., 40 to 115,200 bits/second). (Binary code)

00₁₆ =	Unused
01₁₆ =	10 BPS
02₁₆ =	20 BPS

23-16

03₁₆ = 40 BPS	0C₁₆ = 19,200 BPS
04₁₆ = 80 BPS	0D₁₆ = 21,600 BPS
05₁₆ = 160 BPS	0E₁₆ = 29,866 2/3 BPS
06₁₆ = 320 BPS	0F₁₆ = 44,800 BPS
07₁₆ = 640 BPS	10₁₆ = 67,200 BPS
08₁₆ =1200 BPS	11₁₆ = 67,200 BPS
09₁₆ = 1280 BPS	12₁₆ = 115,200 BPS
0A₁₆ = 2560 BPS	13₁₆ = 33,600 BPS
0B₁₆ = 7200 BPS	14₁₆ = 57,600 BPS
15₁₆ = 46 2/3 BPS	16₁₆ = 14,400 BPS

15-8

Effective Rate - Contains the effective bit rate of this data within the downlink telemetry rate. (Refer to downlink telemetry rate code.)

7-0

FID - Format ID word used only for Engineering record (extracted from telemetry data stream).

Bits	7	&	6	Format Type
	0		0	Engineering without AACS Memory Readout
	0		1	Engineering with AACS Memory Readout
	1		0	Imaging/Playback
	1		1	GS & E

Bits	5	&	4	Engineering Data Rate (bps)
	0		0	10
	0		1	40
	1		0	1200
	1		1	7200 (1200 recorded)

Bits	3	2	1	Engineering Data Mode
	0	0	0	Launch
	0	0	1	Cruise
	0	1	0	Encounter
	0	1	1	TCM
	1	0	0	Special
	1	0	1	Science Maneuver
	1	1	0	CCS Memory Readout
	1	1	1	FDS Memory Readout

Bit 0 Spacecraft ID; 1 = FLT 1, 0 = FLT 2

31-24

Bit Error Tolerance (BET) - Contains the PN bit error tolerance during frame synchronization. (Binary)

23-16

DSN Equipment Configuration - Contains the latest status of any change in station equipment configuration during the time corresponding to the first MF received in this record.

BIT 23-21 =	Receiver (23=MSB)
	001 =	#1
	010 =	#2
	011 =	#3
	100 =	#4
BIT 20-18 =	Subcarrier Demodulator (SDA) (20=MSB)
	001 =	#1
	010 =	#2
	011 =	#3
	100 =	#4
BIT 17-16 =	Telemetry Processor (TPA) (17=MSB)
	00 =	Telemetry Processor (TPA) #1, Symbol Synchronizer (SSA) #1 (TPA #3 at conjoint station)
	01 =	TPA #1 (or 3), SSA #2
	10 =	TPA #2, SSA #3
	11 =	TPA #2, SSA #4

15-0

Receiver Automatic Gain Control (AGC) - Contains the AGC extracted from the GCF block from which the first minor frame received was derived. (Binary)

31-24

DSN Station Number - Contains the identification number of the DSN station originating the data contained in the first minor frame received of this record. (Binary) See page D-12, Item 41.

23-16

Spare

15-0

Estimated Bit Error Count (EBEC) - Count of the number of bits in error, looking at the first 64 bits of each prime MF over N number of frames. The count resets upon frame time domain or DSS change. Placed in header on LAD basis.

Frame Time	Expected Frame Accumulated
.06 sec	15625
.4,.6,1.2,2.4,4.8	1562
9.6,12.0,19.2	156

31-16

Symbol Signal-to-Noise Ratio (SNR) - Contains the symbol SNR extracted from the GCF block from which the first minor frame received was derived. (Binary)

15-0

Decoder SNR - Bit Error Rate out of the Data Decoder Assembly.

31-16

Physical Record Number -

A. For individual EDRs: Unused (set to zeros)
B. For combined EDRs: Physical Record number in binary.

15-8

DQSW - Data Quality Status Word for MF-1 through MF-30.

Station Lock Status
Bit 15 = Unused
Bit 14 = Unused
Bit 13 = Unused
Bit 12 = Receiver
Bit 11 = SDA
Bit 10 = SSA
Bit 9 = MCD
Bit 8 = TPA

7-0

Data Quality Indicators

Bit 7 =	Unused
Bit 6 =	Unused
Bit 5 =	Unused
Bit 4 =	PN Error Outside BET (0=none,1=bit errors exceed BET)
Bit 3 =	PN Error Within BET (0=none, 1=bit errors)
Bit 2 =	Spare
Bit 1 =	Valid Data Flag (0=valid, 1=no data)
Bit 0 =	GCF Block Error (0=no, 1=yes)

31-16

DQSW for MF5-MF12

15-0

DQSW for MF13-MF20

31-24

DQSW for MF21-MF24

23-0

Spare

17-18

31-0

Spare

31-16

Spare

Data Presence

A 4-bit field for data presence indication is supplied for each of the 24 MF to which this header is applied. All 4 bits are set to zero if data is present, otherwise all bits=1.

15-12

DPI for MF 1

11-8

DPI for MF 2

7-4

DPI for MF 3

...

3-0

DPI for MF 22

31-28

DPI for MF 23

27-24

DPI for MF 24

23-0

Spare

26-59

31-0

Spare

31-24

DRS Data Type - Numbers are in HEX.

IRIS = 20	ISR = 29
CRS = 21	DCOM = 2A
LECP = 22	Monitor = 2B
MAG = 23	DCMS = 2E
PLS = 24	ENGE = 2D
PPS = 25	ENGS = 2C
PRA = 26
PWS = 27
UVS = 28

23-0

Spare

Note: For interpretation of day number and hour of day from hour of year, divide the number of hours by 24. The whole number is the day, the remainder is the hour of that day.

Examples:

36 Hours: 36/24 = 1 Remainder 12 = day 1, hour 12 = Jan. 1, 12 PM

3500 Hours: 3500/24 = 145 Remainder 20 = day 145, hour 20 = May 25, 8 PM

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Last modified 12/3/02, Tizby Hunt-Ward
tizby@ftecs.com