Voyager In Space

 

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VOYAGER

Voyager LECP Data Analysis Handbook

 

Data File Descriptions

 

Experiment Data Record (EDR) Format Specification

 

Table C-10, Standard Experiment Data Record Header

 

Item Word Bits Description
1 1 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.
2 1 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 1 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
4 2 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).
5 2 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
6 2 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
7 2 5 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.
8 2 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.
9 3 31-16 Hour of Current Year - Binary hours since the beginning of the current year.  See note following this table.
10 3 15-0 Seconds of Current Hour - Binary seconds since the beginning of current hour.
11 4 31-16 Milliseconds of Current Second - Binary milliseconds
12 4 15-8 Year - Binary year (i.e., 77, 78)
13 4 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
14 4 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
15 4 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
16 5 31-16 Hour of Current Year - Binary hours since the beginning of the current year.  See note at the end of this table.
17 5 15-0 Seconds of Current Hour - Binary seconds since the beginning of the current hour.
18 6 31-16 Millisecond of Current Second - Binary milliseconds.
19 6 15-8 Year - Binary year (i.e., 77, 78)
20 6 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:
21 7 31-16 Hour of Current Year - Binary hours since the beginning of the current year.  See note at the end of this table.
22 7 15-0 Seconds of Current Hour - Binary number of seconds since the beginning of the current hour.
23 8 31-16 Milliseconds of Current Second - Binary milliseconds
24 8 15-8 Year - Binary year (i.e., 77, 78)
25 8 7-4 Spacecraft Event Time Flag - 0=input by NORT file.  1=input by EDR PROC.  Either all 0's or all 1's.
26 8 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.
27 9 31-16 MJS MOD 216 Count Word - Contains the 16-bit MM subcom time word for this record.  Is incremented every 48 minutes.
28 9 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.
29 9 7-0 MJS Line Count Word - Contains the ISS line count which ranges between 1 and 800.  Increments every 0.06 second.
30 10 31-24
31 10 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
32 10 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
33 10 15-8 Effective Rate - Contains the effective bit rate of this data within the downlink telemetry rate.  (Refer to downlink telemetry rate code.)
34 10 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
35 11 31-24 Bit Error Tolerance (BET) - Contains the PN bit error tolerance during frame synchronization.  (Binary)
36 11 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
37 11 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)
38 12 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.
39 12 23-16 Spare
40 12 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
41 13 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)
42 13 15-0 Decoder SNR - Bit Error Rate out of the Data Decoder Assembly.
43 14 31-16 Physical Record Number -

A.  For individual EDRs:   Unused (set to zeros)
B.  For combined EDRs:  Physical Record number in binary.
44 14 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
44 14 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)
45 15 31-16 DQSW for MF5-MF12
46 15 15-0 DQSW for MF13-MF20
47 16 31-24 DQSW for MF21-MF24
48 16 23-0 Spare
49 17-18 31-0 Spare
50 19 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.
51 19 15-12 DPI for MF 1
52 19 11-8 DPI for MF 2
53 19 7-4 DPI for MF 3
... ... ... ...
72 24 3-0 DPI for MF 22
73 25 31-28 DPI for MF 23
74 25 27-24 DPI for MF 24
75 25 23-0 Spare
76 26-59 31-0 Spare
77 60 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
78 60 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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Updated 8/9/19, Cameron Crane

VOYAGER 1 ELAPSED TIME

--:--:--:--
Days: Hours: Minutes: Seconds

*Since official launch
September 5, 1977, 12:56:00:00 UTC

VOYAGER 2 ELAPSED TIME

--:--:--:--
Days: Hours: Minutes: Seconds

*Since official launch
August 20, 1977, 14:29:00:00 UTC

QUICK FACTS

Manufacturer: Voyagers 1 and 2 were built in the Jet Propulsion Laboratory in Southern California.

Mission Duration: 40+ years have elapsed for both Voyager 1 and Voyager 2 (both are ongoing).

Destination: Their original destinations were Saturn and Jupiter. Their current destination is interstellar space.