VOYAGER

Voyager LECP Data Analysis Handbook

 

Data File Descriptions

 

Experiment Data Record (EDR) Format Specification

 

Cruise 7 (Cruise 5a)

 

2 April 1981

 

Dr. S. M. Krimigis
Johns Hopkins University
Applied Physics Laboratory
Johns Hopkins Road
Laurel, Maryland 20810

Dear Dr. Krimigis:

 

Attached is a rough draft of the proposed EDR format for Cruise 7 (CR-7) telemetry data. This attachment describes only the LECP subheader and science data block. The standard EDR header will be used. The CR-7 format is intended to closely follow that for CR-5 with modifications made to allow for the different timing and data cycling in CR-7.

 

Please have your cognizant personnel review this material by April 17. I will be contacting each group by telephone prior to that date to discuss any questions that may arise.

 

Please feel free to call me at FTS 792-7840.

 

Sincerely,

 

David Wagner

 

DW:pp
Encl.
cc:
T. Armstrong
R. Collins
E. Franzgrote
G. Gloeckler
E. Keath
L. Lanzerotti
A. Sacks
C. Stembridge
E. Stone
H. Woo

 

---

 

 618-306, CR-7, Revision D, Change 3

 

10.3 Low Energy Charged Particle (LECP) Experiment

 

The LECP EDR science physical record consisting of 24 CR-7 MFs corresponds to a 19.2 minute measurement period which is equivalent to three LECP instrument data cycles.

 

The LECP CR-7 EDR physical record structure is shown in Figure 10.3-1 and the physical magnetic tape organization is shown in Figure 10.3-2

.

Figure 10.3-1, LECP Science Physical Tape Records

 

Standard Header (60-Words)

Subheader (8-Words)

Data Block (384-Words)

24 MF 19.2 MIN 452 Words

 

All Words 32-Bits

 

One physical record contains a standard EDR header followed by the LECP peculiar subheader and data block for 24 CR-7 telemetry frames.

 

One physical record contains 3 instrument cycles.

 

Figure 10.3.2 Physical Magnetic Tape Configuration for EDR Cruise 7.

 

Figure 10.3-3 defines the structure and the contents of the LECP CR-7 EDR science record subheader. Figure 10.3-4 defines the structure and contents of the LECP CR-7 EDR science data block. The standard CR-7 EDR header is specified in Appendix C.

 

Figure 10.3-3, LECP Science Subheader Format

 

EDR Word	Bits
	31	15              0	31	15            0
1	LECP CMD 1 MF 1	LECP CMD 2 MF 14	LECP CMD 3 MF 22	Spare
2	Spare		Spare
3	Spare		Spare
5	Spare		Spare

 

Total block length is 8 (32-bit) EDR words (24 MF; 1 to 3 LECP CMD words).

 

MF 1 is in:

 

SCT 60 = 0,24,48 when MOD 216 is even;
SCT 60 = 12,36 when MOD 216 is odd.

 

Figure 10.3-4, LECP EDR Science Logical Record Format

 

MF	EDR Word	Bits
		31     16   15        0   31      16   15      0
1	1	P1	P2	P3	P4
1	3	P5	P6	P7	P8
1	5	P9	P10	P11	P12
1	7	P13	P14	P15	P16
1	9	R1	R2	R3	R4
1	11	R5	R6	R7	R8
1	13	R9	R10	R11	R12
1	15	R13	R14	R15	R16
2	17	P1	P2	P3	P4
:	:	:	:	:	:
24	383	R13	R14	R15	R16

 

P = PHA Word
R = Rate/Status Word

 

Logical record length is 384 (32-bit) EDR words equivalent to 24 MF or 768 LECP 10-bit words.

 

MF 1 is in:

 

SCT 60 = 0,24,48 when MOD 216 = EVEN;
SCT 60 = 12,36 when MOD 216 = ODD.

 

 

Return to EDR main page.

Return to Data File Descriptions main page.

Return to Voyager LECP Data Analysis Handbook Table of Contents.
Return to Fundamental Technologies Home Page.

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

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