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Ulysses HISCALE Data Analysis Handbook

 

Chapter 2: HISCALE Data File Descritions and Overview

 

Chapter 2.2: Experiment Data Record (continued)

 

2.2.8 Data Specifications for HISCALE/EPAM Conversion of ARCGEN

 

From “Overview of HISCALE/EPAM Data Processing,” by Gene Holland, August 1997

 

Files relating to ARCGEN processing:

 

Input Files 1. EDRyyddd_02.00
2. Lanmerge.par
3. IDF.dat
4. UMAGyyddd.dat
5. NAVyyddd.dat
Output Files 1. ERRyyddd.log
2. DPIyyddd.dat
3. IULAyyddd.rat
4. IULAyyddd.pha

 

Input File Specifics:

 

Definitions:
Essential data is defined as bits which play a significant role in level 2 data computations. The data referenced is defined as nonessential if the bits accessed are determined to play a nominal role in level 2 data computations.

 

Byte Description Note:
When describing a byte, bit 0 is the leftmost bit, or most significant bit (MSB), bit 7 is the rightmost bit or least significant bit (LSB).

 

Input File #1. EDRyyddd_02.00

  

(For Input Files #2-5, click here.)

 

File Type: Sequential
Record Type: Fixed Length
Record Size: 124 (SFDU Header) + 7168 (LAN Data Block) = 7292 bytes

 

Byte
1                   124		 125                         7292

SFDU 
HEADER

LAN EDR
DATA BLOCK

 

LAN EDR Data Block is representative of two LAN Logical Records (5120 bytes) plus the 2048 bytes of corresponding S/C ID, Instr. H/K, etc. For the format of the LAN EDR Data Block refer to reference 3.

 

SFDU Header References:

 

Word Bits  
3 0-7 Bit Description: Major Data Class
ARCGEN Specifications:
Importance to Processing: Nonessential
References: Getlan.f - line 451
Purpose of Reference: Selection structure - data integrity flag of Getlan/EDRchk subroutine
EDR Identifier: 00000101
EPAM Status: TBD
As of 1/7/97 no equivalent identifier is known to exist for ACE. Therefore, taking into consideration the non-essential role of this data in ARCGEN processing, the Ulysses identifier will be used until a comparable ACE identifier is known.
3  8-15 Bit Description: Minor Data Class
ARCGEN Specifications:
Importance to Processing: Nonessential
References: Getlan.f - line 456
Purpose of Reference: Selection structure - data integrity flag of Getlan/EDRchk subroutine
LAN Identifier: 00000110
EPAM Status: TBD
As of 1/7/97 no equivalent identifier is known to exist for EPAM. Therefore, taking into consideration the nonessential role of this data in ARCGEN processing, the HISCALE identifier will be used until a comparable EPAM identifier is known.
3 16-31  
4 0-31 Bit Description: Spacecraft Event Time - UTC that corresponds to the first valid minor frame in the EDR. Consists of a 4-byte coarse time (seconds since the beginning of Jan. 1st, 1950, 00:00 a.m.) and a 2-byte fine time (fraction of current second).

Word 3

Word 4
Bits: 16-23 24-31 0-7 8-15

 

Binary Coarse Time: 00000000 00000000 00000000 00000000

 

Word 4
Bits: 16-23 24-31

 

Binary Fine Time: 00000000 00000000

 

ARCGEN Specifications:
Importance to Processing: Essential
References: Getlan.f - line 391; Getlan.f - line 212,213
Line 319 - Purpose of Reference: Write current S/C Event Time to monitor.
Lines 212, 213 - Purpose of Reference: Variable assignments

EPAM Status: TBD
The ACE Science Center at Caltech is planning on providing the necessary functions to determine this time from the S/C Clock. As of 1/8/97 these functions have not been received. Until these functions are provided a “best estimate” of this time will be used based upon the date of launch and S/C Clock. Of further note, the S/C Clock value provided within the EPAM Level 1 Structure corresponds to the beginning of the data collection cycle, not the first valid minor frame within the cycle. This may pose as a discrepancy between the HISCALE SCET and the EPAM equivalent.
6 29, 30 Bit Description: Mission Mode Flags
 

Bit 29: Spacecraft Clock Flag
Indicates if spacecraft clock is valid or not.
0 = SCLK valid
1 = SCLK is missing, incomplete, or invalid

ARCGEN Specifications:
Importance to Processing: Nonessential
References: Getlan.f - line 496
Purpose of Reference: Selection structure contained within Getlan/Seqchk which determines whether the S/C Clock should be extracted from the current EDR (word 9 0-31, 10 0-15), or computed using the current telemetry mode.
EPAM Status: Not Available
It is assumed that the S/C Clock will remain valid for the entirety of the ACE mission. Therefore each EPAM EDR Record will have a 0 placed at word 6, bit 29, indicating a valid S/C Clock.

 

Bit 30: Spacecraft Event Time Flag
Indicates if SCET value is valid or not
0 = SCET is valid
1 = SCET is missing, incomplete, or invalid

ARCGEN Specifications:
Importance to Processing: Nonessential
References: Getlan.f - line 211
Purpose of Reference: Selection structure which determines whether to define scet, scetm variables by accessing words 3, 4 of the SFDU header, or by a telemetry rate computation.
EPAM Status: Not Available
A SCET flag will not be available. Therefore word 6, bit 30 of each EPAM EDR record will be set to zero and defined as a filler bit.

7 0-7 Bit Description: Mission ID
ARCGEN Specifications:
Importance to Processing: Nonessential
References: Getlan.f - line 444
Purpose of References: Selection structure in Getlan/EDRchk used for routine data integrity check.
Ulysses Mission ID: 00000011
EPAM Status: OK
ACE Mission ID: 0001011100 - note 10 bit length
EPAM ARCGEN will replace the Ulysses Mission ID flag with the corresponding ACE Mission ID.
9 0-31  
10 0-15 Bit Description: Spacecraft Clock
Indicates current value of the spacecraft clock. Word 9 reflects the actual clock value from spacecraft telemetry. Word 10, bits 0 - 15 are the fractional portion expressed as a binary integer.
ARCGEN Specifications:
 Importance to Processing: Essential
References: Getlan.f - lines 267-268, 501
Purpose of References: Variable Assignments
EPAM Status: OK
The S/C Clock time is provided within the EPAM Level 1 Data Structure. It should be noted that the time provided within the EPAM Level 1 Data Structure corresponds to the 4-Format Pulse, not necessarily the first valid minor frame within the data collection cycle, whereas for HISCALE this time represents the first valid minor frame within the data collection cycle.
11 16-19 Bit Description: Format Identifier
 0000 Engineering - 64 bps
0001 Scientific - 128 bps
0010 Scientific - 256 bps
0011 Scientific - 512 bps
0100 Engineering - 1024 bps
0101 Scientific - 1024 bps
ARCGEN Specifications:
 Importance to Processing: Essential
References: Getlan.f - line 461
Purpose of Reference: Accessed in Getedr/EDRchk to acquire current telemetry mode for the EDR record. Currently requires Scientific Format Identifier of 128, 256, 512, or 1024 bps.
EPAM Status: OK
For HISCALE ARCGEN the main purpose of acquiring the telemetry mode is to determine data accumulation timing intervals. For EPAM, data accumulation is not dependent upon the telemetry rate, but is instead collected by the C & DH Component at a constant 168 bps rate. This 168 bps rate only contains EPAM data and therefore yields one minor frame of EPAM digital science data per second. This is equivalent to the HISCALE telemetry (accumulation) rate of 1024 bps. The strategy for EPAM is to set bits 16-19 of word 11 to zero and define them as filler bits. Further, ARCGEN itself will be revised, changing all references of the telemetry mode to a constant 168 bps rate.
11 24-31  
12 0-15 Bit Description: Record Creation Date
 Word 11, bits 24-31 Year (year minus 1900)
Word 12, bits 0 - 15 Day (day of year)
Example: For EDR97054_02.00
Word 11, bits 24-31 - 97
Word 12, bits 0 - 15 - 71
ARCGEN Specifications:
 Importance to Processing: Nonessential
References: Getlan.f - line 266, 268
Purpose of References: Write creation date to monitor
EPAM Status: OK
EPAM EDR generator will create the necessary record creation dates.
12 16-31 Bit Description: Bit Error Rate
Summation of the number of sync word errors detected in 105 bits of frame sync words displayed as a percentage.
ARCGEN Specifications:
 Importance to Processing: Nonessential
References: Getlan.f - line 291
Purpose of Reference: Variable Assignment
EPAM Status: TBD
The sole purpose of the bit error rate variable assignment is to write this information to the DPIyyddd.dat files. Therefore the acquisition of this data plays a nominal role in the overall objectives of ARCGEN processing. If an EPAM equivalent is not available, references to this data will be “commented out” in the EPAM version of ARCGEN, and EPAM EDR bits 16-31 of word 12 will be set to 0.
13 0-15 Bit Description: Symbol Signal to Noise Ratio
The symbol SNR from the GCF block from which the first minor frame of the current record was derived (binary).
ARCGEN Specifications:
 Importance to Processing: Nonessential
References: Getlan.f - line 292
Purpose of Reference: Variable Assignment
EPAM Status: Not Available
The sole purpose of the symbol signal to noise ratio variable assignment is to write this information to the DPIyyddd.dat files. Therefore the acquisition of this data plays a nominal role in the overall objectives of ARCGEN processing. References to this data will be “commented out” in the EPAM version of ARCGEN, and EPAM EDR bits 0-15 of word 13 will be set to 0.
13 16-31 Bit Description: Receiver Automatic Gain Control (AGC)
AGC extracted from the GCF block from which the first minor frame of the current record was derived.
ARCGEN Specifications:
 Importance to Processing: Nonessential
References: Getlan.f - line 292
Purpose of Reference: Variable Assignment
EPAM Status: TBD
The sole purpose of the AGC variable assignment is to write this information to the DPIyyddd.dat files. Therefore the acquisition of this data plays a nominal role in the overall objectives of ARCGEN processing. If an EPAM equivalent is not available, references to this data will be “commented out” in the EPAM version of ARCGEN and EPAM EDR bits 16-31 of word 13 will be set to 0.
14-21 0-31 Bit Description: Data Presence Indicator (DPI) Flags
32 status flags indicating whether minor frames 0-31 are present in this record. Word 14 contains DPI flags for minor frames 0-31, word 15 contains DPI flags for minor frames 32-63, etc.
0 = data present
1 = all or part of minor frame missing
ARCGEN Specifications:
 Importance to Processing: Essential
References: Getlan.f - line 139, 290, 293
Purpose of References: Variable Assignments. The DPI flags are then used within data validity selection structures in MFSA.f, PHA.f, Timelan.f. (This is a non-inclusive list.)
EPAM Status: TBD
As of 7/7/97 it is assumed that the EPAM QAC data is equivalent to the HISCALE DPI flags, but this needs to be verified.
22-29 0-31 Bit Description: GCF Block Error Correction Indicator (ECI)
 Flags. 32 status flags indicating whether the GCF block from which minor frames 1 - 32 were derived was received in error. Word 22 contains ECI flags for minor frames 0 - 31, Word 23 contains ECI flags for minor frames 32 - 63, etc.
0 = no errors
1= error flagged
ARCGEN Specifications:
 Importance to Processing: Nonessential
References: Getlan.f - line 294
Purpose of Reference: Variable Assignment
EPAM Status: TBD
The sole purpose of the ECI variable assignment is to write this information to the DPIyyddd.dat files. Therefore the acquisition of this data plays a nominal role in the overall objectives of ARCGEN processing. If an EPAM equivalent is not available, references to this data will be “commented out” in the EPAM version of ARCGEN and EPAM EDR bits 0-31 of words 22-29 will be set to 0.
30 0-31  
31 0-15 Bit Description: Spin Phase, time from last sun crossing of Spacecraft x-axis.
Configuration for Units of Seconds:

Word 30

Word 31
Bits: 0-7 8-15 16-23 24-31 0-7 8-15
00000000 00000000 00000000 00000000 00000|000 00000000

Exponent

   Mantissa

Note: Spin Reference Pulse must be less than 231 seconds; therefore bits 0-5 of word 30 are filler bits.
ARCGEN Specifications:
 Importance to Processing: Essential
References: Getland.f - line 246, 264
Purpose of References: Variable Assignments
EPAM Status: Not Applicable
The purpose of the ARCGEN reference of the sun reference pulse is to calculate the first spin time. This calculation is an estimation, and is necessary for HISCALE processing which lacks direct access of sun pulse times. For EPAM, each sun pulse time is latched and placed within minor frames 0 and 8 of the EPAM Science format (instrument bit stream), therefore making the ARCGEN calculation obsolete. As such, determination of which sun pulse time corresponds to the first spin time will be determined within EPAM EDRGEN. Furthermore, this time will be placed within the EPAM SFDU Header, and the first spin time algorithm within EPAM ARCGEN will be “commented out.”

 

Refer to Tables 2.6 - 2.11 for definitions of all 124 bytes of the EDR SFDU Header.

 

 

Next: Section 2.2.8 Continued

 

Return to Chapter 2 Table of Contents

Return to Ulysses HISCALE Data Analysis Handbook Table of Contents


Updated 8/8/19, Cameron Crane

QUICK FACTS

Manufacturer: ESA provided the Ulysses spacecraft, NASA provided the power supply, and various others provided its instruments.

Mission End Date: June 30, 2009

Destination: The inner heliosphere of the sun away from the ecliptic plane

Orbit:  Elliptical orbit transversing the polar regions of the sun outside of the ecliptic plane