CASSINI In Space

 

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GALILEO

The Galileo Energetic Particles Detector

 

Galileo EPD Handbook

 

Appendices

 

Appendix E. EPD File Structure (continued)

 

2. Record Header

Source: T. P. Armstrong, March 30, 1985

 

Galileo EPD Record Header Definition

 

This header block will be present in all EPD records.

 

Item Description Type Length
0 Spacecraft Name
  Value Meaning
  'ISPM' International Solar Polar
  'GALI' Galileo
A*4 4
1 Record Descriptor
  Value Meaning
  'EPDH' File Header Record
  'HHSS' Housekeeping and Status Record
  'LMPA' LEMMS Pulse Height Analysis Record
  'PHAR' Pulse Height Archive
  'RATE' Rate Block
A*4 4
2 Production Date
"DD-MMM-YY" Creation Date		 A*10 10
3 File Type
  "AV"=EPD Average
  "AR"=EPD Archive
A*2 2
4 Procedure Name A*6 6
5 Procedure Version I*2 2
6 Time of First Data Occurrence
  Array # Description
 1 Year
 2 Day
 3 Hour
 4 Minute
 5 Second
I*2 10
7 Time of Last Data Occurrence
(see expl. of item #6)		 I*2 10
8 Instrument Status Block (report of voltages, temperatures, and digital status flags) I*4 TBD
9 Magnetic Field Data
  Coordinates: Payload
  Variable: BDATA(64,4)
  First Index: Labels up to 64 repetitions of magnetic field data in each record. This is included to give maximum time resolution in subsequent pitch and phase angle calculations as per the request of DJW 4/24/84.

  Second Index:
 1
 2
 3
 4

 Contents
Bx
By
Bz
# samples		 Units
nanotessla
nanotessla
nanotessla
  
R*4 6
10 Ephemeris Block

Heliocentric Inertial Cartesian States (x, y, z, vx, vy, vz--km & km/sec) of:
   a.) Spacecraft
   b.) Earth
   c.) Jupiter

Jovicentric Mean Orbit Cartesian States (x, y, z, vx, vy, vz--km & km/sec) of:
   d.) Spacecraft
   e.) Io
   f.) Europa
   g.) Ganymede
   h.) Callisto

Jovicentric Magnetic Axis System III Spherical Coordinates (r, theta, phi) of:
   i.) Spacecraft
   j.) Io
   k.) Europa
   l.) Ganymede
   m.) Callisto

 R*4 TBD
11 Orientation Block
  Transformations from:
   a.) Payload to SCC. (SCC--spacecraft centered corotation)
   b.) Payload to Heliocentric
   c.) Payload to System III
   d.) Payload to Inertial
   e.) Payload to B field		 R*4 TBD
12 Sector Block

 THETA(60,8,2) Polar angle of 60 sectors in 8 steps
 for B field coords. (1) and SCC (2)
 PHI(60,8,2) Azimuth angle of 60 sectors in 8 steps
 for B field coords. (1) and SCC (2)
 BMAG(60,8) Magnitude of B field for 60 sectors and 8 steps

 R*4 TBD
13 Stepping Block
    Variable: ISTEP(12)
     Type: I*4
     Index Contents
1 Step position for this record (0-7)
2 Step position for former record (0-7)
3 Next expected step position (0-7)
4 Position expected in next record (0-7)
5 Direction of step movement:
   +1 = increasing
   0 = this record is from a turn
   -1 = decreasing
6 Minimum sector of scan (0-7)
7 Maximum sector of scan (0-7)
8 Dwell time (milliseconds) per step
9 Slew rate (millidegrees/second)
10 Spare
11 Spare
12 Spare
   
14 Spares -- TBD
15 Number of Physical Records in this Logical Record I*2 2
16 Index of this Physical Record

Explanation of items 15 and 16:  For record types of length small enough to fit into the fixed (defined) number of bytes for an EPD record, the blocking factor will be 1:1. That is, item #14 = 1 and item #15 = 1. For large logical records which would necessarily span several physical records, item #14 gives the blocking factor, say 8 for 8:1, and item #15 tells which of the 8 possible records this one is.

 I*2 2

 

 

Next: 3. Rate Block 

 

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Updated 8/23/19, Cameron Crane

QUICK FACTS

Manufacturer: The Galileo Spacecraft was manufactured by the Jet Propulsion Laboratory, Messerschmitt-Bölkow-Blohm, General Electric, and the Hughes Aircraft Company.

Mission Duration: Galileo was planned to have a mission duration of around 8 years, but was kept in operation for 13 years, 11 months, and 3 days, until it was destroyed in a controlled impact with Jupiter on September 21, 2003.

Destination: Galileo's destination was Jupiter and its moons, which it orbitted for 7 years, 9 months, and 13 days.