File: HE1MGB_FMT.txt                       Version: NSSDC 09/13/2000 JFC
 ------------------------------------------------------------------------------

 HELIOS 1 INTERPLANETARY MAGNETIC FIELD DATA FROM THE NEUBAUER ET AL 
 EXPERIMENT

 Time Coverage: 1974-12-10 to 1979-06-30

 Principal Investigator: Fritz M. Neubauer
                         Institute of Geophysics
                         University of Koln
                         Albertus-Magnus-Platz
                         50923 Koln, Germany
                         Phone: 49-221-4702310
                         Email: neubauer@geo.uni-kochr.de

 Data Files: HE1MGByy.asc for data from year 19yy. 

 Data Parameter Description:

  NY      - YEAR OF THE DATA INTERVAL (LAST TWO DIGITS ONLY). 
  ND      - DAY OF THE DATA INTERVAL FROM THE FIRST DAY OF THE ABOVE YEAR,  
            JAN. 1= DAY 1.  
  NH      - HOUR OF THE DAY OF THE DATA INTERVAL.                      
  BXSE    - THE COMPONENT OF THE INTERPLANETARY MAGNETIC FIELD 
            DIRECTED TOWARD THE SUN AND PARALLEL TO THE X-AXIS OF THE
            SPACECRAFT-CENTERED SOLAR ECLIPTIC (SSE) COORDINATE SYSTEM 
            (FIELD IN NANOTELSAS). 
  BYSE    - THE COMPONENT OF THE INTERPLANETARY MAGNETIC FIELD
            IN THE ECLIPTIC ALONG THE SSE Y-AXIS.
  BZSE    - THE COMPONENT OF THE INTERPLANETARY MAGNETIC FIELD DIRECTED
            PERPENDICULAR TO AND NORTHWARD FROM THE ECLIPTIC, PARALLEL TO
            THE SSE Z-AXIS.
  BMAG    - AVERAGE OF FINE SCALE FIELD MAGNITUDES FOR THE INTERPLANETARY
            MAGNETIC FIELD VECTOR (NANOTESLAS).
  THETA   - ELEVATION ANGLE OF THE MAGNETIC FIELD VECTOR IN THE SSE SYSTEM
            (I.E., SSE LATITUDE ANGLE).
  PHI     - AZIMUTH ANGLE OF THE MAGNETIC FIELD VECTOR IN THE SSE SYSTEM
            (I.E., SSE LONGITUDE ANGLE).

 NOTE: THE SSE SYSTEM IS ANALOGOUS TO THE GEOCENTRIC SOLAR ECLIPTIC 
 SYSTEM IN THAT THE X-AXIS POINTS FROM THE CENTRAL BODY (THE SPACECRAFT) 
 TOWARDS THE SUN, THE Y-AXIS POINTS OPPOSITE TO ORBITAL MOTION IN THE 
 ECLIPTIC, AND THE Z-AXIS POINTS NORTH FROM THE ECLIPTIC.  THE HELIOS 1/2
 SPACECRAFT HAD ORBITS IN THE ECLIPTIC WITH SPIN AXES PERPENDICULAR TO 
 THE ECLIPTIC. SINCE THERE WERE TWO HELIOS SPACECRAFT, WE REFER TO THE 
 SPACECRAFT-CENTERED (RATHER THAN HELIOS-CENTERED SOLAR ECLIPTIC ) SYSTEM
 TO ELIMINATE ANY POSSIBLE CONFUSION. 

 File Parameter Format:

          WRITE(20,120) NY,ND,NH,BXSE,BYSE,BZSE,BMAG,THETA,PHI
 120      FORMAT(1X,I2,1X,I3,1X,I2,3F8.2,F6.1,2F7.2)

 Data Source: Extracted from on-line version of NSSDC dataset 74-097A-01C 
 (identical to 74-097A-09B) in directory MGD_FREEMAN with code READHEL.fortran.

 Reference: 

     G. MUSMANN, F. M. NEUBAUER AND E. LAMMERS, RADIAL VARIATION OF 
     THE INTERPLANETARY MAGNETIC FIELD BETWEEN 0.3 AND 1.0 AU: 
     OBSERVATIONS BY THE HELOIS 1 SPACECRAFT, J. GEOPHYS.,42,591-598, 
     1977. 


Related Information and Data:

Further details on the spacecraft, experiment, data sets at NSSDC, and 
related WWW sites can be found on the Helios 1/2 flight project page under

http://nssdc.gsfc.nasa.gov/space/

Hour averages of the interplanetary solar wind data from, and hourly 
heliocentric coordinates of, Helios 1/2 and other interplanetary 
spacecraft may be also be accessed and plotted on-line through the 
COHOWeb service based at the same WWW site as above.

Acknowledgement:

Use of these data in publications should be accompanied at minimum by
acknowledgements of the National Space Science Data Center and the 
responsible Principal Investigator defined in the experiment 
documentation provided here. Citation of NSSDC's Coordinated Heliospheric
Observations (COHO) data base would also be appreciated, so that other 
potential users will be made aware of this service.