File: P11HVMHR_FMT.txt                            Version: NSSDC 11/15/2001 JFC
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PIONEER 11 INTERPLANETARY MAGNETIC FIELD DATA - 1 HOUR AVERAGES
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Data Set Coverage (yyyy-mm-dd): 1973-04-06 to 1992-08-01

NSSDC Data Set ID: 73-019A-01I

Data Set Contact: Joyce Wolf, NASA JPL

Experiment: Pioneer 11 Helium Vector Magnetometer (HVM)

Principal Investigator: Dr. Edward J. Smith, NASA JPL

Data Set Description:

The Helium Vector Magnetometer (HVM) measurements of interplanetary magnetic
fields are averaged at one-hour intervals with respect to Spacecraft Event Time
- UT. Data set parameters include the three orthogonal components of the
magnetic field in RTN coordinates, where R is in the sun-s/c direction, T is
the cross product of the solar rotation axis and R, and N is the cross product
of R and T. The hourly field magnitude, averaged over scalar magnitudes at
higher time resolution, is also provided. All field values are in nanotelsa. 

The file P11HVM_15M.sfdu provides a detailed description of the Pioneer
spacecraft, the HVM experiment, and the data. This ASCII document is written in
Standard Formatted Data Unit (SFDU) format as part of NSSDC data set
73-019A-01H for 15-minute averaged data covering the same time interval.
Unlike the 1-hour data set here, the 15-min. data set gives times as Ground
Received Time - UT and the coordinate system switches to Pioneer Ecliptic in
1976 and thereafter.

Data Set Files:

P11HVMHR_FMT.txt - this document
P11HVM_15M.sfdu  - SFDU metadata extract from Pioneer 11 HVM 15-min. data set
P11HVMyy.asc     - Hour average data files (ASCII) for year 19yy

Data Format for File P11HVMyy.asc:

IY 	- SCET-UT Year (yy)
IDOY	- SCET-UT Day of Year (ddd) , IDOY = 1 for Jan. 1 
IHR	- SCET-UT Hour of day
BR      - Radial component (RTN system) of vector magnetic field in nT
BT      - Transverse component (RTN) of vector magnetic field in nT
BN	- Normal component (RTN) of vector magnetic field in nT
B	- Scaler magnetic field magnitude in nT
RAU     - Radial distance from Sun to spacecraft in AU
ELAT    - Ecliptic latitude of spacecraft in degrees
ELON    - Ecliptic longitude of spacecraft in degrees

The following FORTRAN read statement will read the hourly data records:

      READ(10,10) IY, IDOY, IHR, BR, BT, BN, B, RAU, ELAT, ELON
10    FORMAT(I3, I4, I3, 4F9.4, F9.5, F7.1, F8.1)

Related Information and Data:

Further details on the spacecraft, experiment, data sets at NSSDC, and related
WWW sites can be found on the Pioneer 10/11 flight project page under

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

Hour averages of the interplanetary solar wind data from, and hourly heliocentric
coordinates of, Pioneer 10/11 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.