File: P10HVMMN_FMT.txt Version: NSSDC 12/22/98 JFC =============================================================================== PIONEER 10 INTERPLANETARY MAGNETIC FIELD DATA - 1 MINUTE AVERAGES ----------------------------------------------------------------- Data Set Coverage (yyyy-mm-dd): 1972-03-03 to 1975-11-17 NSSDC Data Set ID: 72-012A-01J Data Set Contact: Joyce Wolf, NASA JPL Experiment: Pioneer 10 Helium Vector Magnetometer (HVM) Principal Investigator: Dr. Edward J. Smith, NASA JPL Data Set Description: This data set from the Pioneer 10 Helium Vector Magnetometer (HVM) consists of one minute averages of vector components and scalar magnitudes of the interplanetary magnetic field. The three components (Br, Bt, Bn) are given in the RTN coordinate system and all magnetic fields are expressed in nanotelsa units. The scalar magnitudes (B) are averages of higher resolution scalar magnitudes. The time tag for each one-minute interval is the midpoint of the averaging interval in SCET-UT (Spacecraft Event Time - UT). The averages were originally calculated over one-minute intervals in Ground Received Time, and the midpoints have been converted to SCET-UT. The file P10_LIGHTTIME contains daily values for the one-way light-time delay. No records are written for data gaps. Most files cover 28 or 35 days, but there are a number of shorter files, particularly at year boundaries. Data for the Jupiter encounter, days 329-349 of 1973, are not included. The RTN system is fixed to the sun-spacecraft line and aligned with the solar heliographic equator. The R axis is the radial direction to the spacecraft, the T axis is the cross product of the solar rotation axis and the R axis, and N is the cross product of R and T. The file P10HVM_15M.SFD 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 72-012A-01I for 15-minute averaged data covering 1972-03-03 to 1975-11-17. Data Set Files: P10HVMMN_FMT.txt - this document (ASCII) P10HVM_15M.SFD - SFDU metadata extract from Pioneer 10 HVM 15-min. data set Myyddd.asc - 1-minute data files from Pioneer 10 HVM starting at date yyddd P10_LIGHTTIME.asc - data file with one-way light-time delays (ASCII) Data Format for File Myyddd.ascii: IY - SCET-UT Year (yy) IDOY - SCET-UT Day of Year (ddd) , IDOY = 1 for Jan. 1 IHR - SCET-UT Hour of day IMIN - SCET-UT Minute of hour ISEC - SCET-UT Second of minute 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 The data records are read in ASCII FORTRAN format as follows: READ(10,110) IY, IDOY, IHR, IMIN, ISEC, BR, BT, BN, B 110 FORMAT(1X,I2,I4.3,3I3.2, 4F8.4) 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. Pioneer data on NDADS (NASA's Data Archive and Distribution Service) may be located on the WWW via the SPyCAT service at the above URL or an e-mail message to ARMS (Automated Retrieval Mail System) at archives@ndadsa.gsfc.nasa.gov with "HOLDINGS" on the subject line. 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.