NASA Logo, National Aeronautics and Space Administration
NASA Space Science Data Coordinated Archive Header

Imaging Photopolarimeter Polarization Data


Availability: At NSSDC, Ready for Offline Distribution (or Staging if Digital)

Time span: 1973-05-31 to 1976-10-29


This data set is polarization data from the Imaging Photopolarimeter experiment (IPP) on the Pioneer 10 and 11 missions. The data are on BCD, unblocked with variable length, magnetic tape. A copy of the CDC 6400 program COPTAV, used to generate the tape, accompanies them. Tables 1 and 2 provide lists of Pioneer 10 and 11 observations (day/yr), the number of 4-roll data sets (each set of which may yield a polarization solution), and the number of sectors/roll (SECT). Each sector consists of four words (channels BP, BS, RP, RS). These tables also list the tape files and object observed for each day. The record length varies as 4* SECT. Each observing day consists of two files: (1) the header record (similar to that found on the EDR) with indication whether original EDR data have been edited or not ("edited PLUM run" or "PLUM run", respectively) prior to being averaged by the program PLUM and (2) the data file consisting of 2-record sets, the spacecraft altitudes (A-B4) in the first record, spacecraft (EDR) housekeeping, and the data (C-M subscript 56) in the second record. The second record length may vary from day to day as a function of 4* SECT (Table 1). Each dual record set pertains to data averaged over a single aperture (word 81 of the housekeeping data). A polarimetric solution is computed from an 8-record set with records 2, 4, 6, and 8 containing data for apertures 0.5 mr, lambda/2, DP, and 8 mr (records 4, 5, 6, 4 respectively). Table 3 equates parameters A-M found in COPTAV with the conventional names or mnemonics given in Pioneer documentation. The tape contain the same kind of information as the PLUM microfiche data sets (72-012A-07B and 73-019A-07B), except they do not contain the standard deviations for intensities included in the PLUM microfiche. It is recommended that the PLUM microfiche be used if possible.

Alternate Names

  • Polarization Data


  • Planetary Science: Atmospheres
  • Planetary Science: Small Bodies
  • Astronomy: Visible
  • Planetary Science: Geology and Geophysics


  • 73-019A-07F

Additional Information



Questions and comments about this data collection can be directed to: Dr. John F. Cooper



NameRoleOriginal AffiliationE-mail
Ms. Lonny L. BakerGeneral ContactUniversity of Arizona
[] NASA Logo -