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Reduced Short Time Averages of 116-cm Bistatic Radar Lunar Observations


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

Time span: 1972-04-23 to 1972-04-23


This data set, referred to by the experimenter as JM Doptrack tapes, is a complete set of reduced, short-time averages of the electromagnetic wave spectra for 116-cm bistatic radar observations of the moon. This data set was received from the experimenter and is on binary magnetic tape written in XDS Sigma 5 machine images. These data have been corrected for instrumental effects, but are unedited. The data set includes observations merged with trajectory data and certain ancillary data computed from the trajectory. Each tape file contains a header record followed by many data records. The header record includes a file identifier, the date the data were taken, the time increment between the midpoints of each data averaging frame, and the number of records following the header record. The data are grouped in frames of 6 records each, the first 5 records containing observational data and the sixth record containing ephemeris data. The 5 data records in each frame contain elements of the coherency matrix, J. Record 1 contains J11(k), record 2 contains J22(k), record 3 contains the real part of J12(k), record 4 contains the imaginary part of J12(k), and record 5 contains the fractional polarization of the received signal. Record 6 of each data frame list UT2 at the midpoint of the frame, the reflected Doppler shift minus the direct Doppler shift, the predicted bandwidth for an rms surface slope of .01, the angle of incidence, the spacecraft altitude and speed, the radar cross-section predicted for a smooth, conducting moon, the radar cross-section divided by the received power, and the components of selenographic unit position vectors for the position and velocity of the spacecraft, the vector for the position of the specular point, and the vector from the center of the moon to the center of the earth. Also included are the selenographic latitude and longitude for the spacecraft and specular point positions, the component of the Doppler shift due to the earth's rotation, the total Doppler shift of the reflected signal, the speed of the specular point on the surface of the moon, the vehicle look angle to earth, and the Euler angles of local horizon coordinates.

Alternate Names

  • 116-cm Bistatic Radar Lunar Obs.
  • JM Doptrack Tapes (116 CM)


  • Planetary Science: Geology and Geophysics


  • 72-031A-12B

Additional Information



Questions and comments about this data collection can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Prof. G. Leonard TylerData ProviderStanford
Prof. G. Leonard TylerGeneral ContactStanford
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