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Hourly Averaged Solar X-ray Fluxes on Microfilm


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

Time span: 1967-07-29 to 1968-07-15


This collection, on 16-mm microfilm, was generated at NSSDC from data set SOXR-00055. It contains hourly averaged solar X-ray fluxes obtained using two different filtering techniques identified as method H and method D. The data are divided into two subsets, one corresponding to each filter.

The data filtered using method H were considered in hourly blocks of universal time. The means and standard deviations of the fluxes observed for each detector were calculated for each 1-hour interval. Data points differing from the mean by more than +2.5 or -3 sigma were deleted, and the means and standard deviations were again calculated. This process was iterated with the limits being reduced until, for the fourth pass, the limits were +1 and -1.5 sigma. The remaining points were used to calculate the hourly averages and standard deviations shown on the tape. This method eliminated data for small flares and trapped-particle contamination from the radiation belts but did not eliminate data from large flares or trapped-particle contamination from the South Atlantic anomaly.

Method D was similar to method H except that the data were treated in daily intervals rather than hourly intervals. The daily average fluxes and standard deviations were calculated and used in the filtering process described above to eliminate flare data and particle contamination. This method eliminated almost all data from flares and trapped particles, including those in the South Atlantic anomaly. The listing contains the year, month, day, and the starting hour (universal time) of the hourly data sample averaged (an hour value of 25 indicates a daily average), the hourly average fluxes in ergs/(sq cm-s), and standard deviations for the 0.05-0.3 nm, 0.1-0.8 nm, 0.8-2 nm, and 4.4-6 nm detectors.

Alternate Names

  • Hourly Avg Solar X-Ray Flux,Mfilm


  • Solar Physics: X-Ray


  • 67-073A-21C

Additional Information



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



NameRoleOriginal AffiliationE-mail
Dr. Donald M. HoranGeneral ContactUS Naval Research
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