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Hourly Averaged Solar X-ray Fluxes


Availability: Archived at NSSDC, accessible from elsewhere

Time span: 1967-07-29 to 1968-07-15


This collection, provided by the principal investigator, consists of hourly averaged solar X-ray fluxes obtained using two different filtering techniques identified as method H and method D. The data are in BCD format originally written on an IBM 7094 computer. 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-h 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 appearing 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 data lists 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.

These data were used by NSSDC to produce the microfilm collection SOXR-00077. Data are available online at

Alternate Names

  • Hourly Avgd Solar X-Ray Flux Data


  • Solar Physics: X-Ray


  • 67-073A-21B

Additional Information



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



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

Selected References

  • Kreplin, R. W., et al., Measurements of solar X-ray emission from the OGO-4 spacecraft, in Sol. Flares and Space Res., 121-130, North-Holland Publ. Co., Amsterdam, The Netherlands, 1969.
  • Wende, C. D., The normalization of solar X-ray data from many experiments, Solar Phys., 22, No. 2, 492-502, doi:10.1007/BF00148712, 1972.
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