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Ground Based Ionospheric

NSSDCA ID: 1959-009A-06

Mission Name: Explorer 7
Principal Investigator:Dr. George W. Swenson, Jr.


An all-transistor beacon telemetry transmitter was operated at a fundamental frequency of 19.9915 MHz. This transmitter, which was powered by solar cells and rechargeable nickel-cadmium batteries, provided 660 mW of power at the fundamental frequency. It also radiated the second and third harmonics (15 mW each) at 39.9830 and 59.9745 MHz. Beacon receivers were known to have been located in Washington, D.C., and Chicago, Illinois. Interpretation of the changes of beacon signal characteristics between the satellite and the ground station showed irregularities to be present at all times of the day with horizontal dimensions of 5 to 500 km. Data were received over a period of 16 months.

Alternate Names

  • Explorer7/GroundBasedIonospheric


  • Space Physics: Ionospheric Studies

Additional Information

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



NameRoleOriginal AffiliationE-mail
Mr. C. KittleOther InvestigatorNational Bureau of Standards
Dr. George W. Swenson, Jr.Principal InvestigatorUniversity of
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