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Index of Ionograms Showing Ducted Echoes


Availability: Archived at NSSDC, accessible from elsewhere

Time span: 1965-11-29 to 1971-10-30


This data set, prepared at the Communications Research Centre in Ottawa, Canada, is an index to low-latitude ionograms containing ducted echoes. The data are on an EBCDIC magnetic tape written on an IBM 360 computer. The criterion for selection was that at least one trace from the conjugate hemisphere appeared on the ionogram. Each record contains the satellite identification, ground station (Quito=5, Santiago=8, Ft. Meyer=3, Orroral=21, Singapore=48), pass start time (UT), the number of ionograms in the pass showing ducted echoes, and the number not showing ducted echoes. For 4452 Alouette 2 passes (about 1.1E5 ionograms), approximately 2000 ionograms with ducted echoes were identified. Similar data for other times are stored on the same tape and are described under data sets 62-049A-01Q, 69-009A-01E, and 71-024A-01E.

Data are available online at

Alternate Names

  • CRC Index of Ducted Echoes
  • Conjugate Echo Data From Topside Sounder Ionograms


  • Space Physics: Ionospheric Studies


  • 62-049A-01Q
  • 65-098A-01N
  • 69-009A-01E
  • 71-024A-01E

Additional Information



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



NameRoleOriginal AffiliationE-mail
Dr. R. P. SharmaData ProviderDepartment of Communications/Communications Research Centre
Dr. R. P. SharmaGeneral ContactDepartment of Communications/Communications Research Centre
Mr. Robert M. CandeyGeneral ContactNASA Goddard Space Flight
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