NSSDCA ID: 1971-024A-01
Mission Name: ISIS 2The purpose of this experiment was to measure the ionospheric electron density in the altitude range 300 to 1400 km. Another important function of the sounder was to provide correlative data for the other ISIS 2 experiments, particularly those measuring ionospheric parameters. The ISIS 2 ionosonde was a radio transmitter that recorded the time delay between a transmitted and returned radio-frequency pulse. A continuum of frequencies between 0.1 and 20 MHz was sampled every 14 or 21 s, and one of six selected frequencies was also used for sounding for a few seconds during each 14- or 21-s period. In addition to the sweep- and fixed-frequency modes of operation, a mixed mode was available in which the transmitter frequency was fixed at one of six possible frequencies while the receiver swept. Several virtual-range (delay-time) traces resulting from ground reflections, plasma resonances, birefringence of the ionosphere, nonvertical propagation, etc., were normally observed. Virtual range at a given frequency was primarily a function of distance traversed by the signal, electron density along the propagation path, and mode of propagation. The standard data format was an ionogram (graph) showing virtual range as a function of radio frequency.
Questions and comments about this experiment can be directed to: Dr. Dieter K. Bilitza
Name | Role | Original Affiliation | |
---|---|---|---|
Dr. Yoshiharu Ogata | Other Investigator | Radio Research Laboratory | |
Mr. John E. Jackson | Other Investigator | NASA Goddard Space Flight Center | |
Dr. K. Roland Chan | Other Investigator | NASA Ames Research Center | |
Dr. R. B. Norton | Other Investigator | NOAA Environmental Research Laboratories | |
Dr. Ravipati Raghavarao | Other Investigator | Physical Research Laboratory | raghava@mite.gsfc.nasa.gov |
Mr. J. F. Turner | Other Investigator | Ionospheric Prediction Service | |
Dr. Olav Holt | Other Investigator | Auroral Observatory | |
Dr. Michel Sylvain | Other Investigator | CNRS, Laboratoire de Geophysique Externe | |
Dr. R. S. Unwin | Other Investigator | Department of Scientific and Industrial Research | |
Dr. J. H. Whitteker | Principal Investigator | Department of Communications/Communications Research Centre | |
Mr. Donald B. Muldrew | Principal Investigator | Department of Communications/Communications Research Centre | dmuldrew@rogers.com |