The ISIS 1 (International Satellites for Ionospheric Studies) Swept-Frequency Sounder measured the
ionospheric electron density in the altitude range 300 to 3500 km, and provided correlative data for the other
ISIS 1 experiments, particularly those measuring ionospheric parameters. The 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 19 or 29 s, and one of six selected frequencies was also used for sounding
for a few seconds during each 19- or 29-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.
Version:2.2.0
The ISIS 1 (International Satellites for Ionospheric Studies) Swept-Frequency Sounder measured the
ionospheric electron density in the altitude range 300 to 3500 km, and provided correlative data for the other
ISIS 1 experiments, particularly those measuring ionospheric parameters. The 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 19 or 29 s, and one of six selected frequencies was also used for sounding
for a few seconds during each 19- or 29-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.
| Role | Person | StartDate | StopDate | Note | |
|---|---|---|---|---|---|
| 1. | PrincipalInvestigator | spase://SMWG/Person/James.H.Whitteker |
Information about the Sweep-Frequency Sounder on ISIS 1