Ionosonde Description

Ionosonde Instrument Description

Modified IS-14 sounder

Ionosonde:

Modified IS-14 sounder (in operation since 1. Feb. 1977)

Normal vertical sounding program:

Half-hourly, centered at 2 MHz passage.

RWD program:

usually 6 ionograms per hour (several other programs are possible)

Time used in scaled data:

EET (30 deg E, UT + 2 h).

Frequency range:

1 - 16 MHz

Sweep time:

160 seconds

Peak power:

2 kW nominal (actually much less is used)

Pulse repetition rate:

50 Hz

Pulse lenght:

50 microseconds

Echo processing:

Usually the quadrature components of 10 or 20 height sweeps are phase coherently integrated in 1024 channels.

Display:

Ionograms are currently recorded on 35 mm film. Echo is displayed from the maximum of echo to the height where noise level, reference level or minimum in echo pattern is reached. Height markers are at every 20 km. Frequency scale is logarithmic and frequency remarkers at every 1 MHz.

Gain control:

Automatic. Dynamic range of displayed echoes is 20 dB.

Aerials:

Rhombics in 64 m mast.