spase://ASWS/NumericalData/Ionogram/Sal_Ionogram

Ionograms are an image of frequency versus time delay (virtual height) of HF echoes from the ionosphere recorded by an ionosonde. An ionosonde is a swept frequency HF pulsed radar used to monitor the ionosphere. SWS WDC has archived ionogram data from 26 stations, 12 of them are still active at present. The first ananlog ionosonde was installed in Salisbury on 1st of January 1970 and sounded to 30th April 1989. An IPS 5A/5C digital ionosonde had been sounding since 06/08/1991 at Salisburypril until the station was completely closed in December 1992. The vertical sounding ionosondes normally sweep in frequency from about 1 to 21.5 MHz. Frequency step resolution for the is 5kHz, with up to 4095 steps available. The step interval is variable, becoming more coarse at higher frequencies as ionograms are generally displayed on a logarithmic scale. Every five minutes, a Ionogram data file is recorded, cleaned and the cleaned ionogram is transfered to SWS Sydney head office for autoscaling and further analysis. SWS WDC archived all clean ionogram files. The Salisbury digital clean ionogram data is available since 06/08/1991, and digital raw ionogram data is not available. The Salisbury scaled hourly ionospheric data include parameters of foF2, foF1, FoE, foEs, fbEs, fmin, fxl, f'scaling F/s, M(3000)F2, h'F2, h'F, h'E, h'Es, h'Scaling R/S and Type Es. They are avalable since 01/01/1970 to 30/04/1989. The Salisbury median data of foF2 and M(3000)F2 are available since 01/1970 to 12/1989. The Salisbury station was closed in December 1992.