spase://ASWS/NumericalData/Ionogram/Vno_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. An IPS 5D ionosonde had been sounding since March 1999 at Vanimo and until it was closed in October 2009. The 5D vertical sounding ionosondes normally sweep in frequency from about 1 to 21.5 MHz. Frequency step resolution for the 5D 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. The raw ionogram file is recorded in a DVD monthly, which will be posted to Sydney SWS head office every month. During 01/01/1995 to 12/05/2000, Vanimo also had an IPS 4D ionosonde. During 20/01/1991 to 22/12/1993, an IPS 5a ionosonde. and During 08/08/1999 to 22/02/2006, a CADI ionosonde. SWS WDC archives all raw ionogram files and cleaned ionogram files. The Vanimo digital clean ionogram data is available since 22/03/1991, and digital raw ionogram data since 01/01/1995. The Vanimo 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 20/07/1964. The Vanimo median data of foF2 and M(3000)F2 are available since 07/1964. The Vanimo station was closed in October 2009.