spase://ASWS/Instrument/Ground/Norfolk_Island/Ionosonde

The Norfolk Island Ionosonde station in Norfolk Island, NSW, Australia, has ionosondes since February 1964 to now without shutdown. According to SWS archived scaled ionospheric data book, The first ionosonde was IPS 3D since 02/02/1964. According to the SWS archived Weekly Station Summary, there were IPS 4A (at least in 17/06/1981), IPS 3B (at least in 21/10/1981) and IPS 4B (at least 28/10/1981 to 11/04/1989) in operation in the station. There was an IPS 4D between 16/08/1994 and 24/06/1999, an IPS 5A between 06/07/1993 and 31/12/1993, and a CADI between 04/02/1999 and 09/05/2007. There is an IPS 5D since 16/05/2007 to now. The IPS 5D vertical sounding ionosonde normally sweeps in frequency from about 1.0 to 21.5 MHz. Frequency step resolution for the 5D is 5 kHz, 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.