The virtual height of the ionograms, manually and automatically scaled parameters will be calibrated from June 19, 2025.
【Target Station and Period】
・Wakkanai/Sarobetsu（WK546）：Observation after May 13, 2016
・Kokubunji（TO536）：Observation after May 15, 2017
・Yamagawa（YG431）：Observation after January 1, 2017
・Okinawa/Oogimi（OK426）：Observation after Nobember 27, 2017
【Calibration Details】
・Virtual height of ionograms will become 24km heigher than the original one.
・Manually and automatically scaled h'Es, h'E, h'F, h'F2 will increase by several to 20km, depending on parameters.
【Notice】
・Please be aware that some data display problems may occur due to the migration process.
・We will notify you on this website as soon as the work is completed.
・We have started 5-minute inverval operation on June 1, 2020.
・There may be irregular delays in updating data due to system maintenance or equipment failure.
・The service may be suspended when access is concentrated.