The Istituto Nazionale di Geosifica e Vulcanologia (INGV) software for automatic scaling of ionograms (Autoscala) was improved by introducing a system to identify D region absorption events, spread-F condition (frequency spreading in the F region), and Z-ray propagation. The algorithm was applied to a series of ionograms recorded by the AIS-INGV (Advanced Ionospheric Sounder-INGV) ionosonde installed at the Mario Zucchelli Station (74.7°S, 164.1°E), Terra Nova Bay, Antarctica. Critical cases are shown to illustrate the behaviour of the software.
