Automatic scaling of critical frequency foF2 from ionograms recorded at São José dos Campos, Brazil: a comparison between Autoscala and UDIDA tools

摘要: This paper considers a dataset of ionograms recorded by the CADI ionosonde installed at Sao Jose dos Campos (SJC; 23.2°S, 45.9°W, magnetic latitude 14.1°S), Brazil, to compare two autoscaling systems: Autoscala, developed Istituto Nazionale di Geofisica e Vulcanologia, and UDIDA-scaling, Universidade do Vale Paraiba. The analysis, focused on critical frequency F2 layer, foF2, shows that systems work differently. UDIDA-scaling gives always value foF2 as output, regardless presence ionogram trace its definition, while Autoscala tends reject for which digital information is considered insufficient. As consequence, can autoscale more values than but discard larger number unidentifiable. Discussions are made accuracy given well main shortcomings characterizing systems.