DIDBase: Digital Ionogram DataBase, manually scaled records

Digital Ionogram Database (DIDBase) collection contains vertical-incidence ionogram measurements and ionogram-derived information acquired by Global Ionosphere Radio Observatory (GIRO), https://giro.uml.edu, a network of ionosondes (high-frequency remote sensing sounders). Ionosondes detect echoes of the probing signal of varying frequency that correspond to reflections of the vertically transmitted signal from various locations in the ionosphere illuminated by the signal. Resulting image of the signal strength as function of the operating frequency and the time of flight is called ionogram. When viewed in the ionogram frame, signal echoes form traces that correspond to different plasma layers in the ionosphere. Interpretation of the ionograms allows derivation and computation of actionable numerical information for subsequent use in a variety of applied and research cases.