<p>About this dataset: This dataset contains ionograms in PNG format and covers data from September 01-30, 1990.</p><p>About the Tromsø Ionosonde (1984-1992): During the period 1984-
The Ny-Ålesund radiosonde program is part of the GCOS Reference Upper-Air Network (GRUAN). Please consider using the Ny-Alesund reference radiosonde data with higher temporal resolution and uncertaint
