Articles | Volume 5, issue 1
Geosci. Instrum. Method. Data Syst., 5, 53–64, 2016

Special issue: Multi-disciplinary research and integrated monitoring at the...

Geosci. Instrum. Method. Data Syst., 5, 53–64, 2016

Research article 23 Mar 2016

Research article | 23 Mar 2016

Comparison between manual scaling and Autoscala automatic scaling applied to Sodankylä Geophysical Observatory ionograms

Carl-Fredrik Enell1, Alexander Kozlovsky2, Tauno Turunen2,*, Thomas Ulich2, Sirkku Välitalo2, Carlo Scotto3, and Michael Pezzopane3 Carl-Fredrik Enell et al.
  • 1EISCAT Scientific Association, Kiruna, Sweden
  • 2Sodankylä Geophysical Observatory, University of Oulu, Sodankylä, Finland
  • 3Istituto Nazionale di Geofisica e Vulcanologia (INGV), Rome, Italy
  • *retired

Abstract. This paper presents a comparison between standard ionospheric parameters manually and automatically scaled from ionograms recorded at the high-latitude Sodankylä Geophysical Observatory (SGO, ionosonde SO166, 64.1° geomagnetic latitude), located in the vicinity of the auroral oval. The study is based on 2610 ionograms recorded during the period June–December 2013. The automatic scaling was made by means of the Autoscala software. A few typical examples are shown to outline the method, and statistics are presented regarding the differences between manually and automatically scaled values of F2, F1, E and sporadic E (Es) layer parameters.

We draw the conclusions that:

1. The F2 parameters scaled by Autoscala, foF2 and M(3000)F2, are reliable.

2. F1 is identified by Autoscala in significantly fewer cases (about 50  %) than in the manual routine, but if identified the values of foF1 are reliable.

3. Autoscala frequently (30  % of the cases) detects an E layer when the manual scaling process does not. When identified by both methods, the Autoscala E-layer parameters are close to those manually scaled, foE agreeing to within 0.4  MHz.

4. Es and parameters of Es identified by Autoscala are in many cases different from those of the manual scaling. Scaling of Es at auroral latitudes is often a difficult task.

Short summary
Ionograms from the Sodankylä Geophysical Observatory ionosonde (station SO166) were scaled automatically with the Autoscala software during a test period. The results were compared with manually scaled ionospheric parameters. In general, the F-layer parameters were found to agree well, whereas high-latitude phenomena like auroral E layers were often misidentified.