Automatic scaling of the sporadic E layer and removal of its multiple reflection and backscatter echoes for vertical incidence ionograms

• An algorithm is presented for automatic scaling of the Es layer.
• We introduce an algorithm for obtaining clean ionograms.
• It can improve the performance of automatic scaling of the F layer.

This paper presents a method for automatically scaling the sporadic E (Es) layer and removing its multiple reflection and backscatter echoes for vertical incidence (VI) ionograms. First, the method scales the Es layer automatically. Then, it removes the traces of multiple reflection and backscatter of the Es layer to clean VI ionograms using the parameters of the Es layer. Ionograms recorded at Wuhan (30.5°N, 114.37°E) are used to verify the performance of the proposed method compared with manually scaled values. The results indicate that the proposed method can automatically scale the Es layer and effectively improve the performance of the technique developed by Jiang et al. (2013).