Long-term Schumann resonance dynamics based on horizontal magnetic field data at Mikhnevo observatory during 2016–2020

It is the first time when we present a significant amount of two-channel (north-south and west-east) absolute magnetic field data in the extremely low frequency (ELF) band for the European Russia. The measurements are evaluated at Mikhnevo geophysical observatory of the Sadovsky Institute of Geosphere Dynamics. We start with a recently proposed unified processing procedure by Rodriguez-Camacho et al. (2018, https://doi.org/10.1029/2018jd029462) and further elaborate an ELF spectrum calculation technique. The true sequence of the spectrum calculation is presented, including the proper parameters, software requirements, and the use of third-party libraries. We receive an optimal set of processing parameters for Mikhnevo observatory and discuss the long-term (2016–2020) Schumann Resonance variations.