The muon charge ratio of the lateral muon density distributions in single EAS
is studied by simulations, in context of recent proposals to measure this
observable in coincidence with EAS observations. While effects of the hadronic
interaction do not lead to significant differences of the total muon plus and
muon minus content, the differences of the azimuthal variation of the muon
densities of opposite charges and the azimuthal variation of the muon charge
ratio appear to be very much pronounced, dependent on the direction of EAS
incidence. This is due to the influence of the geomagnetic field which induces
related effects in radio emission from extended air showers.Comment: accepted for publication in Journal of Physics