M. Heumesser, O. Chanrion, T. Neubert, K. Dimitriadou, C. Kohn, F. J. Gordillo-Vazquez, A. Luque, F. J. Perez-Invernon, H. Christian, R. Blakeslee, N. Østgaard, A. Mezentsev and M. Marisaldi, Inferring Source Altitudes for Optical Emissions Associated with TGFs, EGU General Assembly, Vienna, Austria, 4-9 May, 2020