Ultrasonic control of the level of the heterogeneous surface medium in mining Volodymyr Morkun, Svitlana Hryshchenko, Oleksandra Serdiuk and Аndrii Ilnitskyi E3S Web Conf., 123 (2019) 01013 Published online: 22 October 2019 DOI: 10.1051/e3sconf/201912301013