This collection of works by the distinguished Russian scientist V. A. Kotelnikov (1908-2005) has been prepared to commemorate the 100th anniversary of his birth. The third volume features his groundbreaking research on radar mapping of the surface of Venus. The radar imaging of the planet, conducted between 1983 and 1984 under Kotelnikov's leadership, utilized the onboard integrated radar system of the automatic interplanetary stations "Venus-15" and "Venus-16." This endeavor marked a significant milestone in planetary radar research. The ability to obtain global images of a planet shrouded in clouds represented an extraordinary scientific achievement, contributing immensely to global science. The analysis of these images has significantly advanced our understanding in the field of comparative planetology. This book is essential reading for scientists, specialists, students, and anyone interested in the history and achievements of domestic science in space exploration and radio astronomy.