The free ions and electrons of ionosphere make it an important region for the propagation of radio waves. Ionospheric measurements, cosmic magnetism, electron density, study of mesosphere, data analysis, etc. are some of the significant topics discussed in this book. It is an essential guide for both academicians and students who wish to pursue the study of ionosphere further. Coherent flow of topics, and extensive use of examples make this book an invaluable source of knowledge.