Millimeter-Wave Radar Targets and Clutter [Book Review]

Millimeter waves are generally defined as radio frequencies between 30 and 300 GHz. Initial serious trials to use them were apparently made during the Second World War. For example, German radar experiments were carried out up to 150 GHz in 1945, but with no practical success. The interest in applying very short wavelengths is partly based on the possibility of getting extremely wide modulation bandwidths whereby we could expect a tremendous increase in communications capacity. Putting 150 Mbit/s uncoded on a UHF carrier would consume the entire part of that spectrum region, but at 90 GHz, there might be some space left. Radar people have been fascinated by the size reduction of antennas feasible if higher frequencies are used. Clutter reduction to a certain extent and enhanced spatial resolution look possible. Millimeter waves have suffered from the lack of compact, easy-to-use high power amplifiers and the availability of cost-effective really low-noise front-ends has not been good either. Besides these technology issues, the fundamental characteristics of the propagation medium close to Earth at millimeter waves does not encourage long-distance hops except for a couple of limited “windows;“ for example, at 94 GHz. Anyhow, the benefits have been considered adequate, and hard work is still ongoing. The book now under review, MillimeterWave Radar Targets and CJufter by Professor Gennadiy Kulemin is a compilation of recent activities and knowledge within this particular field. Let’s first have a look at the StruCNre of this book. It is divided into seven main chapters and contains an alphabetical index of about 900 items from which to search. Chapter 1 gives an introduction to the world of fundamental radar concepts, such as radar cross section, target characteristics and statistics, and elementary detection issues. In addition, there’s an interesting sub-chapter about radar reflections from explosions and gas wakes of operating engines. Here, the author also gives guidelines about the influence of a nearby surface on the statistical properties of target echoes. Chapter 2 is about land backscattering and includes a theoretical introduction and many experimental results. This approach is further extended in Chapter 3, where we have a rather detailed treatment of land parameter estimation through the use of multichannel radar signals. Sea backscattering at low grazing angles is the topic for Chapter 4. As usual, in these contexts, a lot of effort and lines are devoted to the definitions and explanations of different forms of surfac,: perturbations during windy conditions. Chapter 5 concentrates on volume clutter coming from precipitation and other meteorological phenomena. Two special sections highlight experimental results and reflections from clear-sky radar angels. Simulation and modeling issues of surface clutter are treated in Chapter 6. Due to known differences, this discussion is split into land and sea environments. Finally, Chapter 7 gives basic guidelines for the reduction of clutter effects in millimeter-wave radar systems. The author has also included some interesting multipath examples within this part of lhis work. The author, Professor Gennadiy Kulemin, got his master’s degree in radio engineering in 1960 from the Kharkov Polytechnic Institute and received his Ph.D. ten years later. His academic achievements also include a Doctor of Science degree in electronic systems from 1987. Professor Kulemin has been an assistant profwsor and senior lecturer on the Electronic Systems Faculty of the Kharkov Aviation Institute. Since 1966, he has worked at. the Institute of Radiophysics and Electronics of the Ukrainian National Academy of Science. Currently, he is a principal scientist in the Millimeter Radar Department and a Professor at Kharkov Military University. It is well worth mentioning that Professor Yakov Shirman, the author of Computer S,imulntion of Aerial Target Backscattering, Recognition, Detection and Tracking (Artech House 2002, reviewed in Systems Magazine, No. 11, 2002) works in Kharkov. Professor Kulemin’s main research interests include radio signal backscattering from targets and their environment, radar remote sensing, and millimeter-wave radar systems. As becomes evident when reading Kulemin’s text, he has been deeply involved both in the theoretical and practical aspects of these research fields. Before this book, Professor Kulemin had already authored in Russian about similar topics and has written more than 200 scientific publications. In addition to his Ukrainian and former Soviet-era appointments, Professor Kulemin is also a member of URSI and IEEE. The book’s style is a nice balance between theory and experiments. This is also indicated by the numbers: there are