Research activity on microwave imaging has evolved rapidly, and it is almost impossible to mention the plethora of new ideas, methods, and strategies that continuously appear in the scientific literature and are proposed by a number of very active research teams working around the world and discussed at many conferences devoted to applied electromagnetics. Nevertheless, some more recent ideas concerning possible new imaging strategies and emerging solutions can be summarized, in an attempt to delineate the trend in scientific research in this field.
One trend is certainly represented by the development of hybrid techniques, which allow utilization of the specific features of the different methods applied in combination. This topic has been discussed in Chapter 8. It should be mentioned once again that the ability to devise specific techniques for any particular application is of paramount importance from an engineering perspective, since it is absolutely evident that general-purpose approaches cannot be developed.
However, besides hybrid techniques, other strategies, approaches, and particular applications have been proposed by the research community. Some of them are discussed in the following sections, without any claim of completeness.
Most of the approaches described in the previous sections concern ...