New methods for radar signal understanding

We discuss the significance of the efforts towards understanding radar signals. Different parts of this endeavour have been termed using different phrases such as signal classification, scene classification, target recognition, parameter extraction. However, we can identify the common thread. All these efforts have one thing in common. They all help radar engineers interpreting the shadows in Plato's Allegory of the Cave! The research in the domain of radar signal understanding has seen some interesting new developments. This has been mainly due to the developments around cognitive radar and the use of modern machine learning algorithms. It was the editors' belief that an edited book to consolidate such efforts will be extremely beneficial. Maybe it is time to put all these pieces of research under one umbrella of 'radar signal understanding' to give a coherent and holistic picture. It was exciting to note that the IET appreciated this vision and many of our well-known colleagues consented to contribute chapters to this humble endeavour.