Inverse Synthetic Aperture Radar Imaging at 580 GHz

We have demonstrated sub-centimeter resolution Inverse Synthetic Aperture Radar (ISAR) imaging using a 580 GHz, frequency modulated continuous wave (FMCW) radar. This ISAR technique uses pulse compression possible with the FMCW waveform to achieve resolution in range, and exploits rotation of the target to achieve resolution in cross-range. The technique relies on the illumination of the entire target rather than scanning with a narrow beam, which permits larger ranges or smaller apertures than real-aperture approaches. The data collection time required for an ISAR image is less than the collection time with a mechanically scanned beam, which is an advantage in highly dynamic scenarios. The ISAR algorithms presented here accommodate radial motion of the target and non-uniform rotation rates. Thus, the algorithms are suitable for applications where the target motion is not under the control of the observer. These algorithms enhance submillimeter-wave radar technology for surveillance and concealed-object detection.