Embedded synthetic aperture radar imaging system on compact DSP platform

The extensive use of composite materials in the manufacturing of many critical aerospace components makes monitoring the integrity of these composites during their lifecycle a task of paramount importance. Microwave and millimeter wave non-destructive testing techniques have shown practical merits for inspecting thick composite structures compared with other conventional non-destructive testing methods. The utility of microwave near-field imaging with the synthetic aperture radar (SAR) technique offers the ability to focus on the targets at required depths after the data is already acquired. This feature could largely decrease the time needed for the through-thickness inspection processes by focusing at different depths in real-time. Therefore, microwave imaging based on synthetic focusing techniques become of high utility for thick composites inspection. However, the generation of an image using the SAR raw data is a computationally intensive task that is conventionally implemented on elaborate platform, e.g., a computer. Processing the raw data on such platforms hinders the development of handheld real-time imagers which are long sought in the industry. In this paper, synthetic aperture radar algorithm was implemented on a compact DSP board (OMAPL138) and was compared with the implementation using Matlab on a PC. The results showed that DSP produced similar results as the Matlab implementation with a reasonable speed and lower cost. An advantage of having the implementation on the DSP board is the convenience of portability.