FMCW radar signal processing - Application on INDERA

At present, radar has become a standard system on all commercial vessels, and is widely used in the leisure maritime sector. Especially in the area with high dense vessel traffic, radar retains its primary role in collision avoidance. The use of radar as primary navigational aid as well as safety tool is still an essential part of safe watch-keeping. There are two types of radars: pulse and continuous wave radar. In a frequency modulated continuous wave (FMCW) radar system, the radar device continuously transmits electromagnetic signals whose frequencies are modulated to detect targets in the surrounding area. Compared to more common conventional pulse radar, FMCW radar uses low power to transmit its signals. By applying the Fourier transform, radar echoes coming from targets at a particular direction are projected onto a radial path on the display screen. When the radar antenna performed one full cycle rotation and received all radar echoes from every direction, we will obtain a complete two dimensional radar image. A skilled radar operator can visually recognize certain targets (e.g. suspicious moving targets) among other objects within the radar image. However, this visual method will work only in good weather conditions in which the effects of clutters are negligible small. In other situations, where the clutter effects cannot be neglected anymore, it is very difficult –if it is not impossible– for human eyes to detect and recognize real targets from the noisy radar image. In fact, very similar situations are often encountered when the FMCW radar is operated as marine radar during a sea voyage. In such a situation, only an experienced radar operator can perform the recognition task without great difficulties. Thus, in either situation, automatic target recognition is very useful for the operation of an FMCW radar. This feature can significantly improve the performance of an FMCW radar and hence increase the safety of a sea voyage.