Investigating the superior capabilities of ultra wideband radars to detect small high speed crafts

For conventional narrow-band (NB) radars, a sinusoidal modulated signal with small frequency bandwidth (less than 10 percent of carrier frequency) is used for target detection and ranging. The merits of this type of signal are easy pure sinusoidal wave shape production and frequency selection capabilities. Since, based on Shannon principle, the information rate transmitted in time unit is proportional to signal frequency bandwidth, using narrow-band signal limits the information capability of radio systems. For this reason, to increase signal information, we should extend signal frequency bandwidth or increase the target surveillance (observation) time. When, the target observation time is limited, the second solution is impossible. But, we can use an ultra-wideband (UWB) signal for realizing the first solution. Of course, it is noticeable that UWB signal processing for target tracking is different from NB radars and has more numerical complexity. In this research paper, first, the target detection differences between UWB and NB radars are explained. Then, based on scientific analysis of UWB signal processing techniques, the detection and ranging capabilities and limitations of UWB radars for moving small targets, specially high speed crafts, is analyzed and presented. According to achieved results, it is shown that depending on size and speed of high speed crafts and sea circumstances, UWB radars have limitations which we can use them to stealth our targets from radar detection.