摘要 |
<p>In a radio-frequency radar system, a radar antenna (12) irradiates a region to be monitored, and antenna elements (14a-p) arrayed irregularly about a mobile platform (10) receive the resultant echo signal, which mixers (18 and 21) translate in frequency, coherently with the transmitted signal, to a lower frequency, at which a sample-and-hold circuit (24) can sample it. A beam-forming operation is performed on the sample signals by employing coefficients that have been computed from calibration readings taken by the elements mounted on the platform. The beam signals resulting from numerous successive transmitted pulses are then integrated coherently to produce an output.</p> |