【摘要】 为进行弱信号检测,研究在脉冲雷达中获得大信号时间宽度与信号带宽积的方法,利用伪随机编码方法调制超宽带短脉冲,可以在保持子脉冲信号带宽的情况下,以低功率发射长脉冲串类噪声信号,而提高信号的能量,提高探测距离。通过仿真实验得出,利用伪随机编码技术可以使超宽带信号具有更强的探测能力,可以在回波信号功率水平远远小于噪声水平(如信噪比5%)的情况下实现对探测目标的高保真成像。更多还原

【Abstract】 Research method to achieve large bandwidth pulses for detecting neural weak signal is given.Much larger survey depth,better resolution ratio,more powerful image capability and recognition capability can be achieved by using UWB electromagnetic pulse as survey signal than using harmonic wave.However,transmit power of search-and-rescue radar,whose transmit signal is UWB electromagnetic pulse,is much restricted.In this paper,it is discussed in detail that pseudo-random code can be used to modulate UWB short pulse.Encoded signal can keep the bandwidth of the sub pulse signal and have high energy.So that the search-and-rescue radar can transmit noise-like long seriary pulses signal at a low power and improve the survey distance.Based on the fundamental research and computer simulation,that it is concluded UWB short pulse signal has enhanced detection ability and high fidelity image can be obtained under the situation when the echo signal power level is much lower than the noise level(signal-to-noise is 5%) by using the pseudo-random code technique.更多还原