舰船电子工程
艦船電子工程
함선전자공정
Ship Electronic Engineering
2015年
11期
173-176
,共4页
大气噪声%最佳一致逼近法%逆海洋滤波器
大氣譟聲%最佳一緻逼近法%逆海洋濾波器
대기조성%최가일치핍근법%역해양려파기
atmospheric noise%best uniform approximation method%ocean-compensation filter
针对海水低通特性会使水下超低频段大气噪声波形畸变，使接收超低频信号时信噪比变差的问题，研究了海水在超低频段的幅频特性，仿真了在不同深度上海水对超低频大气噪声的影响，并采用最佳一致逼近法设计了逆海洋滤波器，对畸变的大气噪声波形进行频率补偿。当采样率 fs＝1kHz 时，在30m ～200m 深度上最大采用9阶 IIR 滤波器，可以使逆海洋滤波器的幅频特性与理论值的最大偏差小于0．5dB ，能够很好的还原超低频大气噪声尖峰的锐利程度，提高了接收信号的信噪比。
針對海水低通特性會使水下超低頻段大氣譟聲波形畸變，使接收超低頻信號時信譟比變差的問題，研究瞭海水在超低頻段的幅頻特性，倣真瞭在不同深度上海水對超低頻大氣譟聲的影響，併採用最佳一緻逼近法設計瞭逆海洋濾波器，對畸變的大氣譟聲波形進行頻率補償。噹採樣率 fs＝1kHz 時，在30m ～200m 深度上最大採用9階 IIR 濾波器，可以使逆海洋濾波器的幅頻特性與理論值的最大偏差小于0．5dB ，能夠很好的還原超低頻大氣譟聲尖峰的銳利程度，提高瞭接收信號的信譟比。
침대해수저통특성회사수하초저빈단대기조성파형기변，사접수초저빈신호시신조비변차적문제，연구료해수재초저빈단적폭빈특성，방진료재불동심도상해수대초저빈대기조성적영향，병채용최가일치핍근법설계료역해양려파기，대기변적대기조성파형진행빈솔보상。당채양솔 fs＝1kHz 시，재30m ～200m 심도상최대채용9계 IIR 려파기，가이사역해양려파기적폭빈특성여이론치적최대편차소우0．5dB ，능구흔호적환원초저빈대기조성첨봉적예리정도，제고료접수신호적신조비。
The low‐pass characteristic of the ocean in ELF band will result in distortion of the atmospheric noise and worse signal to noise of the receiver .To address this problem ,magnitude‐frequency characteristic of the ocean in ELF band were researched .Influence on the atmospheric noise in different depth of the ocean was simulated .And ocean‐compensation filter was designed using best uniform approximation method to compensate the distorted atmospheric noise .With the sam‐pling frequency f s = 1kHz ,at 30m ~ 200m depth ,9th‐order IIR filter was used to design ocean‐compensation filter .The maximal error of the magnitude‐frequency characteristic of the filter is less than 0 .5dB compared with the theoretical .With the filter ,the sharpness of the ELF atmospheric noise spikes were restored and the SNR of the receiver was improved .
