The propagation characteristics of underwater acoustic channels and their influences on long - range information transmission are studied thoroughly . based on the sonar equation , the optimal frequency band is abtained . from the calculation about transmission loss , the source level is forecasted . based on the random time varying channel theory , the fading characteristics of long - range underwater acoustic channels are analyzed 系統(tǒng)、深入地研究了水聲信道特性及其對水聲遠(yuǎn)程信息傳輸系統(tǒng)的影響;從聲納方程出發(fā),確定了系統(tǒng)的最佳工作頻段;在聲傳播損失計算的基礎(chǔ)上,給出了聲源級的預(yù)報;基于時變信道理論,描述了遠(yuǎn)程水聲信道的衰落特性。