acoustic navigation造句

• In this paper , the main research works are as follows : 1 ) survey and analysis previous work in auv navigation and summarize : as the cumulate error , the dead - reckoning and inertial navigation systems ca n ' t be used without other modified system ; the acoustic navigation system is used only in small range , and is very expensive . 2 ) two important approaches in geophysical navigation techniques are summarized , one is terrain contour based navigation , this approach is investigated keystone today ; the other is image based navigation , due to no perfect image sensors and image seabed map , this approach has seldom been practised . 3 ) two important terrain contour based navigation algorithms has been applied to auv , one is match algorithm - based terrain contour match ( tercom ) ; the other is kalman filter - based sandia inertia terrain - aided navigation ( sitan )
  主要研究內容包括：一、總結分析了當前水下導航的常用方法和不足之處，指出基于航位推算的導航方法，存在著最大的問題就是導航誤差的積累問題，如果沒有修正系統，這種方法很難滿足使用要求；其次指出基于聲學的導航方法，造價昂貴，導航范圍有限，難以滿足自主水下航行器大范圍導航的需求；二、總結了當前水下地形輔助導航的主要技術路線，一是基于地形高程的匹配方法，這是當前研究的重點；二是基于地形圖像的匹配方法，由于缺乏良好的圖像傳感器，和可用的海底圖像地圖，目前這種方法還有待研究發展；三、將兩種地形高程匹配的常用方法應用到自主水下航行器上：以相關算法為前提的地形輪廓匹配( tercom )方法和以卡爾曼濾波為基礎的桑迪亞慣性地形輔助導航( sitan )方法，前者算法簡單可靠，但是導航精度不高，后者雖然精度比較高，但存在著算法較為復雜、有可能發散和出現奇異值等問題。
• It's difficult to find acoustic navigation in a sentence. 用acoustic navigation造句挺難的