length n. 1.長,長度,長短。 2.(時間的)長短,期間。 3.(賽艇的)一艇的長度;一馬的長度。 4.程度,范圍。 5.【板球】球程;投至適當距離的球。 6.【語言學】音長。 7.一段,一節(jié)。 a dress length, a length of cloth 一段料。 a length of pipe [tubing] 一節(jié)管子。 The boat won by three lengths. 這只艇以三艇長之差得勝。 a (good) length ball 球程準確的球。 at arm's length 在手臂伸得到的地方,疏遠 (keep sb. at arm's length 不與接近,敬而遠之)。 at full length 1. 冗長地;充分地,詳細地 (give all the facts at full length 提供詳細的材料)。 2. 全身平伸地 (lie at full length 挺直身體躺著)。 at great length 冗長地,??唆唆地。 at length 1. 最后,終于,好容易才。 2. 充分地,詳細地 (speak at great length 詳細講了好久)。 at some length 相當詳盡地。 cannot see beyond the length of one's nose 鼠目寸光。 draw out to a great length 拖得很久,占去很長時間。 fall [measure] all one's length 直挺挺地倒下。 find [get, have, know] the length of sb.'s foot 了解某人的弱點。 go (to) all lengths [any length] = go to great lengths 什么事都做得出;不遺余力。 go (to) the length of (doing) 甚至于,不惜。 go the whole length of it. 徹底干;干到底。 length of (sb.'s) days [life] 某人的壽命。 measure one's (own) length 跌倒在地。 of some length 相當長。 over [through] the length and breadth of 到處,四面八方。 work at arm's length 在不利的條件下工作。
At present greco is regarded as one of the most valuable methods of radar cross section ( rcs ) computation in the high - frequency region . depending on these conditions , several researches have been completed in this paper : firstly , calculating rcs of complex conducting targets has been accomplished by greco method . the high - frequency rcs of targets are obtained through physical optics ( po ) and incremental length diffraction coefficients ( ildc ) respectively 本論文做了以下研究工作:首先,實現(xiàn)了運用greco方法計算了高頻區(qū)理想導體復雜目標的雷達散射截面( rcs ) ,分別應用了物理光學法( po )和增量長度繞射系數(shù)法( ildc )計算了目標的面元和棱邊的電磁散射,最后綜合面元與棱邊的散射效應得到目標的總rcs 。
Incremental length diffraction coefficients ( ildc ) is adopted to calculate the contribution of edge diffraction . in order to improve the accuracy of calculation , multi - scattering is discussed , based on the two former contributions and ray - tracing method . geometrical optics ( go ) and physical optics ( po ) are used to calculate the multi - reflection between facets and facets 對于鏡面反射采用物理光學法計算其散射貢獻,結合基于面元的目標模型的表示,采用離散的積分形式,將面電流積分化簡為線積分,簡化計算復雜度;對于邊緣繞射,運用增量長度繞射系數(shù)理論計算目標邊緣繞射場;在多次反射中,則以光線跟蹤方法為基礎,采用幾何光學、物理光學相結合的方法分析考慮多次散射場。