length n. 1.长,长度,长短。 2.(时间的)长短,期间。 3.(赛艇的)一艇的长度;一马的长度。 4.程度,范围。 5.【板球】球程;投至适当距离的球。 6.【语言学】音长。 7.一段,一节。 a dress length, a length of cloth 一段料。 a length of pipe [tubing] 一节管子。 The boat won by three lengths. 这只艇以三艇长之差得胜。 a (good) length ball 球程准确的球。 at arm's length 在手臂伸得到的地方,疏远 (keep sb. at arm's length 不与接近,敬而远之)。 at full length 1. 冗长地;充分地,详细地 (give all the facts at full length 提供详细的材料)。 2. 全身平伸地 (lie at full length 挺直身体躺着)。 at great length 冗长地,??唆唆地。 at length 1. 最后,终于,好容易才。 2. 充分地,详细地 (speak at great length 详细讲了好久)。 at some length 相当详尽地。 cannot see beyond the length of one's nose 鼠目寸光。 draw out to a great length 拖得很久,占去很长时间。 fall [measure] all one's length 直挺挺地倒下。 find [get, have, know] the length of sb.'s foot 了解某人的弱点。 go (to) all lengths [any length] = go to great lengths 什么事都做得出;不遗余力。 go (to) the length of (doing) 甚至于,不惜。 go the whole length of it. 彻底干;干到底。 length of (sb.'s) days [life] 某人的寿命。 measure one's (own) length 跌倒在地。 of some length 相当长。 over [through] the length and breadth of 到处,四面八方。 work at arm's length 在不利的条件下工作。
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 本论文做了以下研究工作:首先,实现了运用greco方法计算了高频区理想导体复杂目标的雷达散射截面( rcs ) ,分别应用了物理光学法( po )和增量长度绕射系数法( ildc )计算了目标的面元和棱边的电磁散射,最后综合面元与棱边的散射效应得到目标的总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 对于镜面反射采用物理光学法计算其散射贡献,结合基于面元的目标模型的表示,采用离散的积分形式,将面电流积分化简为线积分,简化计算复杂度;对于边缘绕射,运用增量长度绕射系数理论计算目标边缘绕射场;在多次反射中,则以光线跟踪方法为基础,采用几何光学、物理光学相结合的方法分析考虑多次散射场。