Based on these studies , the properties of doppler and resolutions are analyzed . because the imaging algorithm of bistatic sar is related to the geometry models , the dissertation gives particularly empathies on the parallel model and the static receiver model in the broadside side - looking and stripmap 本文首先建立了任意飞行模式下双基地sar的几何模型和回波模型,分析了其多普勒特性和分辨率特性,得出双基地sar成像算法与飞行模式有密切关系的结论。
About three in the afternoon he came up with us , and bringing to by mistake , just athwart our quarter , instead of athwart our stern , as he intended , we brought 8 of our guns to bear on that side , and pour d in a broadside upon him , which made him sheer off again , after returning our fire , and pouring in also his small shot from near 200 men which he had on board 他们本想攻击我们的船尾，结果却横冲到我们的后舷。我们把八门炮搬到了这一边，一起向他们开火。海盗船边后退，边还击他们船上二百来人一起用枪向我们射击。
3 . after the parameters of the array structure are got , simulation software , such as cst microwave studio , cts design studio and ansoft hfss , are used to design the power dividers for the radiation units in the horizontally polarized direction of the array . these power dividers adopt structure of coupling slots in the narrow side of main rectangular waveguides , in which the narrow side of the main waveguide and the broadside of secondary waveguides are crossed at locations of each slot 3 .在得到满足指标要求的阵列结构参数后,采用cstmicrowavestudio 、 ctsdesignstudio和ansofthfss等电磁仿真软件对阵列在水平极化方向的行馈功分器进行仿真设计,该阵列的行馈功分器采用波导窄边单缝耦合馈电结构。
The performance of the pbg antenna using the new pbg cover together with a pbg substrate is studied by the fdtd method together with the pml boundary treatment . the numerical results show that a more focused beam radiated in the broadside direction is achieved . the gain of the pbg patch antenna in the forward direction is improved by about 6 db . the radiation directivity is improved significantly and reaches 11 . 5 db , which is 0 . 4 db less than the maximum value that is allowed physically for this size of the antenna ( this difference is about 4 . 1 db less than the difference achieved by thevenot et al . , 用fdtd方法并结合pml吸收边界条件，我们对加了这种新的覆层结构并且基底钻孔的复合结构电磁(光子)晶体贴片天线的性能进行了研究，结果证明加了这种新的电磁晶体覆层结构以后，天线的波束收拢很多，并且向前辐射的增益大大提高，与普通天线相比，天线的e面和h面方向图上向前辐射的增益均提高了约6db ，另外，该复合结构天线的方向性系数达到了11 . 5浙江大学博士学位论文db ，与该物理尺寸天线的方向性系数的理论极限值( 11 . 9db )相差0 . 4db ，该差值比thevenot等人设计的电磁晶体覆层天线的相应差值减少了约4 . 1db ，比qiu等人设计的电磁晶体天线的相应差值减少了约1
A chirp scaling algorithm for airborne bistatic sar is proposed , which is suitable for the flight configuration that transmitter and receiver follow parallel path with equal velocity in broadside looking mode . airborne bistatic sar echoed signal model of this particular flightpaths is derived . the model is converted into the range doppler space and is mapped from double range variables to single range variable domain 本文建立了这种特殊飞行模式下双基地sar的回波信号模型,推导了它在距离多普勒域的表达式,解决了信号模型从双距离变量域向单距离变量域转化的问题,并推导了cs因子的线性近似表达式,分析了算法中各种近似造成的误差。
