In the fifth chapter , we study the speckle filters in context of estimate theory , we find that the problem of the speckle filters is edge preservation . a method name d adaptive multi - look processing is proposed , it reduces speckle while preserving the edges . at last , we evaluate the proposed methods using the simulated sar images , chinese l - band airborne sar images , sir - c / x - sar images and ers - 1 images 第五章首先介绍了斑点滤波的数学物理描述；经过比较分析基于估计理论的斑点滤波方法，研究了这些方法面临的困难；最后提出了名为自适应多视处理的斑点滤波方法，并利用机载l波段sar图像、 sir - c图像和ers - 1图像进行了评估和测试。
This dissertation discuss the key technology of wide band digital t / r module , including : architecture of the wide band digital t / r module ; wide band signal generating technology based on ddws ; using fiber technology to transmit data between radar center and t / r moudle . after studying the digtal t / r module technology over the world , this dissertation present a scheme of l band ( 1300mhz ) wide band ( b = 100mhz ) digital t / r module , and design a test board to verify transmitting technology of wide band digital t / r module , it works at l band . it use gigabit fiber components to transmit data between radar center and t / r module , use ddws and quadrature modulate technology to generate wide band radar transmitting signal , all control signal is generated by fpga 本文探讨了宽带数字t / r组件发射通道的关键技术,主要包括:数字t / r组件的体系结构、基于ddws技术的宽带信号的产生以及数字t / r组件收发数据的光传输技术。本文在深入研究了国内外数字t / r组件技术的基础上,提出了一种l波段( 1300mhz )宽带( b = 100mhz )数字t / r组件的原理框图,并且设计了试验板来验证宽带数字t / r组件发射通道技术。该试验板采用千兆比特光纤技术实现宽带数字t / r组件与雷达主机的数据传输,采用ddws加正交调制技术产生宽带雷达信号,采用一片fpga完成整个组件的控制。
In this paper , a pll frequency synthesizer working in l band is researched . at fist , we review the basic of phase lock loop and it ' s constituent part . after that the basic conception and design method of pll frequency synthesizer was introduced , especially introduced the charge pump pll frequency synthesizer in detail 本文是采用锁相原理设计的l波段频率合成器，首先对锁相环路的工作原理和基本组成部分进行了简单的介绍，然后介绍了锁相频率合成器的原理和设计方法，主要介绍了目前小型频率合成器产品中使用最广泛的由电荷泵数字鉴频鉴相器和无源环路滤波器构成的频率合成器。
The fairly well imaging results indicate that the range - doppler algorithm is effective on the condition of side - looking withoat squillt . after that , we discussed some sources of motion errors and introduced the influence of phase errors to imaging , and came to an conclusion that phase errors is one of the dominating reasons decreasing imaging quality in this dissertation , the experiments of point target imaging were done to explain the problem aroused by quadratic and cubic phase errors influent the imaging . in order to effectively eliminate or reduce the influence of motion ermrs to imaging , thiee representative autofocus a1gorithjns were discussed , i . e . map drift , shift and correlation , phase gradient autofocus 本论文就是以研究运动误差补偿为目的，首先分析了合成孔径雷达的基本原理及其成像原理，应用距离一多普勒（ r d ）成像算法对机载l波段sar实际数据进行了成像，表明r d算法对正侧视的sar数据成像是有效的；然后研究了由运动误差引起的相位误差对成像的影响，得到的结论是：回波数据中的相位误差是导致雷达图象质量下降的主要原因之一；重点针对二阶相位误差的补偿问题，研究了三种具有代表性的自动聚焦算法，用点目标实现了仿真并对实际数据进行了自动聚焦处理，经过自动聚焦前后结果的比较和分析，可以看出：子孔径相关法（ mapnrift ）对二次相位误差估计比较精确、移频相关法侣hiftandcorrelation ）对数据处理速度快、而相位梯度法（ phas 。
