查询词典 SAR

a system of along-track mode sar based on the gps is established.by seeing the gps signal as a chirp,chirp scaling algorithm of this mode with large squint angle is investigated.chirp scaling algorithm is considered more efficient and widely applicable when the bistatic sar system is in side-look or small squint angle mode,but in large squint angle case,the errors caused by taylor expansion are so large that the algorithm could lose its precision.in such a case,an equivalent mono-static sar range mode which has fewer errors than taylor expansion with large squint angle is proposed to substitute the range history of bistatic sar.then bistatic sar images with large squint angles are gotten by common nonlinear cs algorithm.the effectivity of the method is verified by matlab simulation.

摘 要：建立了基于gps的顺轨sar系统模型，通过将gps信号等效为chirp信号，研究了在该模式下的大斜视角chirp scaling算法。在正侧视或小斜视情况下，cs算法具有较好的聚焦性能和广泛的适用性，但在斜视角较大的情况下，该算法将散焦而不能成像，因而提出了用等效的单基地距离模型来代替双基地距离历史的方法，解决了大斜视角情况下距离模型二阶近似误差较大的问题，并结合单基地非线性cs算法，实现了在大斜视角情况下的基于gps反射信号的双基地sar高精度成像，最后通过matlab仿真进行了验证。

The main contents is: analyzing some detection method to moving target nowadays; particular studying the principle of detection moving target in SAR; analyzing SAR imaging theory and the echo model of moving target; discussing conventional SAR imaging , the movements of target cause the changes of doppler mass center and regulable frequency, and the changes cause effect the imaging result; introducing the estimation method of doppler parameter; analyzing theory of DPCA, derivating the formula needed, and validating it's validity and practicability through simulation; advancing the improved DPCA algorithm that combine the advantage of DPCA and ATI, and validating it through computer simulation; using the revision algorithm to range ambulate based on keystone transformation, and validating it through computer simulation; discussing the compensation art of SAR imaging.

主要内容有：分析了现有的一些动目标的检测方法；详细研究了SAR动目标检测的原理；分析了SAR成像理论和运动目标的回波模型；探讨常规SAR成像时，目标运动引起的多普勒质心和调频率变化，以及这些变化对成像结果的影响；介绍了多普勒参数的估计方法；分析了DPCA原理，推导所需要的基本公式，并仿真验证其有效性和实用性；提出了结合DPCA和ATI优点的改进DPCA算法，并仿真验证；探讨了SAR成像中的运动补偿技术。通过对仿真结果的分析，本文提出的方法具有一定的指导意义和参考价值。

C.G, the present main unit of departments of the national search and rescue, is just one of the national SAR units of search and rescue organization. As my experiences of conducting SAR on sea, the duty, the integration , command, coordinate, communicate and cooperation of SAR resources show the efficiency of national SAR system still need to be upgraded.

目前我国的海难搜救能量虽以海巡署的能量为主力，但依目前整体海难救助体系架构观之，其却仅为国家搜救体系下的「搜救单位」之一，以笔者多次执行海上搜救任务观之，我现行海难救护职掌与任务通报流程统合、指挥、协调、联系与救护资源整合共享等，在在显示我国海难救助系统效能仍有大幅成长空间。

Chirp scaling algorithm is considered more efficient and widely applicable when the bistatic SAR system is in side-look or small squint angle mode,but in large squint angle case,the errors caused by Taylor expansion are so large that the algorithm could lose its precision.In such a case,an equivalent mono-static SAR range mode which has fewer errors than Taylor expansion with large squint angle is proposed to substitute the range history of bistatic SAR.Then bistatic SAR images with large squint angles are gotten by common Nonlinear CS algorithm.The effectivity of the method is verified by Matlab simulation.

在正侧视或小斜视情况下，CS算法具有较好的聚焦性能和广泛的适用性，但在斜视角较大的情况下，该算法将散焦而不能成像，因而提出了用等效的单基地距离模型来代替双基地距离历史的方法，解决了大斜视角情况下距离模型二阶近似误差较大的问题，并结合单基地非线性CS算法，实现了在大斜视角情况下的基于GPS反射信号的双基地SAR高精度成像，最后通过Matlab仿真进行了验证。

The 2-D transfer function of the bistatic SAR is obtained. Azimuth position distortion along range existing in the original alogrithm is corrected by mapping from scene coordinate to azimuth-slant distance coordinate. Bistatic SAR date can still be processed by a mono-static SAR processor. The efficaciousness of the proposed algorithm is verified through point target simulations.

算法通过数值计算得到双基地二维传递函数，通过场景坐标系向方位－斜距平面的映射校正了原算法中存在的沿距离变化的方位位置畸变，进而来用常规单基地SAR成像处理流程实现对双基地SAR回波数据的成像处理，最后通过点目标仿真验证了算法的有效性。

L IP SAR members integral coefficient, grade change, business pay all back by it automatically calculate the terminal server, in order to ensure that the IP SAR members personal interests, IP SAR members must indefinite online personal interface checks to verify the status of individual performance and found that access to promptly contact the company for timely correction.

l IP特区会员的积分系数、等级增减、业务薪酬，一律由本网后台终端服务器自动计算，为确保IP特区会员个人利益，IP特区会员需不定在网上个人界面检查、核实个人业绩状况，发现出入及时与公司联系进行及时更正。

Main aspects of the paper include principle of SAR imaging, SAR imaging how to influence location of spaceborne SAR, model of location, principle of InSAR, implement chart of InSAR data processing, key principle and the fulfilling of each links of the procedure.

本文研究的主要内容有：成像的原理、成像算法对位置的影响、定位模型、InSAR的原理、InSAR完整的数据处理流程、流程中关键环节的理论和具体实现方法。

In order to correct these geometric distortions on satellite SAR image, and cooperate this information on SAR image with the information from other sensors, it is necessary to geocode original SAR image, and obtain correct standard geocoded image in the defined map projection.

为了校正星载SAR图象的几何畸变，使SAR图象上的数据信息和其它传感器上得到的信息进行融合，必须对星载SAR原始图象进行地理编码，得到校正后的统一的地图坐标系上的标准地理编码图象。

In modern specification of handset, there is one about SAR. However, current mobile phone antenna is dipole antenna with omni-directional radiation pattern in azimuth plane. So much better performance of antenna means higher SAR value. Therefore, in order to improve SAR performance, designer may be forced to detune antenna or use resistor. The two methods will reduce efficiency of antenna.

在移动电话的技术规范中往往有SAR值的要求，这给手机天线的设计带来了严峻的挑战，因为现代的手机天线基本上是在水平面具有全向辐射特点的偶极子天线，因此天线的性能越好往往SAR值越高，所以有时为了降低SAR值甚至故意劣化天线的性能。

Based on the analysis of bistatic SAR geometry model, bistatic SAR echoed signal is modeled in the double range variables domain in this paper, and the relationship between the double range variable domain and the single range variable domain is established. Then a range-dependent Doppler algorithm for imaging processing airborne bistatic SAR raw data of the translationally invariant configuration is derived, and the effect of error of the algorithm is analyzed by simulating.

摘要该文通过对机载双基地SAR非移变几何模型的分析，建立了双距离变量域的回波信号模型，由于回波数据是在距离和域，该文推导了距离和变量与双距离变量的转换关系，解决了该模型向距离和变量域转换的问题；提出了适用于非移变模式的变多普勒参数的双基地RD算法，并对该算法中引入变多普勒斜率所存在的误差进行了仿真分析。

Foods high in this vitamin include oily fish such as salmon, tuna and, and fish liver oils.

维生素D含量高的食物包括诸如大麻哈鱼、金枪鱼和鲭鱼之类的油鱼以及鱼肝油。

We need you to cosign our public letter demanding that press intimidation cease immediately, and that all charges be dropped.

我们需要您cosign我们的公共信，要求记者立即停止恐吓，并要求所有收费下降。