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INMARSAT──P全球数字手持卫星电话系统中国交通通信中心王雪敏一、简介先进的数字化手持卫星电话系统(IN-MARSAT—P),是国际海事卫星组织(IN-MARSAT)迅速发展的多种移动卫星通信系统之一。INMARSAT移动卫星通信,继A系统之后... 相似文献
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INMARSATC系统及其广泛应用王雪敏一、前言INMRSATC系统是国际海事卫星组织(INMARSAT)在1990年开通运行的一种全球移动卫星通信系统,也是INMARSAT继A系统之后开发出的又一种新系统。该系统为全数字化的通信系统,采用了存贮转发... 相似文献
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本文主要介绍国际海事卫星组织及INMARSAT全球移动通信系统,揭示INMARSAT航空系统的基本构成,航空陆上地球站和航空地球站的功能及主要技术指标,重点是整个系统的运行过程进行分析。 相似文献
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本文介绍了INMARSAT系统目前推出的新型通信终端,叙述了这些通信终端所采用的现代通信新技术,着重阐述了INMARSAT-B/M两种终端的通信技术、特点及其在全球个人通信中的作用。 相似文献
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主要介绍了INMARSAT-C系统的E-mail业务,给出了利用Internet和INMARSAT-C系统在船站和陆地用户之间发送 E-mail的方法。 相似文献
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主要探讨了INMARSAT卫星通信系统在航空领域的应用及其展望,同时介绍了INMARSAT航空卫星通信系统的组成和与其他系统的差异,以及航空卫星通信系统在世界范围内的用户情况。 相似文献
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本文概述INMARSAT21世纪工程的规划及为实现这一规划,INMARSAT组织在本世纪末正在进行和即将进行的一系列卫星通信技术工作。着重阐述INMARSAT21世纪工程的业务性能以及对三种卫星布局方案进行拟抉择的新动向。 相似文献
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新一代海事卫星通信系统-INMARSAT-B/M系统中国交通通信中心王利回顾80年代初期,INMARSAT开发实现了全球A标准通信系统。到目前为止,A系统已成功地运行了10余年时间,为广大海上及陆地用户提供了有效的卫星通信手段。80年代末期,INMA... 相似文献
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An asymptotic expansion of the theoretical model for simulation of a monochromatic ocean wave imaging by either regular synthetic aperture radar (SAR), or by along-track interferometric SAR (INSAR), and its analytical approximation are considered. The model takes into account the so-called velocity bunching imaging mechanism. The domains of validity of the simplified asymptotic and analytical expressions for both SAR and INSAR imaging of the ocean waves are established by comparing those solutions with the corresponding full numerical simulations. The analytical presentations of the SAR and the INSAR wave imaging obtained in the present study are used to understand better the limitations and the relative advantages of both techniques and to define the dimensionless parameters which govern the imaging process 相似文献
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The authors have utilized a set of Seasat synthetic aperture radar (SAR) data that were obtained in nearly repeat ground-track orbits to demonstrate the performance of spaceborne interferometric SAR (INSAR) systems. An assessment of the topography measurement capability is presented. A phase measurement error model is described and compared with the data obtained at various baseline separations and signal-to-noise ratios. Finally, the implications of these results on future spaceborne INSAR design are discussed 相似文献
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《Geoscience and Remote Sensing, IEEE Transactions on》1997,35(1):25-35
Properties of ERS-1 C-band repeat pass interferometric SAR information for a forested area are studied. The intensity information is rather limited but, including coherence and effective interferometric SAR (INSAR) height, more information about the forest parameters can be obtained via satellite. Such information is also important for correction of INSAR derived topographic maps. Coherence properties have been used to identify forested/nonforested areas and the interferometric effective height of the forest determined by comparison to a DEM of the area. The authors have developed a model to relate basic forest properties to INSAR observations. These show that the coherence and interferometric effective height of a forested area change between image pairs. The model demonstrates how these properties are related to the temporal decorrelation and the scattering from the vegetation canopy and the ground surface. Gaps in the vegetation are found to be important in the characterization of boreal forests 相似文献
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该文基于主辅星编队模式下的分布式卫星SAR系统,对Range-Doppler域地面运动目标检测方法进行了改进,提出回波信号经方位向相位补偿后,应用Chirp-Z变换能够将地面同一方位单元回波的频谱在不同通道内精确配准,而后通过干涉处理和频谱相位补偿来提取运动目标信息,并给出了频谱相位补偿对系统参数的约束条件以及频谱配准对目标速度的约束条件。最后仿真表明该方法在约束条件下是有效的。 相似文献
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An algorithm for interferometric SAR data processing 总被引:1,自引:0,他引:1
In this paper, an algorithm of generating INSAR unwrapped phase image from SAR single-look complex images is presented. Besides the general processing technique, this article focuses on the methods of flat-earth phase removal, phase noise reduction and phase unwrapping. The availability is tested by the results of processing ERS-1/2 SAR images. 相似文献
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A coherent scattering model for tree canopies is employed in order to characterize the sensitivity of an interferometric SAR (INSAR) response to the physical parameters of forest stands. The concept of an equivalent scatterer for a collection of scatterers within a pixel, representing the vegetation particles of tree structures, is used for identifying the scattering phase center of the pixel whose height is measured by an INSAR. Combining the recently developed coherent scattering model for tree canopies and the INSAR Δk-radar-equivalence algorithm, accurate statistics of the scattering phase-center location of forest stands are obtained numerically for the first time. The scattering model is based on a Monte Carlo simulation of scattering from fractal-generated tree structures, and therefore is capable of preserving the absolute phase of the backscatter. The model can also account for coherent effects due to the relative position of individual scatterers and the inhomogeneous extinction experienced by a coherent wave propagating through the random collection of vegetation particles. The location of the scattering phase center and the correlation coefficient are computed using the Δk-radar equivalence simply by simulating the backscatter response at two slightly different frequencies. The model is successfully validated using the measured data acquired by JPL TOPSAR over a selected pine stand in Raco, MI. A sensitivity analysis is performed to characterize the response of coniferous and deciduous forest stands to a multifrequency and multipolarization INSAR in order to determine an optimum system configuration for remote sensing of forest parameters 相似文献
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直接地理编码与星载干涉SAR测高不确定度的等效性分析 总被引:1,自引:0,他引:1
现有的考虑地球曲率影响的INSAR测高模型主要有星载干涉SAR测高模型和直接地理编码两种。星载干涉SAR测高模型首先利用SAR干涉获取非模糊干涉相位,然后根据考虑地球曲率的空间几何关系直接计算地形高度。而直接地理编码模型则是在SAR干涉获取非模糊干涉相位的基础上,利用两个斜距方程和一个多普勒方程给出地面点的3维坐标值。由于两种模型得到地形高程的途径不同,因此很难直接比较这两种模型的地形测高不确定度。该文在采用矩阵形式推导出直接地理编码模型地形高程不确定度显示表达式的基础上,通过引入斜距平面坐标系,定量化地证明了直接地理编码模型的高程测量不确定度公式与考虑地球曲率的SAR干涉测高模型的测高不确定度公式是相同的,从而说明了这两种模型在用于地形高程测量时具有相同的精度。最后采用计算机仿真验证了理论分析的正确性。 相似文献