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介绍了后方交会及支导线的计算方法，探讨了Casio Fx4500计算器程序的编制，说明后方交会法配合可编程计算程序在道路施工及其它测量放线过程中不仅克服了其路基不平等许多不便之处，而且大大提高了测量放线的速度和精度，值得推广应用。 相似文献
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John D. Bunton 《Experimental Astronomy》2004,17(1-3):251-259
When the SKA was proposed, a major technical obstacle to its feasibility was the cost of the correlator. Significant advances made in correlator design since then are described. These advances have made SKA correlator possible within reasonable cost constrains. At the same time performance issues with the proposed FX architecture have been addressed. 相似文献
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An FX correlator implementation for the SKAMP project is presented. The completed system will provide capabilities that match those proposed for the aperture plane array concept for the SKA. Through novel architecture, expansion is possible to accommodate larger arrays such as the 600-station cylindrical reflector proposals. In contrast to many current prototypes, it will use digital transmission from the antenna, requiring digital filterbanks and beamformers to be located at the antenna. This will demonstrate the technologies needed for all long baseline antennas in the SKA. 相似文献
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城市信息的提取是城市动态监测和分析的基础,而城市动态监测对社会发展和人类生活具有重要意义。本文基于三峡地区的SPOT-5遥感影像,以城市绿地和建筑物为研究对象,用ENVI FX影像处理软件,对实验区的绿地和建筑物进行多尺度影像分割信息提取。结果表明,采用多尺度分割技术提取高分辨率影像中地物的提取精度更高,并有效地避免了"椒盐现象"。 相似文献
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NASA is proposing a new receiving facility that needs to beamform broadband signals from hundreds of antennas. This is a similar problem to SKA beamforming with the added requirement that the processing should not add significant noise or distortion that would interfere with processing spacecraft telemetry data. The proposed solution is based on an FX correlator architecture and uses oversampling polyphase filterbanks to avoid aliasing. Each beamformer/correlator module processes a small part of the total bandwidth for all antennas, eliminating interconnection problems. Processing the summed frequency data with a synthesis polyphase filterbank reconstructs the time series. Choice of suitable oversampling ratio, and analysis and synthesis filters can keep aliasing below −39 dB while keeping the passband ripple low. This approach is readily integrated into the currently proposed SKA correlator architecture. 相似文献
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