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M. Pietrella A. Pignalberi M. Pezzopane A. Pignatelli A. Azzarone R. Rizzi 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2018,61(10):2569-2584
Three-dimensional (3-D) electron density matrices, computed in the Mediterranean area by the IRI climatological model and IRIEup and ISP nowcasting models, during some intense and severe geomagnetic-ionospheric storms, were ingested by the ray tracing software tool IONORT, to synthesize quasi-vertical ionograms. IRIEup model was run in different operational modes: (1) assimilating validated autoscaled electron density profiles only from a limited area which, in our case, is the Mediterranean sector (IRIEup_re(V) mode); (2) assimilating electron density profiles from a larger region including several stations spread across Europe: (a) without taking care of validating the autoscaled data in the assimilation process (IRIEup(NV)); (b) validating carefully the autoscaled electron density profiles before their assimilation (IRIEup(V)).The comparative analysis was carried out comparing IRI, IRIEup_re(V), ISP, IRIEup(NV), and IRIEup(V) foF2 synthesized values, with corresponding foF2 measurements autoscaled by ARTIST, and then validated, at the truth sites of Roquetes (40.80°N, 0.50°E, Spain), San Vito (40.60°N, 17.80°E, Italy), Athens (38.00°N, 23.50°E, Greece), and Nicosia, (35.03°N, 33.16°E, Cyprus). The outcomes demonstrate that: (1) IRIEup_re(V), performs better than ISP in the western Mediterranean (around Roquetes); (2) ISP performs slightly better than IRIEup_re(V) in the central part of Mediterranean (around Athens and San Vito); (3) ISP performance is better than the IRIEup_re(V) one in the eastern Mediterranean (around Nicosia); (4) IRIEup(NV) performance is worse than the IRIEup(V) one; (5) in the central Mediterranean area, IRIEup(V) performance is better than the IRIEup_re(V) one, and it is practically the same for the western and eastern sectors.Concerning the overall performance, nowcasting models proved to be considerably more reliable than the climatological IRI model to represent the ionosphere behaviour during geomagnetic-ionospheric storm conditions; ISP and IRIEup(V) provided the best performance, but neither of them has clearly prevailed over the other one. 相似文献
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Recent studies on human missions to Mars suggest revisiting the parameters that have the most important impact on the complexity, the initial mass in low Earth orbit, the risks and the development costs for the first journey to the red planet. In the last NASA reference mission, a trade tree is proposed. 相似文献
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详细介绍基于在系统可编程逻辑器件的实验仪的设计与实现,并对在系统可编程逻辑器件的设计流程进行论述。 相似文献
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TMS320VC5402片外存储器扩展及自举引导程序的设计 总被引:1,自引:0,他引:1
刘苗 《沈阳航空工业学院学报》2006,23(3):57-59
针对低功耗、高性能数字信号处理芯片TMS320VC5402片内RAM的易失性以及片外非易失性但存储器运行速度太慢的弊端,介绍了VC5402的存储器资源配置,提供了一种实用的扩展存储器设计方案。利用两块完全相同的快速SRAM,分别分配到数据和程序空间,并利用FLASH存储器SST39VF400A在系统编程技术,设计和编写符合系统要求的上电引导程序的方法。另对TMS32OVC5402的存储器资源配置,提供了一种实用的扩展存储器设计方案,在这种存储器资源配置的基础上,利用FLASH存储器的在系统编程技术,设计和编写符合系统要求的上电引导程序的方法。 相似文献
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利用 USB接口芯片 ISP1 5 81 ,通过接收、存储和循环输出仿真数据的方法。实现了多通道仿真功能 ,并可以接收阵列信号处理器的输出数据。文中介绍硬件系统结构和实现方法。USB驱动程序的开发流程、PC应用程序和 89C5 2固件程序的功能和程序流程 相似文献
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CCSDS(Consultative Committee for Space Data Systems,空间数据系统咨询委员会)SLE(Space Link Extension,空间链路拓展)网络协议体系模型中,一个服务实例只支持建立一个物理通信链路,造成上层应用与下层链路耦合过强,存在一定的安全隐患。针对此问题,设计了基于冗余连接机制的SLE网络协议体系模型,该模型在现有的SLE网络协议体系模型中增加了逻辑连接层,支持单一服务实例同时使用多个物理链路进行空间数据传输,可根据多连接状态重新设计TML(Transport Mapping Layer,传输映射层)状态变换关系以及数据传输模式。该模型能够兼容现有的SLE网络传输体系模型,提高SLE服务的可靠性。 相似文献
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