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M. Grasso A. Renga G. Fasano M.D. Graziano M. Grassi A. Moccia 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(11):3909-3923
The paper focuses on space system design aspects related to an end-to-end demonstration mission, aiming at showing the feasibility of a Formation Flying Synthetic Aperture Radar (FF-SAR) with microsatellite class platforms (~100 kg). Trajectory design approaches that can fulfil payload requirements are addressed to enable selected FF-SAR applications. The exploitation of these applications relies on suitable combinations of FF-SAR techniques like Signal-to-Noise Ratio (SNR) enhancement, High-Resolution Wide Swath (HRWS) SAR imaging, and Coherence Resolution Enhancement (CRE). In this framework, a cluster of 3 micro-satellites, working in X-band, flying in a Low Earth Orbit (LEO) close-formation, has been designed as a candidate end-to-end system demonstration mission. One satellite embarks a Transmitting-Receiving (Tx/Rx) radar, i.e. it is a monostatic SAR. The other two satellites are Receiving-only platforms. Critical design aspects related to spacecraft subsystems and formation-flying analysis are addressed to confirm the technical feasibility of the spaceborne distributed system implementing the FF-SAR principle. 相似文献
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文章介绍了卫星数据图像的存储,论述几种集群服务器的负载策略,提出一种自适应的负载均衡策略,并对以往策略进行了对比。对分布式分包路由(DPR)技术作了深入的分析,作者在测试评估的过程中,给出一种新的集群服务器方案。 相似文献
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分布式卫星精确构形保持变结构控制 总被引:4,自引:1,他引:3
分布式卫星构形精确保持是实现分布式卫星任务的关键技术。在控制模型不精确和摄动力不确定的条件下,经典控制方法在鲁棒性、动态品质和静态指标的权衡等方面存在不足。本文利用变结构控制方法,设计了分布式卫星精确构形保持的控制器,使控制方法对摄动干扰、模型不确定等具有鲁棒性,因而使构形保持方法在参考轨道存在小偏心率、摄动力存在等非理想情况下仍然可以正常进行。利用高精度动力学仿真环境,对方法的先进性进行了检验。 相似文献
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《中国航空学报》2020,33(1):308-323
Distributed Integrated Modular Avionics (DIMA) develops from Integrated Modular Avionics (IMA) and realizes distributed integration of multiple sub-function areas. Time-triggered network provides effective support for time synchronization and information coordination in DIMA systems. However, inconsistency between processing resources and communication network destroys the time determinism benefiting from partitions and time-triggered mechanism. To ensure such time determinism and achieve guaranteed real-time performance, system design should collectively provide a global communication scheme for messages in network domain and a corresponding execution scheme for partitions in processing domain. This paper firstly establishes a general DIMA model which coordinates partitioned processing and time-triggered communication, and then proposes a hybrid scheduling algorithm using Mixed Integer Programming to produce feasible system schemes. Furthermore, incrementally integrating new functions causes upgrades or reconfigurations of DIMA systems and will generate integration cost. To control such cost, this paper further develops an optimization algorithm based on Maximum Satisfiability Problem and guarantees that the scheduling design for upgraded DIMA systems inherit their original schemes as much as possible. Finally, two typical cases, including a simple fully connected DIMA system case and an industrial DIMA system case, are constructed to illustrate our DIMA model and validate the effectiveness of our hybrid scheduling algorithms. 相似文献