2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)最新文献_第10页

Design of optical phased array beam steering with limited dispersion 有限色散光相控阵光束导向设计

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931390

P. McManamon, E. Watson

{"title":"Design of optical phased array beam steering with limited dispersion","authors":"P. McManamon, E. Watson","doi":"10.1109/AERO.2001.931390","DOIUrl":"https://doi.org/10.1109/AERO.2001.931390","url":null,"abstract":"This paper shows how the dispersion associated with optical phased array beam steering can be limited to moderate values of 20 to 80 times the diffraction limit even for very large angle beam steering. Much of the remaining factor of 20-80 may be correctable using digital techniques. A significant obstacle associated with widespread implementation of optical phased array beam steering is the wavelength dispersion associated with resets. We discuss optical phased array beam steering using resets of greater than one wavelength. By using larger resets the unfolded phase front for wavelengths other than the design wavelength can be maintained closer to a prism, thus limiting dispersion. This technique can be implemented with the variable period beam steering approach and the variable blaze beam steering approach. One way to implement the variable blaze beam steering approach is using movable lenslets. This method of implementation is amenable to large value resets, so it is an attractive method of implementation for this multiple wavelength reset, limited dispersion, beam steering technique. By using resets of multiple wavelengths and limiting the dispersion we will be able to steer passive, broadband, electrooptical sensors over wide angles using optical phased array technology.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130403145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Frequency bands for Mars in-situ communications 用于火星现场通信的频段

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931350

D. Hansen, M. Sue, C. M. Ho, M. Connally, T. Peng, R. Cesarone, W. Home

{"title":"Frequency bands for Mars in-situ communications","authors":"D. Hansen, M. Sue, C. M. Ho, M. Connally, T. Peng, R. Cesarone, W. Home","doi":"10.1109/AERO.2001.931350","DOIUrl":"https://doi.org/10.1109/AERO.2001.931350","url":null,"abstract":"The recent decision to send two rovers to Mars in 2003 has provided new direction for Mars exploration. To meet these future challenges, JPL is preparing the Deep Space Network and other communication systems to support the expected increase in Mars exploration activities. Toward this end, JPL is conducting studies to enhance communications and navigation capabilities on or around Mars for future Mars missions and is investing in hardware development for use by those missions. One such study is developing a multiple-access scheme and a frequency-utilization plan for in-situ communications and navigation. The results of this study will provide recommendations for developing communications hardware for future Mars missions, establishing interoperability processes and standards, ensuring access to the radio frequency spectrum for operations at Mars and for testing at Earth, and designing a communication and navigation infrastructure around Mars. This paper focuses on the selection of frequencies for local (\"in situ\") links at Mars. Various factors affecting the selection of frequencies, including link performance, propagation effects, and mission scenarios, are discussed.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"83 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116565957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Validation of theoretical GPS multipath bias characteristics 理论GPS多径偏置特性验证

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931362

J. M. Kelly, M. Braasch

引用次数: 14

MEMS based Sun sensor 基于MEMS的太阳传感器

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931388

C. Liebe, S. Mobasser

引用次数: 42

Dynamic bandwidth allocation in a satellite communication network 卫星通信网络中的动态带宽分配

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931352

T. Huynh, D.C. Gillen

{"title":"Dynamic bandwidth allocation in a satellite communication network","authors":"T. Huynh, D.C. Gillen","doi":"10.1109/AERO.2001.931352","DOIUrl":"https://doi.org/10.1109/AERO.2001.931352","url":null,"abstract":"Our work deals with ATM satellite communications networks employing DAMA, whose algorithm must be efficient and robust. Its efficiency ensures a fast response to a connection's demand for bandwidth. Its robustness ensures satisfaction of the connection's required QoS and its integrity under unpredictable traffic burstiness. Computational practicality dictates that only heuristic DAMA algorithms be implemented in an ATM satellite communications system. But these heuristic algorithms need be validated and benchmarked before they are fielded. In this work, we employ the orthogonal array experiment (or the Taguchi method) to allocate bandwidth in a satellite communications network. We also validate and benchmark the Taguchi assignments with the results obtained by mathematical optimization. This benchmarking process allows us to quantitatively assess the performance of our approach and is recommended to be employed when developing heuristic algorithms. The close agreement between the results produced by the orthogonal array experiment method and the conventional integer programming solution methods underscores the feasibility of the orthogonal array experiment approach.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128119002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Link and routing issues for Internet protocols in space 空间因特网协议的链路和路由问题

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931278

K. Hogie, E. Criscuolo, R. Parise

{"title":"Link and routing issues for Internet protocols in space","authors":"K. Hogie, E. Criscuolo, R. Parise","doi":"10.1109/AERO.2001.931278","DOIUrl":"https://doi.org/10.1109/AERO.2001.931278","url":null,"abstract":"The first step in using Internet protocols in space is to establish the basic Internet datagram delivery service over satellite RF links. This paper discusses the low-level data link and data routing issues related to using Internet protocols to support spacecraft communications. It covers issues related to layer 1 (physical), layer 2 (data link), and layer 3 (network). It does not cover layer 4 (transport) and above. At the physical layer, the paper presents various applications of forward-error-correction (FEC) coding techniques, such as convolutional coding and Reed-Solomon. It describes approaches for using these techniques in ways that are independent of the protocols used at the data link layer and above. At the data link layer, common, commercially available framing schemes are discussed along with how they can be easily deployed. A rationale is provided for the selection of HDLC/frame relay framing along with IETF multi-protocol encapsulation. At the network layer, the Internet protocol end-to-end addressability and routing is discussed in the context of space-based applications. Standard solutions for dealing with the intermittent and mobile links of satellites are also discussed. These include a discussion of Mobile IP and mobile routing protocols. Finally, deployment of these protocols in both spacecraft and ground systems are discussed. Details of current implementations by the Operating Missions as Nodes on the Internet (OMNI) project at NASA/GSFC using operational space and ground systems such as UoSAT-12 and TDRSS are also provided.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"11231 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131917994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 26

Radiation hardened memory development at Honeywell 霍尼韦尔的辐射硬化存储器开发

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931186

H. Kaakani

引用次数: 10

Internet-type protocol testing in a simulated small satellite environment 模拟小卫星环境下的互联网协议测试

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931279

S. Horan, Ruhai Wang

引用次数: 10

Multi-platform GMTI tracking for surveillance and reconnaissance coalition environments 用于监视和侦察联盟环境的多平台GMTI跟踪

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931511

R. Popp, H. Maney, J. Jones

{"title":"Multi-platform GMTI tracking for surveillance and reconnaissance coalition environments","authors":"R. Popp, H. Maney, J. Jones","doi":"10.1109/AERO.2001.931511","DOIUrl":"https://doi.org/10.1109/AERO.2001.931511","url":null,"abstract":"The focus of this paper is to describe several recent applications of multi-platform ground moving target indicator (GMTI) tracking technology for surveillance and reconnaissance coalition environments. As part of the U.S. Air Force's 1999 Joint Expeditionary Force experiment (JEFX), we demonstrated (in stand-alone mode) GMTI tracking technology for a simulated ground target scenario consisting of 20,000+ military and civilian ground vehicles and GMTI sensor data based on multiple U.S. and coalition radar simulators (i.e., U.S. Joint STARS and Global Hawk, U.K. ASTOR, French HORIZON, Italy CRESO). As part of NATO's Joint Project Optic Windmill (JPOW) V/Clean Hunter 2000 (CN00), we demonstrated the real-time operation of GMTI tracking technology in a live military coalition exercise environment. Two such systems were supported at JPOW V/CN00: (i) an on-board system consisting of the GMTI tracker ported to a DEC ALPHA on the Navy's P3 APY-6 platform, and used by operators to track ground targets based on GMTI data produced by the APY-6 radar system alone, and (ii) an off-board system consisting of the GMTI tracker ported to a Sun Quad Ultra 80 at NATO HQ AIRNORTH at Ramstein AFB Germany, and used to track ground targets based on real GMTI data produced by both the P3 APY-6 and the French HORIZON. In addition, simulated GMTI data from the JSTARS, Global Hawk, and ASTOR radar simulators was also produced and tracked based on a simulated ground target scenario consisting of 30,000+ military and civilian ground vehicles.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"475 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133472223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Development of a testbed for distributed satellite command and control 分布式卫星指挥控制试验台的研制

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931239

P. Zetocha, M. Brito

{"title":"Development of a testbed for distributed satellite command and control","authors":"P. Zetocha, M. Brito","doi":"10.1109/AERO.2001.931239","DOIUrl":"https://doi.org/10.1109/AERO.2001.931239","url":null,"abstract":"At the Air Force Research Laboratory's Space Vehicles Directorate we are investigating and developing architectures for commanding and controlling a cluster of cooperating satellites through prototype development for the TechSat-21 program. The objective of this paper is to describe a distributed satellite testbed that is currently under development and to summarize near term prototypes being implemented for cluster command and control. To design, develop, and test our architecture we are using eight PowerPC750 VME-based single board computers, representing eight satellites. Each of these computers is hosting the OSE/sup TM/ real-time operating system from Enea Systems. At the core of our on-board cluster manager is ObjectAgent. ObjectAgent is an agent-based object-oriented framework for flight systems which is particularly suitable for distributed applications. In order to handle communication with the ground as well as to assist with cluster management, we use the Spacecraft Command Language (SCL). SCL is also at the centerpiece of our ground control station and handles cluster commanding, telemetry decommutation, state-of-health monitoring, and Fault Detection, Isolation, and Resolution (FDIR). For planning and scheduling activities we are currently using ASPEN from NASA/JPL. This paper describes each of the above components in detail and then presents the prototypes being implemented.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"11 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133971116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8