2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)最新文献_第9页

Endmember-based in-scene atmospheric retrieval (EMISAR) 基于端元的场景大气检索(EMISAR)

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1367962

E. M. Winter

{"title":"Endmember-based in-scene atmospheric retrieval (EMISAR)","authors":"E. M. Winter","doi":"10.1109/AERO.2004.1367962","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367962","url":null,"abstract":"The Aerospace Corp. in-scene atmospheric compensation (ISAC) algorithm offers the ability to remove the effects of the atmosphere on long wave infrared (LWIR) hyperspectral data using only the image data itself. The ISAC algorithm attempts to find blackbody pixels in the data and then uses the known spectral signature of a blackbody to correct the data. The most common examples of blackbodies in LWIR data are vegetation and water. While it has been applied successfully to a wide variety of data, the ISAC algorithm can fail when there is little or no vegetation or water in the scene. In this case, the algorithm will find some other material as a blackbody and this can result in an error in the correction process. The EMISAR algorithm is based on the ISAC method but offers an alternative approach that allows the use of other known materials. The data is first transformed to apparent emissivity, and then the spectral endmembers are found in the scene. This approach has the advantage of finding the true blackbodies in the scene (vegetation and water pixels with high fractional abundances), and can do it autonomously. It also can be used with scenes without vegetation, if the spectrum of some scene material is known.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"272 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115598525","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

The New Horizons high gain antenna: reflector design for a spin-stabilized bus at cryogenic temperatures 新视野高增益天线:低温下自旋稳定总线的反射器设计

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1367697

R. Schulze, S. Hill

引用次数: 12

Satellite communications in W-band: experimental set-up for channel characterization w波段的卫星通信:信道特性的实验设置

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1367629

A. de Luise, A. Paraboni, M. Ruggieri

引用次数: 1

Integration of material-based simulation into prognosis architectures 将基于材料的模拟集成到预测体系结构中

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1368192

L. Nasser, R. Tryon

引用次数: 2

Similarity-based modeling of aircraft flight paths 基于相似度的飞机飞行路径建模

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1367933

J. Mott, M. Pipke

{"title":"Similarity-based modeling of aircraft flight paths","authors":"J. Mott, M. Pipke","doi":"10.1109/AERO.2004.1367933","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367933","url":null,"abstract":"Modeling methods based on historical data can be used to model the values of parameters describing the flight paths of both military and commercial jet aircraft. Flight path parameters that are modeled typically include: pilot inputs such as the positions of the stick or control column and control wheel, power levers, rudder pedal, and controls for the slats, spoilers, stabilizer, and landing gear; control surface and controller responses such as the positions of the ailerons, elevators, flaps, rudder, slats, spoilers, stabilizer, and fuel flows; and aircraft responses such as airspeed, altitude, angle of attack, acceleration components, pitch, roll, yaw, the speeds of the low-pressure and high-pressure turbines, and exhaust gas temperatures. The utility of the models lies in their ability to confirm normal behavior and to detect abnormal behavior of control surfaces and engine systems during takeoff, cruise, and landing. Examples of several methods applied to a newly manufactured military jet to confirm acceptance test results during an entire flight are illustrated. Also illustrated are examples of several methods applied to the analysis of a commercial jet aircraft incident involving a control surface failure during a landing approach, an analysis that illustrates the capability of the method to support fault isolation. One of the versions, a similarity-based modeling method, exhibits a superior ability to achieve the intended purposes.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114530864","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: 4

Technology development for future very large observatories 未来大型天文台的技术发展

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1368243

J. Dooley

引用次数: 0

Uplink array system of antennas for the Deep Space Network 深空网络天线上行阵列系统

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1367715

F. Amoozegar, L. Paal, J. Layland, R. Cesarone, V. Jamnejad, A. Silva, D. Losh, B. Conroy, T. Cornish

{"title":"Uplink array system of antennas for the Deep Space Network","authors":"F. Amoozegar, L. Paal, J. Layland, R. Cesarone, V. Jamnejad, A. Silva, D. Losh, B. Conroy, T. Cornish","doi":"10.1109/AERO.2004.1367715","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367715","url":null,"abstract":"Recently, arraying of large or small and distributed reflector antennas for uplink applications has attracted attention for a capability upgrade to the Deep Space Network (DSN). This interest is driven by the desire to maximize the usefulness of existing DSN large apertures in case of spacecraft emergency and to develop the necessary knowledge of how the array of small and distributed reflector antennas can meet other future uplink throughput needs. The primary challenge for uplink arraying of distributed reflector antennas for deep space applications is the lack of feedback from deep space within a reasonably short period. Furthermore, the individual reflectors (and their transmitter subsystems) are thousands of wavelengths apart, which make the phase coherence of individual transmitted signals an extremely challenging task. Because of the return light time constraints, all closed-loop calibrations and relative phase adjustments for any coherent combination of signals from individual antennas be conducted no farther than near-Earth orbits. This paper discusses the large array background, scope, and evolution, and some of the lessons learned from preliminary studies of the uplink array.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114996700","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

A study of learning curve impact on three identical small spacecraft 三种相同小型航天器的学习曲线冲击研究

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1368215

G. Chen, D. McLennan

{"title":"A study of learning curve impact on three identical small spacecraft","authors":"G. Chen, D. McLennan","doi":"10.1109/AERO.2004.1368215","DOIUrl":"https://doi.org/10.1109/AERO.2004.1368215","url":null,"abstract":"We present the preliminary result of the study on the learning curve impact on three identical small spacecraft. Resources spent on concept development and design can be characterized as \"nonrecurring cost\" because it is not needed for future units. Nonrecurring cost primarily depends on the mission requirement, and in the case of ST-5, the inherent technological complication. However, recurring cost, the effort and resource spent in building and testing every unit of spacecraft, may be significantly affected by the \"learning curve effect\", due to the complicated structure of spacecraft or subsystems, as well as the uniqueness of aerospace products. For multispacecraft missions, recurring cost is one of our main concerns. Our research deals with the learning curve impact on the three ST-5 small satellites, including the impact to the entire spacecraft and the impact to primary subsystems, although a majority of ST-5 funding is contributed toward nonrecurring cost. This study is important and useful in assessment of NASA's future multi-spacecraft missions. It may help provide a more accurate estimate of the mission cost and give us an insight leading to possible cost reduction for the future multi-spacecraft missions.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116940496","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: 5

Comparison of VDL modes in the terminal domain 终端域中VDL模式的比较

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1367939

R.W. Murawski, S. Bretmersky, V. Konangi

引用次数: 4

Communications architecture for space-based sensor networks 天基传感器网络的通信体系结构

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1367723

L. Clare, J.L. Gao, E. Jennings, C. Okino

{"title":"Communications architecture for space-based sensor networks","authors":"L. Clare, J.L. Gao, E. Jennings, C. Okino","doi":"10.1109/AERO.2004.1367723","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367723","url":null,"abstract":"Numerous planned and proposed future space exploration missions employ multiple spacecraft that perform multipoint sensing. Distributed space-based sensing missions can significantly benefit from incorporation of cross-link communications capabilities, thereby forming space-based networks, by enabling continuous access to any/all spacecraft via a single ground contact, real-time coordinated observations, and autonomous in situ processing within a spatial neighborhood of spacecraft. We present a communications architecture for space-based sensor networks. Because of the large inter-spacecraft distances, directional antennas are used, with a single half-duplex transceiver per spacecraft to achieve low cost. Orbital motion induces a dynamic albeit predictable geometry (and topology) among the spacecraft. Primary offered traffic is sensor telemetry destined to the Earth ground station, although other traffic patterns are also treated. We present a technique that derives the link activation schedule (transmit/receive mode and communications neighbor selection) and routes used for efficient traffic relay through the network, leveraging the Florens and McEliece algorithm for tree networks. An illustrative example is presented, and throughput and latency performance are evaluated. An extension to the networking method is described that is traffic adaptive.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"53 29","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120809201","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