2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)最新文献_第8页

Hypothetical worst case solar particle event doses in LE0 假设最坏情况太阳粒子事件剂量在LE0

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1367645

L. Townsend, J. L. Hoff, D. Stephens

引用次数: 4

Sensor performance comparison of HyperSpecTIR instruments 1 and 2 HyperSpecTIR仪器1和2的传感器性能比较

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1117/12.543066

C. Jengo, J. Laveigne

{"title":"Sensor performance comparison of HyperSpecTIR instruments 1 and 2","authors":"C. Jengo, J. Laveigne","doi":"10.1117/12.543066","DOIUrl":"https://doi.org/10.1117/12.543066","url":null,"abstract":"SpecTIR Corporation has constructed a second copy of their HyperSpecTIR (HST) instrument, with modifications made to various mechanical, electrical, and optical systems. The first instrument (HST1) has been operating for several years aboard multiple platforms, and a sizable archive of imagery has been generated. Using this archive as a baseline, HST2 data have been evaluated to measure expected performance gains versus actual gains. The basic instrument specifications remain unchanged: 227 unique spectral channels from 450-2450nm with 8-12nm FWHM, 1 milliradian IFOV, 256 element cross-track scanning, up to 14 bit digitization, and beam steering optics for image stabilization. Notable changes in HST2 include AR coating of the SWIR FPA, miniaturization of the electronics, and integration of control and data processing computers within the sensor so that it may be used in a pod or UAV. Sufficiently clear data over a single study area does not exist, so data from the spectrally similar areas of Cuprite and Goldfield, Nevada are used to compare the performance of the two instruments. While AR coating of the SWIR focal plane and other improvements to HST2 have improved signal-to-noise performance, these gains are traded off for a shorter integration time allowing for faster and a greater volume of data collection. An attempt to objectively measure spectral image data quality using spectral similarity values and determining the inherent dimensionality of the data reveal similar spectral performance of the instruments under present operational modes.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"66 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":"125631183","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: 15

Are software COTS solutions an affordable alternative 软件COTS解决方案是一种可负担的替代方案吗

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1368227

A. Minkiewicz

引用次数: 6

L2-James Webb Space Telescope operationally friendly environment? l2 -詹姆斯·韦伯太空望远镜运行环境友好?

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1367595

J. Gal-Edd, C. Fatig

{"title":"L2-James Webb Space Telescope operationally friendly environment?","authors":"J. Gal-Edd, C. Fatig","doi":"10.1109/AERO.2004.1367595","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367595","url":null,"abstract":"One of the key components for James Webb Space Telescope (JWST) to meet its science goals is the second Lagrange point (L2) environment. This 'operationally friendly' environment provides JWST a dark, cold, and stable orbit to view the first starlight of the Universe. The environment assists the science instruments with passive cooling, limited stray light, and large contact times with Earth to increase the efficiency of the JWST. Now that JWST is moving into the design/construction phase, we are finding that the initial concepts now require a more detailed examination. We are finding that L2 has some issues that impact cost and operational friendliness. This paper will address some of these L2 environment challenges currently being reviewed: cosmic ray environment, communications, and orbit maintenance and determination. To address the above L2 environment concerns, the JWST spacecraft and science planning system requires adjustment to the onboard 'event driven' planning. As the spacecraft buildup continues, the challenges of communicating from L2 will be met so that JWST will see the first starlight in the Universe. The communication items will be covered in other papers during this conference.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"14 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":"132113999","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

Contrasting approaches to the validation of helicopter HUMS - a military user's perspective 直升机HUMS验证的对比方法——军事用户的视角

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1368193

J. Cook, J. Gourlay, L. Boardman

{"title":"Contrasting approaches to the validation of helicopter HUMS - a military user's perspective","authors":"J. Cook, J. Gourlay, L. Boardman","doi":"10.1109/AERO.2004.1368193","DOIUrl":"https://doi.org/10.1109/AERO.2004.1368193","url":null,"abstract":"There are various routes to system validation for helicopter health and usage monitoring systems (HUMS). Up-front validation through extensive test and qualification procedures is one approach, popular with aircraft operators seeking to extract maintenance credits from reluctant Design Authorities (DAs), but this is a costly and time-consuming avenue to take. An alternative system validation option is through accumulation of in-service experience and verification by demonstrated reliability. This approach is suitable for operators seeking to realise operational benefits such as predictive maintenance and increased operational availability, but may never win full support from the aircraft DA. The United Kingdom Ministry of Defence (UKMOD) is engaged in several simultaneous HUMS introduction programmes, involving examples of both validation methodologies. An AgustaWestland HUMS capability is being introduced across the EH101 Merlin fleets with extensively tested and qualified software, fully integrated with the flight control systems and flight-critical sensors and implemented through the 'glass cockpit' modular avionics. This system has demonstrated strengths and weaknesses fundamental to the design ethos. In parallel, a Smiths aerospace generic HUMS capability is being retrofitted to the fleets of four helicopter platforms - Chinook, Sea King, Puma and Lynx. This monitoring system is qualified and tested to a lower software integrity level than the Merlin system, has a stand-alone pilot interface and is isolated from flight-critical systems and sensors. In the four years since fielding, this programme has encountered a number of significant successes and obstacles. The Assistant Directorate of aircraft integrity monitoring (AD AIM), a specialist support unit within the corporate UKMOD is in the unique position of having full visibility of both systems. This paper describes the steps taken, the lessons learned and the achievements made in validating and verifying HUMS from a user's perspective.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"7 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":"132494232","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

An authentication service against dishonest users in mobile ad hoc networks 针对移动自组织网络中不诚实用户的认证服务

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1367725

E. C. Ngai, Michael R. Lyu, R. T. Chin

{"title":"An authentication service against dishonest users in mobile ad hoc networks","authors":"E. C. Ngai, Michael R. Lyu, R. T. Chin","doi":"10.1109/AERO.2004.1367725","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367725","url":null,"abstract":"A mobile ad hoc network is a collection of wireless mobile nodes, dynamically forming a temporary network without the use of any existing network infrastructure or centralized administration. It is an emerging technology for civilian and military applications. However, security in mobile ad hoc networks is hard to achieve due to the vulnerability of the links, the limited physical protection of the nodes, and the absence of a certification authority or centralized management point. Similar to other distributed systems, security in mobile ad hoc networks usually relies on the use of different key management mechanisms. We exploit characteristics of an ad hoc network and present our authentication service to protect network security in the presence of dishonest users. Nodes originally trustable in the network may become malicious due to sudden attacks, so an adequate security support for authentication to deal with dishonest users who issue false public key certificates is crucial. We describe a new authentication service with a well-defined network model and a trust model. These models allow nodes in the network to monitor and rate each other with an authentication metric. We also propose a novel public key certificate operation, incorporating with a trust value update algorithm in public key authentication. The authentication service we propose is able to discover and isolate dishonest users in the network. Finally, we evaluate the proposed solution through simulation to demonstrate the effectiveness of the scheme.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"52 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":"130452591","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: 44

Cost estimation: more than an analytical tool 成本估算:不仅仅是一个分析工具

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1367707

Lt. Amy Salas

{"title":"Cost estimation: more than an analytical tool","authors":"Lt. Amy Salas","doi":"10.1109/AERO.2004.1367707","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367707","url":null,"abstract":"The U.S. government has guided the defense industry into taking a more commercial approach in many areas of the acquisition process. From capability based system requirements documents to contract management approach, contractors have been placed in a role of greater responsibility with less oversight. With this added responsibility, cost estimation in all phases of the development and production becomes critically important, as the contractor assumes more risk in advanced system procurement with unexpected challenges. Unfortunately the 'Holy Grail' of analytical cost estimation and improvements to methodologies is not the key to solving program office budget overruns, it is only an estimating tool. Cost estimation faces many challenges including: access to historical data, validity and uncertainty of data, limited time to develop estimates and immaturity of requirements. These challenges are especially exacerbated for space systems. Military and commercial systems alike face these challenges, but methodology is driven by different factors. For commercial estimations, a sound business approach is the driving factor to produce an estimate that is not only stay within budget, but also produce a competitive risk-adjusted return. Military estimations are mostly concerned with allowing for enough error to stay within the boundaries of fiscally constrained resources while being flexible enough to allow for iterations of design and requirements. This paper intends to explore the different root causes of cost estimation error in government acquisitions, focusing on space programs: including the history of cost estimations, drivers of error and ways to close the gap between budgeted and actual costs.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"2 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":"130776653","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: 10

Design, fabrication and testing of coplanar waveguide transmission lines for use in RF MEMS switches 用于射频MEMS开关的共面波导传输线的设计、制造和测试

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1367692

J. Rock, T. Hudson, M. Buncick, E. Tuck, M. Kranz

引用次数: 1

An update on NASA's Astronomical Search for Origins program 美国宇航局天文搜索起源计划的最新进展

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1368241

M. Devirian

引用次数: 1

Design and verification of a mechanical system for magnetospheric mapping missions 磁层测绘机械系统的设计与验证

2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720) Pub Date : 2004-03-06 DOI: 10.1109/AERO.2004.1367609

P. Rossoni

引用次数: 0