2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)最新文献_第9页

Flight mishap prevention for UAVs 无人机飞行事故预防

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931244

R.D. Colgren, T. Johnson

{"title":"Flight mishap prevention for UAVs","authors":"R.D. Colgren, T. Johnson","doi":"10.1109/AERO.2001.931244","DOIUrl":"https://doi.org/10.1109/AERO.2001.931244","url":null,"abstract":"For Uninhabited Air Vehicles (UAVs) to achieve operational levels of flight safety comparable to those of piloted aircraft, it is important to replicate the critical skills and predictive capabilities of the pilot to ensure proper flight mode selection and prioritization of tasking. Each individual combination of modes must be able to accommodate both predetermined as well as unanticipated causes of uncertainty. The system must adapt to these changes based on sensory inputs, as well as be robust against uncertainties that have not been sensed or directly measured by the system. The purpose of Technologies for Reliable Autonomous Control (TRAC), a joint Lockheed Martin Aeronautics Company/General Electric/Jet Propulsion Laboratory mission management architecture, is to autonomously accomplish this complex mission and subsystem management task. To do this, it is desirable to provide \"outer-loop\" compensation for larger sources of disturbances that may require corrective maneuvers, mode switching, or changes to the command inputs to the flight control system. Flight Envelope Protection is one such feature. Based on our analysis of recent UAV data, emergency procedures account for about 26% of mishaps, while errors in operating procedures account for about 10% of mishaps. Thus, Flight Envelope Protection could prevent up to about 36% of mishaps. While there are many points of similarity between UAV Flight Envelope Protection (FEP) and FEP for manned aircraft, a number of new issues arise in the UAV case. Hence, this is not straightforward extension of existing techniques.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"11 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":"121380136","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

ICDM: an architecture and toolkit in support of agent-based, decision-support applications ICDM:支持基于代理的决策支持应用程序的体系结构和工具包

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931301

K. Pohl

引用次数: 0

The computer replacement program for the joint surveillance target attack radar system 联合监视目标攻击雷达系统的计算机替换方案

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931223

B. Kish, W. Gibboney, M. Veth, M. Morán

{"title":"The computer replacement program for the joint surveillance target attack radar system","authors":"B. Kish, W. Gibboney, M. Veth, M. Morán","doi":"10.1109/AERO.2001.931223","DOIUrl":"https://doi.org/10.1109/AERO.2001.931223","url":null,"abstract":"This paper presents development and testing results of the Computer Replacement Program (CRP) for the Joint Surveillance Target Attack Radar System (Joint STARS). Joint STARS, which consists of a modified Boeing 707-300 (E-8C) developed by Northrop Grumman and Common Ground Stations developed by Motorola, provides theater commanders near real-time surveillance and attack support information on moving and stationary targets. Diminishing manufacturing sources and an emphasis on life-cycle cost reduction required a modernization program that took maximum advantage of commercial equipment. The primary program objectives were maximizing marketplace support, reducing life-cycle costs and facilitating cyclic upgrades. CRP implemented this via a commercial off-the-shelf-based open architecture. The Computer Replacement Program met all its development objectives and will be fielded on the entire 15-aircraft Joint STARS fleet. Lessons learned included applying innovative acquisition processes in an open architecture, adapting to processes while under schedule pressure, ensuring early operational tester involvement, and estimating laboratory and ground testing in addition to flight-testing. The views expressed in this paper are those of the authors and do not represent views of the U.S. government or their contractors.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"24 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":"126365566","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: 1

Multiprocessor digital signal processing on Earth orbiting scatterometers 地球轨道散射计的多处理器数字信号处理

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931182

A. Bachmann, D. Clark, J. Lux, R. Steme

{"title":"Multiprocessor digital signal processing on Earth orbiting scatterometers","authors":"A. Bachmann, D. Clark, J. Lux, R. Steme","doi":"10.1109/AERO.2001.931182","DOIUrl":"https://doi.org/10.1109/AERO.2001.931182","url":null,"abstract":"The implementation of a Multi Digital Signal Processor for radar return analysis on a Ku-Band Earth orbiting scatterometer is discussed. Historically, radar signal processing on scatterometers has been implemented with discrete components, Field Programmable Gate Arrays (FPGA)and Application Specific Integrated Circuits (ASIC). These methods are expensive due to long development times, expensive tools, and their lack of modularity. The system presented in this paper uses a radiation tolerant, space qualified version of a commercial general purpose DSP (ADSP-21020) to perform the radar signal processing functions. This approach allows the use of development tools such as compilers, libraries, evaluation boards and emulators. The presented system uses multiple processors interconnected with IEEE-1355 high-speed links to provide the computational power necessary. Operating systems such as Virtuoso provide core capabilities to facilitate scalability, which is important to accommodate changes in functional or performance requirements that inevitably occur late in the development cycle, or even on orbit. A testbed was assembled using a combination of commercial DSP hardware and spaceflight components to evaluate the proposed multiprocessing approaches. Test results of real-time radar echo processing are presented, as well as proposed designs for future investigation.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"9 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":"121483897","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

X2000/IFDP system engineering process for risk management X2000/IFDP系统工程流程的风险管理

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931739

T. Hoffman, C. Guiar

引用次数: 0

Prediction and adaptation of satellite channels with weather-induced impairments 预报和适应卫星频道与天气引起的损害

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931351

J.P. Choi, V. Chan

{"title":"Prediction and adaptation of satellite channels with weather-induced impairments","authors":"J.P. Choi, V. Chan","doi":"10.1109/AERO.2001.931351","DOIUrl":"https://doi.org/10.1109/AERO.2001.931351","url":null,"abstract":"Efficiency improvements using prediction and adaptation methods over satellite channels with weather-induced impairments are presented. Considering scintillation and rain attenuation as two dominant factors for signal fading over satellite-Earth paths over 10 GHz, we develop statistical and spectral analyses of these processes, and obtain simple linear estimators for received signal attenuation using autoregressive (AR) models. Using these estimators, we present results where we can predict the received signal attenuation within /spl plusmn/0.5 dB 1 second ahead and within /spl plusmn/1.0 dB 4 seconds ahead. For adaptation, we change signal transmission power, modulation symbol size, and/or code rate adaptively. In particular, we introduce a continuous power control and discrete rate control strategy, through which we build a set of modulation/code states, and discretely change the modulation symbol size and the code rate from state to state. Within each state, continuous power contral is implemented. The quantitative analysis of power consumption indicates that there is a substantial gain in performance with the adaptive schemes, e.g., as much as 13 dB on a lightly rainy day.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"8 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":"127440495","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

A spaceborne L-band radiometer-radar concept for land and ocean surface monitoring 用于陆地和海洋表面监测的星载l波段辐射计-雷达概念

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931502

E. Njoku, Yunjin Kim, M. Spencer, W. Tsai, Y. Rahmat-Samii, M. Thomson

{"title":"A spaceborne L-band radiometer-radar concept for land and ocean surface monitoring","authors":"E. Njoku, Yunjin Kim, M. Spencer, W. Tsai, Y. Rahmat-Samii, M. Thomson","doi":"10.1109/AERO.2001.931502","DOIUrl":"https://doi.org/10.1109/AERO.2001.931502","url":null,"abstract":"An L-band radiometer-radar concept has been studied for spaceborne remote sensing of land surface soil moisture, freeze-thaw state, and ocean surface salinity. The integrated design provides simultaneous passive and active measurements with potential for enhanced geophysical retrieval accuracy and spatial resolution. The design takes advantage of cost savings achievable using shared subsystems and hardware. The baseline system concept has been evaluated to determine the feasibility of the technical approach and as a point of departure for system trade-offs. The unique features of this concept are the integration of the radiometer and radar sensors, the use of a deployable-mesh conically scanned reflector antenna, and the use of unfocused synthetic aperture radar (SAR) processing. Taken together, these features represent a significant departure from conventional radiometer, scatterometer, and SAR approaches. The conical wide-swath scan is a desirable feature that provides constant incidence angle and antenna pattern characteristics across the swath, simplified data processing (passive and active), and frequent global sampling. The concept is targeted for a low-cost, short-development-cycle mission, suitable for NASA's Earth System Science Pathfinder (ESSP) series.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"34 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":"124425808","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

Onboard guarded software upgrading: motivation and framework 板载保护软件升级:动机和框架

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931201

A. Tai, L. Alkalai, S. Chau

引用次数: 1

Local defect study of membrane antennas and reflectors 膜天线和反射器局部缺陷研究

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931262

C. Jenkins, J. Ash, D. Marker

{"title":"Local defect study of membrane antennas and reflectors","authors":"C. Jenkins, J. Ash, D. Marker","doi":"10.1109/AERO.2001.931262","DOIUrl":"https://doi.org/10.1109/AERO.2001.931262","url":null,"abstract":"One of the great enabling technologies for 21st Century space science missions will be gossamer spacecraft. Since resolution is proportional to diameter at the diffraction limit, larger antennas and optic apertures mean greater opportunities for increasing scientific knowledge. Due to finite launch vehicle capacity (launch mass and volume), these large (>12 m) apertures must also be ultra-low mass. This implies some sort of membrane/ inflatable structure. The current paper discusses the effects of local defects on reflector performance. Unlike classical glass optics for example, membrane apertures cannot be ground and polished to precision tolerances. The manufacturing process must account for minimum thresholds of surface smoothness and mechanical property irregularities. For example, sufficient numbers of small regions of thickness or Young's modulus irregularities can lead to unacceptable surface error. This paper reports on analysis of such local defects on the surface precision of gossamer apertures. A nonlinear finite element code is used to model the effect of single and multiple defects in curved membranes. Two measures of performance are used. First, we compute the deviation of the local slope for a given defect geometry and property irregularity. Secondly, we compute the spatial influence function of the defect both on the neighboring uniform membrane, as well as on nearby like defects. Indications of manufacturing tolerances required to achieve minimum acceptable performance are discussed.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"444 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":"133659871","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

Atmospheric electron X-ray spectrometer development 大气电子x射线光谱仪的研制

2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) Pub Date : 2001-03-10 DOI: 10.1109/AERO.2001.931715

J. Feldman, J. Wilcox, T. George, N. Bridges, D. Barsic, A. Scherer

引用次数: 5