{"title":"Modern antenna design concepts for satellite and personal communications","authors":"Y. Rahmat-Samii, D. Duan, M. Jensen","doi":"10.1109/AERO.1994.291185","DOIUrl":"https://doi.org/10.1109/AERO.1994.291185","url":null,"abstract":"The increasing demands placed upon antennas to provide wireless channels for satellite and personal communications systems has encouraged the development of sophisticated analysis and design techniques. This paper presents design concepts based upon recent advances associated with diffraction synthesis/analysis of dual offset reflector antennas for satellite communications as well as the application of the finite difference time domain (FDTD) approach for evaluating antennas for personal communications systems.<<ETX>>","PeriodicalId":223269,"journal":{"name":"Proceedings of 1994 IEEE Aerospace Applications Conference Proceedings","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131182724","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}
{"title":"Formation of dendrites: experimental observations","authors":"G. Stupian, N. Presser","doi":"10.1109/AERO.1994.291180","DOIUrl":"https://doi.org/10.1109/AERO.1994.291180","url":null,"abstract":"A recent failure investigation highlighted the potential for dendrite formation in many electronic environments. In general dendritic growth requires an electrical bias to drive, and a condensed medium to support the growth process. In practice the latter is often a contaminating liquid. We briefly review our experimental observations of how the chemical composition and dimensionality (i.e. a film versus a droplet) of the supporting medium affect the morphology, composition and rate of dendritic growth and consider how such information might be used as an aid in establishing the source of the contaminant.<<ETX>>","PeriodicalId":223269,"journal":{"name":"Proceedings of 1994 IEEE Aerospace Applications Conference Proceedings","volume":"216 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132551725","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}
{"title":"Particle interferometry in heavy ion collisions","authors":"F. B. Yano","doi":"10.1109/AERO.1994.291191","DOIUrl":"https://doi.org/10.1109/AERO.1994.291191","url":null,"abstract":"In this tutorial paper the method of Hanbury Brown and Twiss (HBT) (1956) used in optical and radiofrequency interferometry and its generalization to particle interferometry are reviewed. We give also an outline of how the HBT effect has been applied in the very active area of current research in heavy ion physics. The space time parameters of the collision region are determined from measurements of particle correlations to give important information about nuclear matter at high energy densities.<<ETX>>","PeriodicalId":223269,"journal":{"name":"Proceedings of 1994 IEEE Aerospace Applications Conference Proceedings","volume":"144 12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129525051","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}
{"title":"The minimal time detection algorithm","authors":"Sungwan Kim","doi":"10.1109/AERO.1994.291200","DOIUrl":"https://doi.org/10.1109/AERO.1994.291200","url":null,"abstract":"An aerospace vehicle may operate throughout a wide range of flight environmental conditions that affect its dynamic characteristics. Even when the control design incorporates a degree of robustness, system parameters may drift enough to cause its performance to degrade below an acceptable level. The object of this paper is to develop a change detection algorithm so that we can build a highly adaptive control system applicable to aircraft systems. The idea is to detect system changes with minimal time delay. The algorithm developed is called Minimal Time-Change Detection Algorithm (MT-CDA) which detects the instant of change as quickly as possible with false-alarm probability below a certain specified level. Simulation results for the aircraft lateral motion with a known or unknown change in control gain matrices, in the presence of doublet input, indicate that the algorithm works fairly well as theory indicates though there is a difficulty in deciding the exact amount of change in some situations. One of MT-CDA distinguishing properties is that detection delay of MT-CDA is superior to that of Whiteness Test.<<ETX>>","PeriodicalId":223269,"journal":{"name":"Proceedings of 1994 IEEE Aerospace Applications Conference Proceedings","volume":"426 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127605511","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}
{"title":"The risk of trust vs. the cost of assurance/spl minus/trades in the implementation of a secure LAN","authors":"K.J. Profet, C. Lavine, K. Meyer","doi":"10.1109/AERO.1994.291204","DOIUrl":"https://doi.org/10.1109/AERO.1994.291204","url":null,"abstract":"For more than a decade, private and public enterprises have realized increasing productivity benefits from the utilization of Local Area Network (LAN) technology. However, organizations required to provide high security for sensitive information were largely shut out of this general prosperity, since network products provided few security protections for the information they carried. Products showing increased attention to security prompted a new investigation into the feasibility of connecting standalone personal computers in a secure network. This paper is the result of that study. Beginning with a hypothetical problem, we develop alternative solutions for two different operating environments using network products available today. These are compared on the bases of security, cost, impact on current operations, ease of use, and future growth. The risks inherent in trusting people to comply with manual security procedures are compared with the costs of assuring that the LAN implements them automatically.<<ETX>>","PeriodicalId":223269,"journal":{"name":"Proceedings of 1994 IEEE Aerospace Applications Conference Proceedings","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133066983","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}
{"title":"Modular avionics and open systems architecture for future manned space flight","authors":"A. Anderman","doi":"10.1109/AERO.1994.291199","DOIUrl":"https://doi.org/10.1109/AERO.1994.291199","url":null,"abstract":"Alternative combinations of generic avionics modules for future manned space flight, such as in preliminary designs for the proposed NASA Advanced Manned Launch System/ Personnel Launch System (AMLS/PLS), are presented in this paper. The USAF Modular Avionics Systems Architecture (MASA) and the NASA/JSC \"Space Generic Open Avionics Architecture (SGOAA)\" standards are briefly described. Future manned space transportation will probably depend on a mix of vehicles, while anticipating continued use of the Shuttle Fleet through the first quarter of the 21st century. Proposed incremental avionics upgrade concepts to enable the Space Shuttle to operate to the year 2030, are also discussed.<<ETX>>","PeriodicalId":223269,"journal":{"name":"Proceedings of 1994 IEEE Aerospace Applications Conference Proceedings","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130641367","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}
{"title":"Three-dimensional SAR imaging technique for MMW seekers","authors":"B. Mahafza, D. Knight, N. Audeh","doi":"10.1109/AERO.1994.291196","DOIUrl":"https://doi.org/10.1109/AERO.1994.291196","url":null,"abstract":"This paper presents a new three-dimensional (3D) synthetic aperture radar (SAR) imaging technique which can be used for millimeter wave (MMW) seekers. It utilizes a linear array in transverse motion to synthesize a two-dimensional (2D) synthetic array. Elements of the linear array are fired sequentially (one element at a time), while all elements receive in parallel. A 2D information sequence is computed from the equiphase two-way signal returns. A new signal model based on a third-order Taylor series expansion about incremental relative time, azimuth, elevation and target height is used. Scatterers are detected as peaks in the amplitude spectrum of the information sequence. Detection is performed in two stages. First, all scatterers within a footprint are detected using an incomplete signal model where target height is set to zero. Then, processing using the complete signal model is performed only on range bins containing significant scatterer returns. The difference between the two images is used to measure target height. Computer simulation shows that this technique is accurate and almost impulse invariant. An example is used to demonstrate this approach.<<ETX>>","PeriodicalId":223269,"journal":{"name":"Proceedings of 1994 IEEE Aerospace Applications Conference Proceedings","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128980689","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}
{"title":"Description and results of a satellite laser communication/tracking simulation","authors":"G.S. Mecherle, K.L. Marrs","doi":"10.1109/AERO.1994.291201","DOIUrl":"https://doi.org/10.1109/AERO.1994.291201","url":null,"abstract":"A detailed simulation of a satellite laser communication crosslink was developed to evaluate expected communication performance and sensitivity to steady-state and transient pointing and tracking errors caused by satellite disturbances. The interrelated effects of communication and tracking are modeled within the simulation in a \"real time\" Monte Carlo fashion. An overview of this simulation is presented along with current simulation results. Comparison is made of simulation and hardware measurements, where available. Preliminary results indicate successful communication and tracking performance is possible during a satellite Delta-V thruster firing.<<ETX>>","PeriodicalId":223269,"journal":{"name":"Proceedings of 1994 IEEE Aerospace Applications Conference Proceedings","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125257657","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}
{"title":"TRMM VIRS: a design for low radiation space environments","authors":"D. Roberts, B. Peterson, B. Koseluk","doi":"10.1109/AERO.1994.291195","DOIUrl":"https://doi.org/10.1109/AERO.1994.291195","url":null,"abstract":"The Visual and Infrared Scanner (VIRS) is an instrument aboard the Tropical Rainfall Measuring Mission (TRMM) satellite. This instrument uses a paddle wheel mirror arrangement in conjunction with a Cassegrain telescope to obtain five bands of calibration and earth data. The acquisition, packetization, and transmission of the data is coordinated by one of two 1750 A-based processor boards. This processor and its associated flight software are also responsible for receiving commands, executing commands, and safing the instrument. The design of the VIRS processor hardware and flight software was driven by a number of the usual concerns over reliability and availability. However, one of the other major design drivers was the operating environment of the satellite. Since the VIRS is operating at an altitude of 350 kilometers, the environment is a fairly benign one with respect to radiation exposure. This paper describes the top-level operation and design of the VIRS instrument. The operation section summarizes the top-level operation of the instrument. The design section focuses on the hardware and software tradeoffs that were made with a low radiation environment in mind.<<ETX>>","PeriodicalId":223269,"journal":{"name":"Proceedings of 1994 IEEE Aerospace Applications Conference Proceedings","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128834629","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}
{"title":"Photonic systems for antenna applications","authors":"M. VanBlaricum","doi":"10.1109/AERO.1994.291190","DOIUrl":"https://doi.org/10.1109/AERO.1994.291190","url":null,"abstract":"For well over a decade, research groups around the world have been investigating photonic devices for use in antenna, phased array, and electromagnetic field sensor systems. Applications have included shipboard EMC monitoring, EMP measurements, anechoic chamber calibration, novel antenna and array designs, antenna remoting, and smart skins. Photonic antenna links allow immunity from electromagnetic interference, provide an extremely wide working bandwidth, and allow long cable runs with a minimum of loss. Recent developments in laser technology allow photonic-based links to have very low noise figure and high dynamic range. Optoelectronic devices are now being built in III-V semiconductors (GaAs, InP) and polymers which will ultimately lead to opto-electronic integration with MMIC devices. Photonic systems will revolutionize the way in which electromagnetic measurement and antenna systems will be designed and built in the future. This paper presents an overview to the different types of photonic links and modulator systems available to the antenna engineer.<<ETX>>","PeriodicalId":223269,"journal":{"name":"Proceedings of 1994 IEEE Aerospace Applications Conference Proceedings","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123823408","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}