1,338 research outputs found

    Investigation of advanced navigation and guidance system concepts for all-weather rotorcraft operations

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    Results are presented of a survey conducted of active helicopter operators to determine the extent to which they wish to operate in IMC conditions, the visibility limits under which they would operate, the revenue benefits to be gained, and the percent of aircraft cost they would pay for such increased capability. Candidate systems were examined for capability to meet the requirements of a mission model constructed to represent the modes of flight normally encountered in low visibility conditions. Recommendations are made for development of high resolution radar, simulation of the control display system for steep approaches, and for development of an obstacle sensing system for detecting wires. A cost feasibility analysis is included

    Continued study of NAVSTAR/GPS for general aviation

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    A conceptual approach for examining the full potential of Global Positioning Systems (GPS) for the general aviation community is presented. Aspects of an experimental program to demonstrate these concepts are discussed. The report concludes with the observation that the true potential of GPS can only be exploited by utilization in concert with a data link. The capability afforded by the combination of position location and reporting stimulates the concept of GPS providing the auxiliary functions of collision avoidance, and approach and landing guidance. A series of general recommendations for future NASA and civil community efforts in order to continue to support GPS for general aviation are included

    Navigation and guidance requirements for commercial VTOL operations

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    The NASA Langley Research Center (LaRC) has undertaken a research program to develop the navigation, guidance, control, and flight management technology base needed by Government and industry in establishing systems design concepts and operating procedures for VTOL short-haul transportation systems in the 1980s time period. The VALT (VTOL Automatic Landing Technology) Program encompasses the investigation of operating systems and piloting techniques associated with VTOL operations under all-weather conditions from downtown vertiports; the definition of terminal air traffic and airspace requirements; and the development of avionics including navigation, guidance, controls, and displays for automated takeoff, cruise, and landing operations. The program includes requirements analyses, design studies, systems development, ground simulation, and flight validation efforts

    Use of Navigation Beacons to Support Lunar Vehicle Operations

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    To support a wide variety of lunar missions in a condensed regime, solutions are needed outside of the use of Earth-based orbit determination. This research presents an alternate approach to in-situ navigation through the use of beacons, similar to that used on Earth as well as under technology development efforts. An overview of the current state of navigation aids included as well as discussion of the Lunar Node 1 payload being built at NASA/Marshall Space Flight Center. Expected navigation results of this beacon payload for planned operation from the lunar surface are provided. Applications of navigation beacons to multiple stages of the proposed human lunar landing architecture are given, with initial analysis showing performance gains from the use of this technology. This work provides a starting point for continued analysis and design, laying out the foundation of how navigation beacons can be incorporated into the architecture to enable continued analysis, design, and future expanded capability

    Identification of high-level functional/system requirements for future civil transports

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    In order to accommodate the rapid growth in commercial aviation throughout the remainder of this century, the Federal Aviation Administration (FAA) is faced with a formidable challenge to upgrade and/or modernize the National Airspace System (NAS) without compromising safety or efficiency. A recurring theme in both the Aviation System Capital Investment Plan (CIP), which has replaced the NAS Plan, and the new FAA Plan for Research, Engineering, and Development (RE&D) rely on the application of new technologies and a greater use of automation. Identifying the high-level functional and system impacts of such modernization efforts on future civil transport operational requirements, particularly in terms of cockpit functionality and information transfer, was the primary objective of this project. The FAA planning documents for the NAS of the 2005 era and beyond were surveyed; major aircraft functional capabilities and system components required for such an operating environment were identified. A hierarchical structured analysis of the information processing and flows emanating from such functional/system components were conducted and the results documented in graphical form depicting the relationships between functions and systems

    Conceptual development of a ground-based radio-beacon navigation system for use on the surface of the moon

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    A spread-spectrum radio-beacon navigation system for use on the lunar surface is described. The subjects discussed are principle of operation and specifications to include power requirements, operating frequencies, weight, size, and range

    Automated tracking of the Florida manatee (Trichechus manatus)

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    The electronic, physical, biological and environmental factors involved in the automated remote tracking of the Florida manatee (Trichechus manatus) are identified. The current status of the manatee as an endangered species is provided. Brief descriptions of existing tracking and position locating systems are presented to identify the state of the art in these fields. An analysis of energy media is conducted to identify those with the highest probability of success for this application. Logistic questions such as the means of attachment and position of any equipment to be placed on the manatee are also investigated. Power sources and manateeborne electronics encapsulation techniques are studied and the results of a compter generated DF network analysis are summarized

    Timing subsystem development: Network synchronization experiments

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    This paper describes a program in which several experimental timing subsystem prototypes were designed, fabricated, and field tested using a small network of troposcatter and microwave digital communication links. This equipment was responsible for modem/radio interfacing, time interval measurement, clock adjustment and distribution, synchronization technique, and node to node information exchange. Presented are discussions of the design approach, measurement plan, and performance assessment methods. Recommendations are made based on the findings of the test program and an evaluation of the design of both the hardware and software elements of the timing subsystem prototypes

    Aerial applications dispersal systems control requirements study

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    Performance deficiencies in aerial liquid and dry dispersal systems are identified. Five control system concepts are explored: (1) end of field on/off control; (2) manual control of particle size and application rate from the aircraft; (3) manual control of deposit rate on the field; (4) automatic alarm and shut-off control; and (5) fully automatic control. Operational aspects of the concepts and specifications for improved control configurations are discussed in detail. A research plan to provide the technology needed to develop the proposed improvements is presented along with a flight program to verify the benefits achieved

    A Portuguese Case Study

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    There is a high national dependency on Position, Navigation and Timing (PNT) Systems for several individuals, services and organisations that depend on this information on a daily basis. Those who rely on precise, accurate and continuous information need to have resilient systems in order to be highly efficient and reliable. A resilient structure and constantly available systems makes it easier to predict a threat or rapidly recover in a hazardous environment. One of these organisations is the Portuguese Navy, whose main purposes are to combat and maintain maritime safety. In combat, resilient PNT systems are needed for providing robustness in case of any threat or even a simple occasional system failure. In order to guarantee maritime safety, for example in Search and Rescue Missions, the need of PNT information is constant and indispensable for positioning control. The large diversity of PNT-dependent equipment, developed over the last two decades, is a valid showcase for the high GPS dependency that is seen nowadays – which is vulnerable to various factors like interference, jamming, spoofing and ionospheric conditions. The recent interest over integrated PNT system resolutions is related to the search for redundancy, accuracy, precision, availability, low cost, coverage, reliability and continuity. This study aimed to build a current PNT Portuguese picture based on Stakeholder Analysis and Interviews; assess the vulnerability of those who depend mainly on GPS for PNT information and, find out what the next steps should be in order to create a National PNT Strategy.Existe uma elevada dependência nacional em sistemas de Posição, Navegação e Tempo (PNT) por parte de diversos indivíduos, serviços e organizações que dependem desta informação no seu dia-a-dia. Todos os que dependem de informação precisa, exata e contínua, necessitam de ter sistemas resilientes para que sejam altamente eficientes e fiáveis. Uma estrutura resiliente e sistemas continuamente disponíveis facilitam a previsão de possíveis ameaças ou a expedita recuperação da funcionalidade, em ambientes hostis. Uma destas organizações é a Marinha Portuguesa cujas funções principais são o combate, a salvaguarda da vida humana no mar e a segurança marítima e da navegação. Para o combate, são necessários sistemas PNT, resilientes, que ofereçam robustez em caso de uma simples ameaça ou falha temporária dos sistemas. Por forma a ser possível cumprir a missão, a necessidade de ter informação PNT, fidedigna e atualizada, é constante e indispensável para o controlo preciso e exato da posição. Uma unidade naval, por forma a permanecer continuamente no mar, manter a sua prontidão, treinar a sua guarnição ou ser empenhada num cenário de guerra, necessita de saber, com confiança e sem erros, a sua posição e referência de tempo. A grande diversidade de sistemas dependentes de informação PNT, desenvolveu-se em larga escala nas últimas duas décadas e sustenta cada vez mais a alta dependência do GPS, que é vulnerável a diversas fontes de erro, tais como interferência, empastelamento, mistificação e condições ionosféricas. Atualmente, o elevado interesse na criação de sistemas PNT integrados está associado à procura da redundância, exatidão, precisão, disponibilidade, baixo custo, cobertura, fiabilidade e continuidade. Este estudo teve como objetivos construir o panorama atual, em Portugal, ao nível dos Sistemas PNT, baseando-se numa análise de Stakeholders e entrevistas; avaliar a vulnerabilidade de organizações e serviços que dependam exclusivamente do GPS como fonte de informação PNT; e propor um possível caminho para que seja possível criar uma Estratégia PNT Naciona
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