641 research outputs found

    Real-time Aerial Magnetic and Vision-aided Navigation

    Get PDF
    Aerial magnetic navigation has shown to be a viable alternative navigation method that has the potential for world-wide availability, to include over oceans. Obtaining GPS-level accuracy using magnetic navigation alone is challenging, but magnetic navigation can be combined with other alternative navigation methods that are more posed to obtaining GPS-level accuracy in their current state. This research presents an aerial navigation solution combining magnetic navigation and vision-aided navigation to aid an inertial navigation system (INS). The navigation solution was demonstrated in real-time playback using simulated magnetic field measurements and flight-test captured visual imagery. Additionally, the navigation solution was flight-tested on a USAF F-16 to demonstrate magnetic navigation in the challenging magnetic environment seen on operationally representative dynamic platforms

    Aerial Simultaneous Localization and Mapping Using Earth\u27s Magnetic Anomaly Field

    Get PDF
    Aerial magnetic navigation has been shown to be a viable GPS-alternative, but requires a prior-surveyed magnetic map. The miniaturization of atomic magnetometers extends their application to small aircraft at low altitudes where magnetic maps are especially inaccurate or unavailable. This research presents a simultaneous localization and mapping (SLAM) approach to constrain the drift of an inertial navigation system (INS) without the need for a magnetic map. The filter was demonstrated using real measurements on a professional survey flight, and on an AFIT unmanned aerial vehicle

    A magnetometer based payload for a PTOL UAV with application in geophysical surveys

    Get PDF
    Includes bibliographical references.Applying the principles of physics to studying the Earth has given rise to the field of geophysics, which has been recognised as a separate discipline since the 19th century. The practical implementation of this field has led to a separate branch, aptly named exploration geophysics. Exploration geophysics aims to measure various naturally occurring phenomena associated with the Earth in order to make predictions about what might lie beneath the Earth’s surface. One of the fundamental phenomena associated with the Earth is the magnetic field or geomagnetic field. By localising magnetic anomalies within the geomagnetic field one can make predictions or inferences about the localised geophysical makeup and potential ore bodies, hydrocarbon deposits or archaeological artefacts that might exist below the surface. The fundamental sensor used to perform these surveys is the magnetometer. The concept of an unmanned aerial vehicle (UAV) has been around since 1915, with the first manufactured UAV appearing in 1916. Subsequent to the realisation of the UAV in the 1950s by Ryan Aeronautical for military reconnaissance, the idea of using UAV platforms to perform dull, dirty and dangerous functions has become common-place in the military environment. The first practical use of a UAV came in the 1991 Gulf War. The subsequent appearance of UAVs in the civilian realm can largely be attributed to the advent of low cost, high power density, lithium based batteries in the 1990s and the growth of the radio controlled (RC) hobbyist market

    Types and Characteristics of Data for Geomagnetic Field Modeling

    Get PDF
    Given here is material submitted at a symposium convened on Friday, August 23, 1991, at the General Assembly of the International Union of Geodesy and Geophysics (IUGG) held in Vienna, Austria. Models of the geomagnetic field are only as good as the data upon which they are based, and depend upon correct understanding of data characteristics such as accuracy, correlations, systematic errors, and general statistical properties. This symposium was intended to expose and illuminate these data characteristics

    NASA Geodynamics Program

    Get PDF
    Activities and achievements for the period of May 1983 to May 1984 for the NASA geodynamics program are summarized. Abstracts of papers presented at the Conference are inlcuded. Current publications associated with the NASA Geodynamics Program are listed

    Earth Resources: A continuing bibliography with indexes, Issue 35

    Get PDF
    This bibliography list 587 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System between July 1, and September 30, 1982. Emphasis is placed on the use of remote sensing and geophysical instrumentation in spacecraft and aircraft to survey and inventory natural resources and urban areas. Subject matter is grouped according to agriculture and forestry, environmental changes and cultural resources, geodesy and cartography, geology and mineral resources, hydrology and water management, data processing and distribution systems, instrumentation and sensors, and economic analysis

    NASA geodynamics program: Bibliography

    Get PDF
    The Seventh Geodynamics Program report summarizes program activities and achievements during 1988 and 1989. Included is a 115 page bibliography of the publications associated with the NASA Geodynamics Program since its initiation in 1979

    Magnetic sensors and gradiometers for detection of objects

    Get PDF
    Disertační práce popisuje vývoj nových detekčních zařízení s anizotropními magnetorezistoryThis thesis describes development of innovative sensor systems based on anisotropi
    • …
    corecore