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Tampere, Finland

Lilja J.,Nokia Inc. | Salonen P.,Nokia Inc. | Kaija T.,Patria Aviation Oy | De Maagt P.,European Space Agency
IEEE Transactions on Antennas and Propagation | Year: 2012

Antennas made out of textile materials suffer from performance perturbing effects whose impact mainly depend on the mechanical properties of the fabrics. The soft and flexible nature of the fabrics is essential for user comfort in wearable systems, but makes the antenna performance sensitive to bending, stretching, compression, and the manufacturing process. Furthermore, water absorption into the woven textile structures can increase both the permittivity and the dielectric loss of the substrate materials. The potential performance reduction due to the material characteristics is addressed in this paper, and methods to improve performance robustness are introduced. Tests show that the use of a textile cover provides a rugged design which is insensitive to the effects of abrasion, saline water and varying climatic conditions. A dual frequency textile antenna is thoroughly tested and shown to be fully compliant with Iridium and GPS specifications. © 2012 IEEE. Source


Lilja J.,Nokia Inc. | Pynttari V.,Nokia Inc. | Kaija T.,Patria Aviation Oy | Makinen R.,Tampere University of Technology | And 6 more authors.
IEEE Antennas and Propagation Magazine | Year: 2013

The Cospas (Cosmicheskaya Sistyema Poiska Avariynich Sudov)-Sarsat Search-and-Rescue (SAR) satellite system provides distress alert and location data to assist rescue operations at sea, in the air, or on land. This paper summarizes the design, development, and verification for a body-worn antenna system interfaced with commercial Cospas-Sarsat personal locator beacons (PLBs), where the implemented system is integrated within an inflatable live vest. The modular approach adopted in the work allows different antenna configurations for different platforms. The electrical and mechanical requirements for antenna materials and antennas were derived from the Cospas-Sarsat system requirements, possible antenna platforms, and the maritime operational environments. The antennas were used in field tests organized in cooperation with the local Cospas-Sarsat search-and-rescue authorities. The field tests were a success. In both cases, low-earth orbit search-and-rescue (LEOSAR) satellites detected the distress signal within minutes, and accurately resolved the location. An additional detection by Geostationary Orbit Search and Rescue (GEOSAR) satellite confirmed the successful operation of the body-worn antenna system. Source


Huovelin J.,University of Helsinki | Vainio R.,University of Helsinki | Andersson H.,Oxford Instruments | Valtonen E.,Aboa Space Research Oy | And 19 more authors.
Planetary and Space Science | Year: 2010

The Solar Intensity X-ray and particle Spectrometer (SIXS) on the BepiColombo Mercury Planetary Orbiter (MPO) will investigate the direct solar X-rays, and energetic protons and electrons which pass the Spacecraft on their way to the surface of Mercury. These measurements are vitally important for understanding quantitatively the processes that make Mercury's surface glow in X-rays, since all X-rays from Mercury are due to interactions of the surface with incoming highly energetic photons and space particles. The X-ray emission of Mercury's surface will be analysed to understand its structure and composition. SIXS data will also be utilised for studies of the solar X-ray corona, flares, solar energetic particles, and the magnetosphere of Mercury, and for providing information on solar eruptions to other BepiColombo instruments. SIXS consists of two detector subsystems. The X-ray detector system includes three identical GaAs PIN detectors which measure the solar spectrum at 1-20 keV energy range, and their combined field-of-view covers ∼1/4 of the whole sky. The particle detector system consists of an assembly including a cubic central CsI(Tl) scintillator detector with five of its six surfaces covered by a thin Si detector, which together perform low-resolution particle spectroscopy with a rough angular resolution over a field-of-view covering ∼1/4 of the whole sky. The energy range of detected particle spectra is 0.1-3 MeV for electrons and 1-30 MeV for protons. A major task for the SIXS instrument is the measurement of solar X-rays on the dayside of Mercury's surface to enable modeling of X-ray fluorescence and scattering on the planet's surface. Since highly energetic particles are expected to also induce a significant amount of X-ray emission via particle-induced X-ray emission (PIXE) and bremsstrahlung when they are absorbed by the solid surface of the planet Mercury, SIXS performs measurements of fluxes and spectra of protons and electrons. SIXS performs particle measurement at all orbital phases of the MPO as the particle radiation can occur also on the night side of Mercury. The energy ranges, resolutions, and timings of X-ray and particle measurements by SIXS have been adjusted to match with the requirements for interpretation of data from Mercury's surface, to be performed by utilising the data of the Mercury Imaging X-ray Spectrometer (MIXS), which will measure X-ray emission from the surface. © 2008 Elsevier Ltd. All rights reserved. Source


Fraser G.W.,University of Leicester | Carpenter J.D.,University of Leicester | Rothery D.A.,Open University Milton Keynes | Pearson J.F.,University of Leicester | And 49 more authors.
Planetary and Space Science | Year: 2010

The Mercury Imaging X-ray Spectrometer (MIXS) on the BepiColombo Mercury Planetary Orbiter (MPO) will measure fluorescent X-ray emission from the surface of Mercury in the energy range 0.5-7.5 keV, which is induced by incident solar X-rays and solar wind electrons and protons. These X-rays will reveal the elemental composition of the surface of Mercury and aid the determination of the planet's evolution. MIXS is a two component instrument. A collimated channel (MIXS-C) provides measurements on scales of 70-270 km, sufficient to separate the major Mercurian terrains. A second channel (MIXS-T) is the first imaging X-ray telescope for planetary remote sensing and will make measurements on spatial scales of less than 10 km for major elements during solar flares, sufficient to isolate surface landforms, such as craters and their internal structures. The spatial resolution achieved by MIXS-T is made possible by novel, low mass microchannel plate X-ray optics, in a Wolter type I optical geometry. MIXS measurements of surface elemental composition will help determine rock types, the evolution of the surface and ultimately a probable formation process for the planet. In this paper we present MIXS and its predicted performance at Mercury as well as discussing the role that MIXS measurements will play in answering the major questions about Mercury. © 2009 Elsevier Ltd. All rights reserved. Source


Kivikyto T.,Patria Aviation Oy | Laaksonen J.,Patria Aviation Oy
European Space Agency, (Special Publication) ESA SP | Year: 2014

PATRIA has implemented highly educated Remote Interface Units in various ESA missions. For the Sentinel-2 and EarthCARE it was constructed also to include Solar Array Drive Electronics. The same control design as for Solar Array Drive function was also piggybacked in Magneto Torque control drives and other mission specific stepper motor drives. The purpose of this paper is to summarise and present the PATRIA Solar Array Drive Electronics design advantages. Source

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