Lars Erling Bråten

• Williams, Lewis Raymond; Hjermann, Natanael Ferreira; Sagsveen, Bendik Andreas; Romeijer, Arthur; Hoel, Karina Vieira & Bråten, Lars Erling (2025). A Deployable Conical Log Spiral Antenna for Small Spacecraft: Mechanical Design and Test. Aerospace. 12(4). doi: 10.3390/aerospace12040326. Fulltekst i vitenarkiv
• Williams, Lewis Raymond; Hoel, Karina Vieira; Bråten, Lars Erling; Romeijer, Arthur; Hjermann, Natanael Ferreira & Sagsveen, Bendik Andreas (2025). A Deployable Conical Log Spiral Antenna for Small Spacecraft: Electronic Design and Test. Aerospace. 12(3). doi: 10.3390/aerospace12030218. Fulltekst i vitenarkiv
• Arneson, Vegard; Bråten, Lars Erling; Sander, Jostein; Mjelde, Terje Mikal Olsen & Olsen, Øystein (2017). Land-Mobile X-band Satellite Measuremensts in Norway, Experiment Description and First Results, 2017 11th European Conference on Antennas and Propagation (EUCAP), 19-24 March 2017. IEEE (Institute of Electrical and Electronics Engineers). ISSN 9781509037421. s. 2351–2355. doi: 10.23919/EuCAP.2017.7928368. Fulltekst i vitenarkiv
• Rytír, Martin; Cheffena, Michael; Grotthing, Per Arne; Bråten, Lars Erling & Tjelta, Terje (2017). Three-Site Diversity at Ka-Band Satellite Links in Norway: Gain, Fade Duration and the Impact of Switching Schemes. IEEE Transactions on Antennas and Propagation. ISSN 0018-926X. doi: 10.1109/TAP.2017.2751667. Fulltekst i vitenarkiv Vis sammendrag

  Analysis of two years of measurements from a three-site satellite beacon diversity experiment in Norway is presented. The operating frequency was 19.68 GHz, elevation angles were between 21.7° and 22°, and site separations 23, 29.7 and 50.1 km. Due to spatial decorrelation of rain, simultaneous attenuation at all sites occurs much less frequently than at a single site. All three two-site diversity combinations and a threesite diversity combination were investigated. Measured values for diversity gain at 0.01% exceedance level were 8.8, 10.7 and 12.1 dB for the two-site pairs and 12.5 dB for three-sites, given a single site attenuation level between 13 and 16 dB. Comparison of the measured data showed excellent agreement with current ITU-R model. Fade duration statistics for single-site and for the combinations are analyzed and it is shown that the statistics for the diversity combinations can be modelled using a double-lognormal function as is the case for single-site statistics. Analysis of the effects of a non-perfect switch-over scheme showed that using moderate switch-over threshold levels and time delays, the number of switch-overs can be significantly reduced while most of the diversity gain and reduction in number of fades is retained.

• Rytír, Martin & Bråten, Lars Erling (2016). Microdiversity on a 20 GHz slant path in Norway, 2016 10th European Conference on Antennas and Propagation (EuCAP 2016). IEEE (Institute of Electrical and Electronics Engineers). ISSN 9781509022342. s. 3599–3603. doi: 10.1109/EuCAP.2016.7481977. Fulltekst i vitenarkiv
• Bråten, Lars Erling; Rytír, Martin & Grotthing, Per Arne (2015). One year of 20 GHz satellite measurement data from a nordic maritime environment. I Caeiro, Luísa & Ferreira, Manuel (Red.), 2015 9th European Conference on Antennas and Propagation (EuCAP), Lisbon, 13-17 April 2015. IEEE (Institute of Electrical and Electronics Engineers). ISSN 9788890701856. Fulltekst i vitenarkiv
• Tjelta, Terje; Mamen, Jostein; Bråten, Lars Erling & Grotthing, Per Arne (2015). Measured and modeled spatial rain rate correlation to improve the prediction method for satellite site diversity. Radio Science. ISSN 0048-6604. doi: 10.1002/2014RS005476. Fulltekst i vitenarkiv Vis sammendrag

  Rainfall rate varies both temporarily and spatially. Radio systems, where rain attenuation causes outages, may take advantage of this effect to increase the radio link or satellite link availability using diversity techniques. In the Oslo region with Norwegian Meteorological Institute located at Blindern, there are 24 tipping bucket rain gauges within 50 km radius of the institute where each station has 5 years or more of simultaneous data periods with the station at the institute. The simultaneous data have been used to calculate spatial rain rate correlation and derive a prediction method based on separation distance and orientation with respect to dominating weather direction. Part of joint rain rate distribution was fitted to lognormal to find the measured correlation coefficients. In addition, an analysis of independent radiosonde data suggests that prevailing wind at 700 hPa or 850 hPa altitude (approximately 3000 m or 1500 m above sea level), conditioned thunderstorm index in the range of 15 to 20, may be used to identify the actual rainfall movement or dominant weather direction. Compared with current recommended method by the Radiocommunication Sector of International Telecommunication Union, the new method gives an improved site diversity prediction judged by site selection of minimum 20 GHz attenuation data measured in 2012 from Earth stations located at Nittedal and Kjeller separated by 23 km.

• Rytír, Martin & Bråten, Lars Erling (2014). Measurements of K-band scintillation on a low elevation satellite-Earth path in Norway. I Floury, Nicolas & Mangenot, Cyril (Red.), EuCAP 2014 - The 8th European Conference on Antennas and Propagation. IEEE (Institute of Electrical and Electronics Engineers). ISSN 9788890701849. doi: 10.1109/EuCAP.2014.6901803. Fulltekst i vitenarkiv Vis sammendrag

  The objective of this study is to characterise K-band (20 GHz) space-Earth propagation scintillation at Vadso, Norway. A literature study of scintillation impairments for communication via geostationary satellites has been carried out. An experiment designed for beacon measurements and 7 months of measurements are described and analysed. Scintillation is extracted from the data by highpass filtering. A 0.008 Hz filter cut-off frequency is identified by spectral analysis and analysis of the original time series. Diurnal variation of scintillation shows similar levels of variation compared with previously reported except for May and July where this variation is significantly reduced. The observed variations do not follow available cloud observation data well. Monthly and long term statistics of scintillation fading are compared with available models, with most models overpredicting the expected values. The differences are most significant in the month of April.

• Bråten, Lars Erling & Arneson, Vegard (2014). Measurements of single tree attenuation for vehicular satellite communications at X-band. I Floury, Nicolas & Mangenot, Cyril (Red.), EuCAP 2014 - The 8th European Conference on Antennas and Propagation. IEEE (Institute of Electrical and Electronics Engineers). ISSN 9788890701849. doi: 10.1109/eucap.2014.6902006. Fulltekst i vitenarkiv
• Urke, Andreas Ramstad; Bråten, Lars Erling & Øvsthus, Knut (2012). TCP challenges in hybrid military satellite networks; measurements and comparison. MILCOM IEEE Military Communications Conference. ISSN 2155-7578. doi: 10.1109/milcom.2012.6415561. Fulltekst i vitenarkiv
• Cheffena, Michael & Bråten, Lars Erling (2011). Low-Cost Digital Beacon Receiver Based on Software-Defined Radio. IEEE Antennas & Propagation Magazine. ISSN 1045-9243. 53(1), s. 50–55. doi: 10.1109/MAP.2011.5773567. Fulltekst i vitenarkiv
• Bråten, Lars Erling & Cheffena, Michael (2011). Low-Cost Digital Beacon Receiver Based on Software-Defined Radio. IEEE Antennas & Propagation Magazine. ISSN 1045-9243. 53(1), s. 50–55. doi: 10.1109/MAP.2011.5773567. Fulltekst i vitenarkiv
• Cheffena, Michael; Bråten, Lars Erling; Ekman, Torbjörn & Tjelta, Terje (2010). Combined Dynamic Channel Simulator for High Capacity Broadband Fixed Wireless Access Systems. IEEE Transactions on Antennas and Propagation. ISSN 0018-926X. 58(10), s. 3421–3426. doi: 10.1109/TAP.2010.2055784. Fulltekst i vitenarkiv Vis sammendrag

  We present a time dynamic channel simulator for broadband fixed wireless access systems which properly combines earlier reported models for single degradation effects. The wideband model combines the effect of rain, scintillation, vegetation and multipath propagation. The objective is to specify the relationship between propagation effects and combine them to construct a comprehensive channel model suitable for designing fade mitigation techniques and evaluating system performance. The dynamics of rain attenuation is done using the Maseng-Bakken model. The multipath propagation is modeled using the geometrical based single bounce elliptical channel model. The spatial correlation between multipath taps during rain is incorporated using a space-time rain attenuation model. A lowpass filter which models the power spectral density of scintillation is used to describe the dynamic characteristics of scintillation. The signal fading due to swaying vegetation is described by utilizing a multiple mass-spring system to represent a tree and a turbulent wind model. In addition, numerical results under different combinations of propagation impairments are presented.

• Voldhaug, Jan Erik; Bråten, Lars Erling & Sander, Jostein (2010). Deployable WiMAX in a Forest Area; Channel Measurements and Modelling. MILCOM IEEE Military Communications Conference. ISSN 2155-7578. s. 2400–2405. doi: 10.1109/MILCOM.2010.5680326. Fulltekst i vitenarkiv
• Cheffena, Michael; Bråten, Lars Erling & Ekman, Torbjörn (2009). On the Space-Time Variations of Rain Attenuation. IEEE Transactions on Antennas and Propagation. ISSN 0018-926X. 57(6), s. 1771–1782. doi: 10.1109/TAP.2009.2019862. Fulltekst i vitenarkiv
• Cheffena, Michael; Bråten, Lars Erling & Ekman, Torbjörn (2009). On the Space-Time Variations of Rain Attenuation. IEEE Transactions on Antennas and Propagation. ISSN 0018-926X. 57(6), s. 1771–1782. doi: 10.1109/TAP.2009.2019862. Fulltekst i vitenarkiv

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• Williams, Lewis Raymond; Bråten, Lars Erling; Hoel, Karina Vieira & Sagsveen, Bendik Andreas (2023). DESIGN AND TEST OF A DEPLOYABLE BROADBAND ANTENNA FOR LOW FREQUENCY SYNTHETIC APERTURE INTERFEROMETRIC RADIOMETRY FROM SMALL SATELLITES. Proceedings of the International Astronautical Congress. ISSN 0074-1795. Fulltekst i vitenarkiv
• Eriksen, Torkild; Bråten, Lars Erling; Skauen, Andreas Nordmo; Haugli, Hans Christian; Løge, Lars & Bjørnevik, Anders [Vis alle 8 forfattere av denne artikkelen] (2018). VDE-SAT – Preliminary verification results for proposed satellite component of new maritime communications system. Fulltekst i vitenarkiv
• Bråten, Lars Erling; Arneson, Vegard; Svenes, Knut Ragnar; Eriksen, Torkild & Olsen, Øystein (2018). Channel Modelling for VHF Data Exchange System via Satellite. Fulltekst i vitenarkiv
• Grythe, Knut Harald; Bråten, Lars Erling; Rønning, Snorre Stavik & Tjelta, Terje (2018). Predicting Near-Time Satellite Signal Attenuation at Ka-band Using Tropospheric Weather. doi: 10.1049/cp.2018.0617. Fulltekst i vitenarkiv Vis sammendrag

  There are satellite communication applications where it is desirable to predict near time (e.g. 2 to 12 h) propagation losses at Ka-band due to hydrometeor precipitation. We present results from a project investigating the possibility and quality of short term prediction of satellite link attenuation at Ka-band. The starting point is a 67 h near time numerical weather prediction data from the Norwegian Meteorological Institute. A period of 3 months and for 3 sites in Norway have been studied. Based upon these accumulated 9 months of data, the precipitation along the satellite link to the ground terminal is calculated for every hour. The attenuation results from the model is compared to high accuracy contemporary measurements of the same path. If the forecast is predicting the presence of precipitation correctly, the predicted attenuation error has a low bias and the standard deviation value is typically in the order of 1.5 dB

• Haugli, Hans Christian; Løge, Lars; Alagha, Nader Sheikholeslami; Bjørnevik, Anders; Storesund, Frode André & Christiansen, Stig Erik [Vis alle 8 forfattere av denne artikkelen] (2017). The VHF Data Exchange System (VDES) and Norsat-2 satellite testing. Fulltekst i vitenarkiv
• Arneson, Vegard; Bråten, Lars Erling; Sander, Jostein; Mjelde, Terje Mikal Olsen & Olsen, Øystein (2017). Land-Mobile X-band Satellite Measuremensts in Norway, Experiment Description and First Results. Fulltekst i vitenarkiv
• Tjelta, Terje; Rytír, Martin; Bråten, Lars Erling; Grotthing, Per Arne; Cheffena, Michael & Håkegård, Jan Erik (2017). Results of a Ka Band Campaign for the Characterisation of Propagation Conditions for SatCom Systems at High Latitudes. doi: 10.23919/EuCAP.2017.7928507. Fulltekst i vitenarkiv Vis sammendrag

  Satellite services in the High North are utilized extensively for both communication purposes and for earth and climate observations. This paper presents results of two year measurements at 20 GHz and co-sited meteorological data. The results suggest that with 7–8 dB margin, services can be provided with 99 % availability for systems with elevation angles as low as 3.2° and 3 dB for elevation angles above 10.1°. Measured attenuation distributions support International Telecommunication Union prediction methods within 3 to 4 dB for 99.99 % of the time. However, scintillation and multipath are not well predicted at the lowest elevation angle.

• Eriksen, Torkild; Bråten, Lars Erling; Haugli, Hans Christian & Storesund, Frode André (2016). VDE-SAT – A new maritime communications system. Fulltekst i vitenarkiv Vis sammendrag

  The VHF data exchange system (VDES), also referred to as the next generation of the Automatic Identification System (AIS), is under development. New frequency channels were allocated for the terrestrial component in the World Radiocommunication Conference in 2015, enabling higher data throughput and a variety of applications for the maritime community. For the satellite component (VDE-SAT), necessary to make VDES a global system, studies of the compliance with existing systems were requested by ITU. This paper presents the first VDE-SAT downlink campaign sponsored by the European Space Agency (ESA) as well as an overview of VDES and the regulatory provisions. The objective of the ESA test campaign is to evaluate the performance of the proposed downlink waveforms and demonstrate the service concept. The campaign will be carried out by Space Norway, Kongsberg Seatex and the Norwegian Defence Research Establishment (FFI) with a VDE-SAT test transponder on-board Norsat-2. The transmissions will be received by a vessel sailing in Arctic waters and studied in terms of symbol error rates and other performance figures that will be analysed as function of waveform, communications geometry, etc. The e-Navigation Maritime Service Portfolios of the International Maritime Organization (IMO), machine-to-machine communications, e-mail and commercial services would benefit from a VDE-SAT component. The communication needs addressed in the IMO Polar Code as well as the need for satellite communications on small vessels could be met.

• Rytír, Martin & Bråten, Lars Erling (2016). Microdiversity on a 20 GHz slant path in Norway. Fulltekst i vitenarkiv
• Rytír, Martin; Grotthing, Per Arne; Tjelta, Terje; Bråten, Lars Erling & Riva, Carlo (2015). Three-Site Diversity on Low-Elevation 20 GHz Links in Norway. Fulltekst i vitenarkiv
• Vanhoenacker-Janvier, Danielle; Bouchard, Pierre; Bråten, Lars Erling; Fabbro, Vincent; Kourogiorgas, Charilaos & Rogers, David (2013). Channel Models for Aeronautical and Low Elevation Radio Links. Fulltekst i vitenarkiv
• Bråten, Lars Erling; Sander, Jostein & Mjelde, Terje Mikal Olsen (2013). Satellite-Earth K-band Beacon Measurements at Kjeller, Norway. Fulltekst i vitenarkiv
• Bråten, Lars Erling; Sander, Jostein; Mjelde, Terje Mikal Olsen & Tjelta, Terje (2013). SITE DIVERSITY ON TWO SLANT PATH LINKS IN NORWAY. Fulltekst i vitenarkiv Vis sammendrag

  The objective of this study is to characterise the effect spatial selection diversity on two K-band space- Earth links. An experiment designed for measuring attenuation and precipitation, and one year of measurements are described. The 19.3 GHz beacon from the satellite Astra 4A was received simultaneously at the sites Kjeller and Eggemoen, Norway, separated by 48 km. The measured results at the two sites are used to characterise the achievable improvement when utilising two receive sites and switching diversity. The measured distribution of attenuation when utilising selection diversity is compared with single site attenuation, a significant obtainable diversity benefit is available. The one year measured selection diversity improvement is higher than predicted by ITU-R Rec. P.618-10 for small time percentages, corresponding to high availability requirements relevant for gateway stations. At Eggemoen, both measured rain intensity and attenuation exceed the predicted values for small time percentages.

• Urke, Andreas R.; Bråten, Lars Erling & Øvsthus, Knut (2012). TCP challenges in hybrid military satellite networks; measurements and comparison. Fulltekst i vitenarkiv
• Rosello, J.; Antonio, Martellucci; Acosta, Raul; Nessel, J.; Bråten, Lars Erling & Riva, Carlo (2012). 26-GHz data downlink for LEO satellites. Fulltekst i vitenarkiv
• Lemorton, Joël; Fabbro, Vincent; Kourogiorgas, Charilaos; Bouchard, Pierre; Rogers, Dave & Luini, Lorenzo [Vis alle 11 forfattere av denne artikkelen] (2011). Review of prediction methods for low-elevation aerospace systems and new achievements. Fulltekst i vitenarkiv
• Voldhaug, Jan Erik; Bråten, Lars Erling & Sander, Jostein (2010). Deployable WiMAX in a Forest Area; Channel Measurements and Modelling. Fulltekst i vitenarkiv Vis sammendrag

  The performance of vehicle mounted WiMAX equipment has been tested in a forest environment. Path attenuation was measured at 2.3 GHz with a bandwidth of 5 MHz during the summer season. With a base station sector antenna with adjustable mast height and an omni-directional vehicle antenna at 2 m height, the received signal strength was recorded in a number of stationary positions. The excess attenuation caused by the vegetation is found to be reasonably well modelled by the current ITU-R prediction method for one terminal in woodland. The maximum attenuation was extracted from the measurements to adjust the ITU-R model to the local environment and the four base station antenna heights employed. Only moderate variation in vegetation attenuation was observed between the base station antenna heights of 3.5, 5.5, and 10.5 m, while at 14 m height the attenuation was about 5 dB lower. Shadow attenuation in dB follows a Gaussian distribution reasonably well. The highest standard deviation was observed for transmit antenna height of 14 m, where it reached 8 dB. Thus, moderate improvement in signal strength was achieved by elevating the transmit antenna, with somewhat lower average path loss at the highest antenna position. When utilising 2nd order base station antenna diversity the lowest base station antenna height benefitted most from diversity. The downlink diversity gain observed is significantly less than in the uplink. The measurements indicate that a range of about 700 m can be achieved for this setup in this environment.

• Cheffena, Michael & Bråten, Lars Erling (2009). Low-cost digital beacon receiver base on software defined radio. Fulltekst i vitenarkiv
• Carrie, Guillaume; Lacoste, Frederic; Castanet, L.; Cheffena, Michael & Bråten, Lars Erling (2008). A robust estimator of the dynamic characteristics of rain attenuation - Application to time series synthesis for Ka-band and Q/V-band communication systems. Fulltekst i vitenarkiv
• Bråten, Lars Erling; Voldhaug, Jan Erik & Øvsthus, Knut (2008). Medium access for a military narrowband wireless ad-hoc network; requirements and initial approaches. Fulltekst i vitenarkiv
• Bråten, Lars Erling & Åsen, Walther (2000). PREDICTION OF TIME DYNAMIC RAIN ATTENUATION AT MILLIMETRE WAVELENGTHS. Fulltekst i vitenarkiv
• Bråten, Lars Erling & Tjelta, Terje (2013). Planned and early results of low elevation angle measurements at Ka-band from two projects in Norway. Forsvarets forskningsinstitutt . ISSN 9788246422336. Fulltekst i vitenarkiv Vis sammendrag

  Geostationary satellite fixed communication services for high latitude and mostly maritimeenvironment are increasingly important for Norway and the regions in the high north in general. Although measurement results have been reported from several earlier experiments there is still alack of satisfactory knowledge, particularly at Ka-band, both with respect to attenuation due to hydrometeor precipitation and to clear air scintillation and ducting effects. New measurementexperiments are being and have been set up to collect more data. This report presents twoinitiatives: the ESA project on Ka-band radio characterization for SatCom services in arctic andhigh latitude regions and early results from another project run by FFI and the NorwegianDefence. The two projects will in total take measurements from 7 locations. The measurementstations’ latitudes range from 57° to 78° N and cover both a maritime and in-land climates. Theprojects will run until the end of 2015.

• Bråten, Lars Erling; Bjugan, Vidar; Køien, Geir M.; Tardy, Isabella; Walter, Knut Erik & Worren, Tore Arthur [Vis alle 7 forfattere av denne artikkelen] (2007). UMTS capacity considerations and recommendations on capacity-increasing techniques. Telenor R&D. Fulltekst i vitenarkiv

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