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Study on performance of IF GALILEO/GPS receivers synchronization

ZHU Ya-feng,TIAN Zeng-shan,ZHOU Yong-sheng,

重庆邮电大学学报(自然科学版) , 2008,
Abstract: 本文针对GALILEO/GPS中频接收机同步跟踪性能问题进行研究。主要进行GPS扩频信号和GALILEO BOC(m,n)信号的自相关函数峰值的比较,GPS/GALILEO接收机码跟踪、载波跟踪的速率精度的比较,其中码跟踪采取了延迟锁相环(DLL),载波跟踪采用costas锁相环。从仿真的结果可以看出,扩频码自相关函数具有单峰值,而BOS(m,n)信号自相关函数具有多峰值的特点,GALILEO接收机具有锁相速度快、精度高的特点。
On the Impact of Channel Cross-Correlations in High-Sensitivity Receivers for Galileo E1 OS and GPS L1C Signals  [PDF]
Davide Margaria,Beatrice Motella,Fabio Dovis
International Journal of Navigation and Observation , 2012, DOI: 10.1155/2012/132078
Abstract: One of the most promising features of the modernized global navigation satellite systems signals is the presence of pilot channels that, being data-transition free, allow for increasing the coherent integration time of the receivers. Generally speaking, the increased integration time allows to better average the thermal noise component, thus improving the postcorrelation SNR of the receiver in the acquisition phase. On the other hand, for a standalone receiver which is not aided or assisted, the acquisition architecture requires that only the pilot channel is processed, at least during the first steps of the procedure. The aim of this paper is to present a detailed investigation on the impact of the code cross-correlation properties in the reception of Galileo E1 Open Service and GPS L1C civil signals. Analytical and simulation results demonstrate that the S-curve of the code synchronization loop can be affected by a bias around the lock point. This effect depends on the code cross-correlation properties and on the receiver setup. Furthermore, in these cases, the sensitivity of the receiver to other error sources might increase, and the paper shows how in presence of an interfering signal the pseudorange bias can be magnified and lead to relevant performance degradation. 1. Introduction In the context of Global Navigation Satellite Systems (GNSS) receivers, the interest on the new modulations that will be used for the modernized GPS L1C and Galileo E1 Open Service (OS) civil signals grew rapidly in past years. The definition of new signals structure results from an agreement between the European Commission and Unites States of America. A common Multiplexed Binary Offset Carrier Modulation (MBOC) signal baseline has been adopted, with the aim of assuring the compatibility and interoperability between GPS and Galileo systems [1]. For the GPS L1C signal, USA has chosen the Time Multiplexed BOC (TMBOC) solution that multiplexes a BOC(1,1) with a BOC(6,1) in time domain [2], while the composite BOC (CBOC) is the implementation selected for the Galileo E1 OS Signal In Space (SIS) [3]. One of the main features of the modernized civil and open access signals is the presence of the pilot channels. Pilot channel has been introduced to allow the receivers to perform coherent integration over a long time, without facing the issue of unpredictable data transitions. As a consequence, the receiver is able to acquire satellite signals at lower SNR than the nominal value. In order to deal with such a need in current GPS receiver, assistance data have been defined and
Lámpsakos , 2010,
Abstract: Biografía de Galileo
Combined Constellations GPS and Galileo Systems
Jacek Januszewski
Artificial Satellites , 2006, DOI: 10.2478/v10018-007-0007-3
Abstract: As for the users of satellite navigation systems the actual slogan is GPS and Galileo the advantages and disadvantages of different combined constellations of these systems must be taken into account. The distributions (in per cent) of the numbers of satellites visible by the observer at different latitudes situated in open and restricted (urban canyon) area for different masking elevation angles (Hmin) for two combined constellations GPS + Galileo systems (I - 29 GPS satellites + 27 Galileo satellites, II - 29 GPS + 30 Galileo) are presented in this paper. In addition to it the detailed distributions for the observer at latitudes 50-60o for other constellations & elevation angles are demonstrated. For the first constellation the difference between the number of GPS satellites visible by the observer above horizon (Hmin = 0o) at latitudes 50-60o and the number of Galileo satellites visible by the same observer at the same time can be equal each number between plus 7 and minus 7. This fact must be taken into account in the production and the determination of the number of channel of GPS-Galileo integrated receivers.
Black Holes, Bandwidths and Beethoven  [PDF]
A. Kempf
Physics , 1999, DOI: 10.1063/1.533244
Abstract: It is usually believed that a function whose Fourier spectrum is bounded can vary at most as fast as its highest frequency component. This is in fact not the case, as Aharonov, Berry and others drastically demonstrated with explicit counter examples, so-called superoscillations. It has been claimed that even the recording of an entire Beethoven symphony can occur as part of a signal with 1Hz bandwidth. Bandlimited functions also occur as ultraviolet regularized fields. Their superoscillations have been suggested, for example, to resolve the transplanckian frequencies problem of black hole radiation. Here, we give an exact proof for generic superoscillations. Namely, we show that for every fixed bandwidth there exist functions which pass through any finite number of arbitrarily prespecified points. Further, we show that, in spite of the presence of superoscillations, the behavior of bandlimited functions can be characterized reliably, namely through an uncertainty relation. This also generalizes to time-varying bandwidths. In QFT, we identify the bandwidth as the in general spatially variable finite local density of degrees of freedom of ultraviolet regularized fields.
О. Сушич,?. Приходько
Proceedings of National Aviation University , 2011,
Abstract: The concept of integrity assessment of European satellite navigation system Galileo from a position of user requirements of global systems CNS/ATM is observed. Main factors which can lead to integrity risk are analysed, and experimental results of modeling integrity risk with use of the modern navigating equipment and original software are obtained Наведено метод оц нки ц л сност вропейсько супутниково нав гац йно системиGalileо. Розглянуто експериментальн результати моделювання ризику втрати ц л сност Galileo.The analysis of integrity assessment method of European satellite navigation system Galileo andexperimental results of Galileo integrity risk modeling are presented.Приведен метод оценки целостности Европейской спутниковой навигационной системыGalileo. Рассмотрены экспериментальные результаты моделирования риска потерицелостности Galileo. Розглянуто концепц ю оц нки ц л сност вропейсько супутниково нав гац йно системиGalileo з позиц потреб споживача глобальних систем CNS/ATM. Проанал зовано основн фактори, що можуть привести до ризику втрати ц л сност . Отримано експериментальн ре-зультати моделювання ризику втрати ц л сност з застосуванням сучасного нав гац йногообладнання та ориг нального програмного забезпечення
Javier Galeano,,Juan Manuel Pastor,Ildefonso Ruiz-Tapiador,GEOMEDIA
Revista Eureka sobre Ense?anza y Divulgación de las Ciencias , 2009,
Luz y sombra de Galileo Galilei
álvarez García, J.L.;
Revista mexicana de física E , 2009,
Abstract: beyond the various formal images about galileo galilei that exist, in this paper i present an image focused on his character and personality, which may allow to explain some important facts of the great italian scientist's life. galileo's relationship with kepler and the firs reactions of the italian academics, after his discoveries with the telescope are analyzed with some detail.
?Quién era Galileo?
Marquina, J.E.;álvarez, J.L.;
Revista mexicana de física E , 2009,
Abstract: galileo's life and scientific work, has been discussed and analyzed from many points of view. in this paper, the opinions of several authors are presented in order to show their profound divergences, as much in the philosophical as in the historical fields, that galileo provokes.
On Reasoning with Ambiguities  [PDF]
Uwe Reyle
Computer Science , 1995,
Abstract: The paper adresses the problem of reasoning with ambiguities. Semantic representations are presented that leave scope relations between quantifiers and/or other operators unspecified. Truth conditions are provided for these representations and different consequence relations are judged on the basis of intuitive correctness. Finally inference patterns are presented that operate directly on these underspecified structures, i.e. do not rely on any translation into the set of their disambiguations.

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