2014 7th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC)最新文献

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On site validation in GNSS stations for multipath and interference mitigation structure (IMLP) 多径干扰减缓结构(IMLP)在GNSS站点的现场验证

2014 7th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC) Pub Date : 2014-12-01 DOI: 10.1109/NAVITEC.2014.7045137

A. Dessantis, L. Dicecca, L. D'Agristina, V. Crinó, P. Gabellini, P. Russo, F. A. Fernández, Antonio Castro, A. Quiles, R. Weiler

{"title":"On site validation in GNSS stations for multipath and interference mitigation structure (IMLP)","authors":"A. Dessantis, L. Dicecca, L. D'Agristina, V. Crinó, P. Gabellini, P. Russo, F. A. Fernández, Antonio Castro, A. Quiles, R. Weiler","doi":"10.1109/NAVITEC.2014.7045137","DOIUrl":"https://doi.org/10.1109/NAVITEC.2014.7045137","url":null,"abstract":"The mitigation of Interference and Multipath is of paramount importance for the GNSS reference stations since they potentially introduce significant errors on the measurements provided by these stations. The solution that has been used up to now in order to reduce the effect of multipath consists of using a small choke-ring ground plane, but unfortunately this solution results to be effective only to a very limited extent. The solution proposed in this paper, named \"Interference and Multipath Protector\" (IMLP), consists instead of adding an external structure able to deterministically change the antenna coverage. The general - effect of the IMLP structure is: - to reduce the unwanted gain at low elevation angles; - to leave the original pattern as much as possible unchanged for the high elevation angles. The paper summarizes recent simulation analyses and measurements results deriving from the study (design and development) of the IMLP structure solution.","PeriodicalId":254397,"journal":{"name":"2014 7th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128701556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Improving the availability of the SAR/Galileo return link service via network coding 通过网络编码提高SAR/伽利略返回链路服务的可用性

2014 7th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC) Pub Date : 2014-12-01 DOI: 10.1109/NAVITEC.2014.7045149

R. Alegre-Godoy, I. Stojkovic

{"title":"Improving the availability of the SAR/Galileo return link service via network coding","authors":"R. Alegre-Godoy, I. Stojkovic","doi":"10.1109/NAVITEC.2014.7045149","DOIUrl":"https://doi.org/10.1109/NAVITEC.2014.7045149","url":null,"abstract":"In this paper we investigate how to improve the availability (deliverability) of the Return Link Service (RLS) of the Search and Rescue service of Galileo (SAR/Galileo). More specifically, we focus on improving the probability that the emergency beacon receives the Return Link Message (RLM) sent in the I/NAV signal. It is wellknown that beacons in distress events may be in unpredictable and arbitrary position and particular surrounding conditions such as harsh weather (heavy rain) or suffer blocking (tilted ships, crashed aircraft, big waves, etc.). Hence, it is possible that some of the 4/8 SAR RLM frames which form the short/long RLM, sent by two satellites, are lost. In this paper we propose two solutions, which could be considered for the next generation of GALILEO, to improve the chances of obtaining the RLM even when the beacon loses some frames from both satellites. Our proposals take advantage of the spatial diversity inherent in the SAR/Galileo system. The first solution implies increasing and changing the bits of the I/NAV signal which signal the SAR RLM frames. The second solution also implies increasing and changing these bits and uses Network Coding (NC). Issues such as backward compatibility with the current system and complexity are also assessed in the paper.","PeriodicalId":254397,"journal":{"name":"2014 7th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129084681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Unambiguous tracking of high-order BOC signals in urban environments: Channel considerations 城市环境中高阶BOC信号的明确跟踪:信道考虑

2014 7th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC) Pub Date : 2014-12-01 DOI: 10.1109/NAVITEC.2014.7045147

J. García-Molina, M. Navarro-Gallardo†, G. López-Risueño, M. Crisci

{"title":"Unambiguous tracking of high-order BOC signals in urban environments: Channel considerations","authors":"J. García-Molina, M. Navarro-Gallardo†, G. López-Risueño, M. Crisci","doi":"10.1109/NAVITEC.2014.7045147","DOIUrl":"https://doi.org/10.1109/NAVITEC.2014.7045147","url":null,"abstract":"The usage of BOC modulations in GNSS provides a better code tracking accuracy than BPSK modulation at the cost of new correlation peaks appearing in the autocorrelation function. For high-order BOC modulations side peaks might be only few meters away from the main correlation peak to be tracked, so there is a risk to lock into one of those peaks, inducing therefore a bias in the pseudorange estimation. The probability of false lock can be in particular important in harsh channel conditions, where the unambiguous tracking can be difficult due to the low C/No and the presence of multipath, which impact can be relevant during fading periods. This paper presents typical channel conditions that should be considered in the design and assessment of unambiguous tracking techniques of high-order BOC signals, focusing in urban environments where the receiver might need to track the signal even at low C/No. A preliminary assessment of some state-of-the-art techniques in urban environments is presented, showing the limitations of some of the techniques, which have been designed considering very mild propagation conditions typically present in open sky environments. The multi-correlator approach is then presented as a possible way to overcome the limitations of techniques based on legacy GNSS receiver architectures. In this case the unambiguous tracking problem is presented as the minimization of a non-linear Least Squares cost function subject to restrictions and some design alternatives are discussed.","PeriodicalId":254397,"journal":{"name":"2014 7th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121612035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

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