{"title":"Low-cost GNSS sampler based on the beaglebone black SBC","authors":"D. Olesen, J. Jakobsen, P. Knudsen","doi":"10.1109/NAVITEC.2016.8060034","DOIUrl":"https://doi.org/10.1109/NAVITEC.2016.8060034","url":null,"abstract":"This paper describes the design of a simple low cost GNSS sampler with integrated storage. The sampler is built from low cost, off-the-shelf components. The proposed design stores digital IF samples from two separate front ends and record the data to a SD card for post-mission processing. The GNSS sampler currently supports GPS and GLONASS signals, but could also be configured for Galileo reception. The design is based on the popular low cost BeagleBone Black Single Board Computer (SBC) and two evaluation kits of the MAX2769 GNSS Radio Frequency (RF) front end. The design is based on two identical coprocessors in the processor of the BeagleBone, known as Programmable Realtime Units (PRU). The sampler has been designed for portability and data acqusition on small Unmanned Aerial Vehicles (UAVs).","PeriodicalId":228093,"journal":{"name":"2016 8th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117189153","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}
{"title":"An autonomous GNSS anti-spoofing technique","authors":"G. Caparra, C. Wullems, R. Ioannides","doi":"10.1109/NAVITEC.2016.7849355","DOIUrl":"https://doi.org/10.1109/NAVITEC.2016.7849355","url":null,"abstract":"In recent years, the problem of Position, Navigation and Timing (PNT) resiliency has received significant attention due to an increasing awareness on threats and the vulnerability of the current GNSS signals. Several proposed solutions make uses of cryptography to protect against spoofing. A limitation of cryptographic techniques is that they introduce a communication and processing computation overhead and may impact the performance in terms of availability and continuity for GNSS users. This paper introduces autonomous non cryptographic antispoofing mechanisms, that exploit semi-codeless receiver techniques to detect spoofing for signals with a component making use of spreading code encryption.","PeriodicalId":228093,"journal":{"name":"2016 8th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC)","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125562520","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}
David Gómez-Casco, E. Lohan, J. López-Salcedo, G. Seco-Granados
{"title":"Multilag frequency estimation for high-order BOC signals in the acquisition stage","authors":"David Gómez-Casco, E. Lohan, J. López-Salcedo, G. Seco-Granados","doi":"10.1109/NAVITEC.2016.7849325","DOIUrl":"https://doi.org/10.1109/NAVITEC.2016.7849325","url":null,"abstract":"In the context of global navigation satellite systems, this paper addresses the problem of refining the Doppler frequency estimation provided in the acquisition stage for highorder binary offset carrier (BOC) signals in post-correlation. The refinement of Doppler frequency must be done because the estimation obtained from the acquisition stage is not usually accurate enough to track the signal in the tracking stage. In this work, we only use the cross-ambiguity function (CAF) created in the acquisition stage to perform the refinement. A least squares estimator has been already applied to mitigate this problem. We propose a new technique, referred to as multilag least squares estimator, which improves the performance of the least squares estimator by exploiting the autocorrelation shape of high-order BOC signals. Moreover, the Cramer-Rao bound and the expected Cramer-Rao bound are derived as benchmark to compare the performance of the least squares and multilag least squares estimators.","PeriodicalId":228093,"journal":{"name":"2016 8th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127011451","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}
Niccolò Pastori, L. Siniscalco, A. Zin, A. Ferrario, A. Emmanuele
{"title":"Relief of computational burden for a robust carrier tracking based on a kalman filter implementation","authors":"Niccolò Pastori, L. Siniscalco, A. Zin, A. Ferrario, A. Emmanuele","doi":"10.1109/NAVITEC.2016.7849356","DOIUrl":"https://doi.org/10.1109/NAVITEC.2016.7849356","url":null,"abstract":"The aim of this paper is to investigate an innovative carrier tracking scheme capable of maintaining the robustness characteristics typical of the Kalman filter tracking loop architecture and, at the same time, reducing the computational load due to the burdensome operations needed by the legacy Kalman filter implementation. Computationally speaking, the heaviest stage of the Kalman filter scheme is represented by the correction step where several matrices multiplications and divisions are conducted. Novel ideas for a light Kalman filter tracking loop are proposed, tested on a software receiver simulator, compared with a standard Kalman filter architecture and with the reference phase locked loop scheme, especially in terms of accuracy performance and robustness against feared events, such as Cycle Slips and Loss of Locks, in harsh environments.","PeriodicalId":228093,"journal":{"name":"2016 8th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124912562","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}
S. Paternostro, T. Moore, C. Hill, J. Atkin, G. Maere, H. Morvan
{"title":"Examples of user algorithms implementing ARAIM techniques for integrity performance prediction, procedures development and pre-flight operations","authors":"S. Paternostro, T. Moore, C. Hill, J. Atkin, G. Maere, H. Morvan","doi":"10.1109/NAVITEC.2016.7849330","DOIUrl":"https://doi.org/10.1109/NAVITEC.2016.7849330","url":null,"abstract":"Advanced Receiver Autonomous Integrity Monitoring (ARAIM) is a new Aircraft Based Augmentation System (ABAS) technique, firstly presented in the two reports of the GNSS Evolutionary Architecture Study (GEAS). The ARAIM technique offers the opportunity to enable GNSS receivers to serve as a primary means of navigation, worldwide, for precision approach down to LPV-200 operation, while at the same time potentially reducing the support which has to be provided by Ground and Satellite Based Augmented Systems (GBAS and SBAS).","PeriodicalId":228093,"journal":{"name":"2016 8th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC)","volume":"155 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124337543","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}
S. Zorn, M. Niestroj, M. Meurer, Friederike Wendler, M. Cuntz
{"title":"Self-contained calibration determination by jointly solving the attitude estimation and calibration problem in the steering vector domain","authors":"S. Zorn, M. Niestroj, M. Meurer, Friederike Wendler, M. Cuntz","doi":"10.1109/NAVITEC.2016.7849321","DOIUrl":"https://doi.org/10.1109/NAVITEC.2016.7849321","url":null,"abstract":"Antenna calibration is a mandatory requirement to determine the attitude of a multi-antenna receiver. Moreover, knowing the antenna attitude can vastly improve detection and mitigation of spoofers and / or Radio Frequency Interferences (RFIs). In todays receivers the time-varying phase offset introduced by the active elements like amplifiers, downconverters as well as various filters and unequal cable lengths are usually calibrated using a pilot signal, which is injected in the antenna signal. This method, however, does not only complicate the manufacturing process, but also increases the complexity of the receiver architecture and power consumptions. New approaches developed recently use GNSS live signals for calibration. These methods are established based on the fact that for each incoming GNSS signal the direction of arrival (DOA) is exactly known by means of the ephemeris data, which is transmitted from each satellite. In order to estimate the calibration phases, the DOAs of the received satellite signals are compared with their corresponding expected DOAs, which are determined based on the ephemeris data. The problem, however, lies in the fact, that the expected DOAs are given in the East-North-Up (ENU) coordinate frame, whereas the measured DOAs are given in the local coordinate frame and are additionally affected by the unknown phase offsets to be calibrated. The proposed algorithm therefore solves the attitude estimation and calibration problem jointly. This paper proposes a novel algorithm and validates it using measurement data.","PeriodicalId":228093,"journal":{"name":"2016 8th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC)","volume":"77 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122544451","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}
{"title":"Positioning performance of chip-scale atomic clock GNSS augmentation systems","authors":"D. Calero, E. Fernández, M. E. Parés","doi":"10.1109/NAVITEC.2016.7849326","DOIUrl":"https://doi.org/10.1109/NAVITEC.2016.7849326","url":null,"abstract":"Current GNSS (Global Navigation Satellite System) receivers include an internal quartz oscillator, such as TCXO (Temperature Compensated Crystal Oscillator) or similar, limited by its frequency stability and a poor accuracy, being one of the main sources of uncertainty in the navigation solution (also multipath and ionosphere effects are an important error sources.) Replacing the internal TCXO clock of GNSS receivers by a higher frequency stability clock such a CSAC (Chip Scale Atomic Clock) can improve the navigation solution in terms of availability, positioning accuracy, tracking recovery, multipath and jamming mitigation and spoofing attacks detection. For achieving these benefits, the deterministic errors from the CSAC need to be modelled, by determining and predicting the clock frequency stability in the positioning estimation process. The procedure of calculating a position without the need of estimating continually the clock error parameter is also known as clock coasting. The presented research shows the potential of the clock coasting method in order to be able to obtain position with only three satellites, improve the vertical positioning accuracy and increase the navigation solution availability.","PeriodicalId":228093,"journal":{"name":"2016 8th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC)","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115100330","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}
M. Bartolucci, J. A. del Peral-Rosado, Roger Estatuet-Castillo, J. García-Molina, M. Crisci, G. Corazza
{"title":"Synchronisation of low-cost open source SDRS for navigation applications","authors":"M. Bartolucci, J. A. del Peral-Rosado, Roger Estatuet-Castillo, J. García-Molina, M. Crisci, G. Corazza","doi":"10.1109/NAVITEC.2016.7849328","DOIUrl":"https://doi.org/10.1109/NAVITEC.2016.7849328","url":null,"abstract":"This paper describes a new method for the synchronisation of multiple low-cost open source software-defined radios (SDR). This solution enables the use of low-cost SDRs in interesting navigation applications, such as hybrid positioning algorithms, interference localisation, and cooperative positioning among others. Time synchronisation is achieved thanks to a time pulse that can be generated either by one of the SDRs or by an external source, such as a GNSS receiver providing 1PPS signal. Experimental results show that the proposed method effectively reduces the synchronisation offset between multiple SDRs, to less than one sampling period.","PeriodicalId":228093,"journal":{"name":"2016 8th 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":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125131096","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}
{"title":"Performance of a VDFLL GNSS receiver architecture in presence of interference","authors":"Fernando M. G. Sousa, F. Nunes","doi":"10.1109/NAVITEC.2016.7849329","DOIUrl":"https://doi.org/10.1109/NAVITEC.2016.7849329","url":null,"abstract":"We discuss the advantages of using a vector delay/frequency-locked loop (VDFLL) architecture for GNSS receivers operating in scenarios disturbed by radio-frequency interference. Narrowband (sinusoidal) and wideband (chirp) interference signals are considered in the analysis. The VDFLL is constituted by a bank of code and frequency discriminators feeding a central extended Kalman filter that estimates the receiver’s position, velocity, and clock bias. Simulation results are obtained using sine-phase binary offset carrier BOCs(1,1) modulation. The results are compared with the theoretical performance determined by the effective signal power to noise density ratio.","PeriodicalId":228093,"journal":{"name":"2016 8th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126460065","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}
{"title":"Performance of a scintillation robust vector tracking for gnss carrier phase signals","authors":"Jose M. V. Marcal, F. Nunes","doi":"10.1109/ICL-GNSS.2016.7533841","DOIUrl":"https://doi.org/10.1109/ICL-GNSS.2016.7533841","url":null,"abstract":"An implementation of a robust vector phase-locked loop (VPLL) for joint tracking of carrier phase from the navigation satellites in the event of ionospheric scintillation is presented. This partitioned tracking method leads to an increased tolerance to ionospheric disturbances due to scintillation in the carrier phase tracking, providing a trade off between the pure VPLL and the classic scalar tracking loops. This method also allows for smoother transitions by using a weighted combination of scalar and vector tracking operation modes, which can be of importance when the environmental variables change and the state estimation may not cope with the fast changing dynamics, leading to harsh transitions and possibly to phase lock loss or inaccurate results.","PeriodicalId":228093,"journal":{"name":"2016 8th 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":"2016-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129600843","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}