Journal of the Institute of Navigation 2015 Spring

ljrlove2008

Journal of the Institute of Navigation. Volume 62, Number 1 (Spring 2015)

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GNSS Multipath Mitigation using Antenna Motion（1 - 22）见2楼

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Classification and Mathematical Expression of Different Interference Signals on a GPS Receiver（23 - 37）见3楼

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CSC Code Discriminator: Theoretical Analysis of Performance（39 - 54）见4楼

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Towards an Efficient, Intelligent, Opportunistic Smartphone Indoor Positioning System（55 - 72）见5楼

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Jamming Detection in GNSS Receivers: Performance Evaluation of Field Trials（73 - 82）见6楼

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Railway Track Irregularity Measuring by GNSS/INS Integration（83 - 93）见7楼

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ljrlove2008

Title: GNSS Multipath Mitigation using Antenna Motion
Author(s): Mark L. Psiaki, Tunc Ertan, Brady W. O'Hanlon, Steven P. Powell
Abstract: A method is developed for characterizing and compensating specular GNSS multipath by considering signal amplitude and phase variations in response to antenna motion. This method seeks to improve multipath rejection capabilities. A known antenna motion profile is combined with a batch filter to estimate the code phase, carrier phase, and amplitude of the direct signal, the relative code phase, carrier phase, carrier Doppler shift, and amplitude of each significant multipath component, and the directions of arrival of the direct and multipath components. Hardware signal simulator results indicate accurate estimation of all multipath features, and experimental test results demonstrate measurable improvements in estimates of carrier amplitude in all cases, of direct-path carrier-phase in many cases, and of direct-path code phase in some cases. Anomalous results have also been obtained, including specular multipath component estimates that occur in doublets and that may represent attempts by the batch filter to approximate diffuse multipath.

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ljrlove2008

Title: Classification and Mathematical Expression of Different Interference Signals on a GPS Receiver
Author(s): Mohammad K. Bek, Ehab M. Shaheen, Sherif A. Elgamel
Abstract: Interference is one of the major concerns in using the global positioning system (GPS) for civilian and military applications. In this paper, a new classification of different interference signals is presented. This classification is based on the interference signal’s bandwidth and the GPS correlator coherent integration time. The new classification simplifies the evaluation of the interference effect on the GPS receiver correlator output for different interference signals such as: continuous wave interference (CWI), narrowband interference (NBI), partial band interference (PBI), and broadband interference (BBI). Novel closed form analytical expressions for the GPS receiver correlator output power for CWI, NBI, PBI, and BBI are derived. The effect of the GPS correlator coherent integration time, the interference bandwidth, and the interference frequency error are also investigated under the impact of these types of interference.

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ljrlove2008

Title: CSC Code Discriminator: Theoretical Analysis of Performance
Author(s): Emanuela Falletti, Beatrice Motella, Micaela Troglia Gamba
Abstract: This paper presents the theoretical development and analysis of a novel DLL discriminator robust to multipath errors, called the Combination of Squared Correlators (CSC). The CSC discriminator features a simple implementation based on four (complex) static correlators per channel, without falling into the wide family of patented architectures. In this paper, the theoretical analysis of the properties of the CSC architecture is developed in a well structured context: (i) definition of the discrimination rule; (ii) theoretical analysis in the absence of noise; (iii) theoretical noise tracking jitter analysis; and, (iv) multipath error envelope analysis. In all cases, the CSC results are compared to those of the Strobe discriminator, which is the natural benchmark. The promising performance of the CSC discriminator inserted in a complete software receiver is also proved in a heavy multipath scenario, expressly simulated to stress the code tracking loop robustness.

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ljrlove2008

Title: Towards an Efficient, Intelligent, Opportunistic Smartphone Indoor Positioning System
Author(s): Ramsey M. Faragher, Robert K. Harle
Abstract: Many smartphone-based indoor tracking methods exist today, but to ensure consumer acceptance of such technologies, it is critical that these systems minimize their effect on the battery life of the device. Signal fingerprinting methods can provide good performance with low processing overhead but require prior surveying. Methods exploiting opportunistic sensing and machine learning techniques such as Simultaneous Localization and Mapping (SLAM) need no prior data but come at the cost of high computational load. This paper proposes a smartphone-based indoor positioning system that exploits a new intelligent filtering approach to reduce this computational load. ’SmartSLAM’ moves between different sensor fusion algorithms depending on the current level of certainty in the system, maintaining good positioning performance with low computational load, and improving battery life. This paper introduces two core algorithms underpinning SmartSLAM: the Fingerprint EKF (FEKF) and Fingerprint EKF Smoother (FEKFS).

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ljrlove2008

Title: Jamming Detection in GNSS Receivers: Performance Evaluation of Field Trials
Author(s): Erik Axell, Fredrik M. Eklöf, Peter Johansson, Mikael Alexandersson, Dennis M. Akos
Abstract: We evaluate the detection performance of several commercial interference detectors and of a detector that uses the automatic gain control (AGC) level as a test statistic. The evaluations are based on actual measurements of GPS signals and different types of jamming signals, and were performed at the Vidsel test range in northern Sweden. The AGC detector and the Chronos CTL-3500 were shown to work well for all types of jamming signals. The J-alert was able to detect a wideband (20 MHz) signal but not the narrow band (<2 MHz) signals. By contrast, the jamming indicator on a Ublox 6H receiver was only able to detect a slowly varying modulated CW signal, but not signals with larger bandwidth (>2 MHz). We confirmed that C/N0-based Android application detectors could work well in static scenarios but are not suitable in dynamic scenarios, since they cannot distinguish between decreased GPS signal strength and increased interference.

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ljrlove2008

Title: Railway Track Irregularity Measuring by GNSS/INS Integration
Author(s): Qijin Chen, Xiaoji Niu, Quan Zhang, Yahao Cheng
Abstract: Railway track irregularity measuring is a task of fundamental importance to guarantee operating safety and arrange proper maintenance, particularly for the high-speed lines. Conventional measuring methods cannot satisfy the requirements of accuracy and time-efficiency simultaneously. A GNSS/INS integrated technique is proposed based on the fact that railway track irregularity detection is essentially an issue of relative surveying. Key technologies of the integration algorithm aiming at track irregularity measuring are proposed to improve the performance of the GNSS/INS system. Results show that the proposed method can fulfill 1 mm relative accuracy in identifying track irregularities in the kinematic surveying mode, which means this method can satisfy the accuracy requirement for a high-speed line and is ten times faster than the conventional method based on total station.

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xileito

感谢，感谢

ryanclark

导航的东西不多啊，谢谢lz