Search query: muti  peak detection in  acquring gps

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abstract: Power consumption of Global Positioning System (GPS) acquisition is a great challenge for energy constrained applications. In this work, a metric named acquisition mean computation overhead is proposed to measure the energy cost. A novel multi peak double dwell (MP/DD) acquisition method for GPS weak signal is proposed. It adopts multi peak correlation results as candidates in the first acquisition dwell and selects the largest one as the final acquisition result in the second acquisition dwell. Theoretical analysis and numerical simulation are presented in detail. Meanwhile, the very large scale integration (VLSI) implementation of coarse and fine grained acquisition engines applied to the proposed method is done. The detection probability and acquisition mean computation overhead are simulated using the Monte Carlo method, and its mean acquisition power is tested with an actual chip. We fabricated the GPS signal acquisition engine with a 40 nm complementary metal oxide semiconductor (CMOS) process. The simulation results demonstrate that detection probability is promoted from 18% to 67% when signal power is equal to 23 dB/Hz. The acquisition mean computation overhead is reduced greatly by 64% Measurement results show that the energy consumption of this design is only 21.5% of the conventional double dwell/maximum (DD/MAX) method.
author_names: Zhen Wang

Hengfeng Zhang

Min Wang

Xinning Liu

Y Zhuang

Hao Cai

Jun Yang

Longxing Shi
title: Multi Peak Double Dwell GPS Weak Signal Acquisition Method and VLSI Implementation for Energy Constrained Applications
year: 2018

abstract: This article proposes a global navigation satellite system (GNSS) spoofing detection and classification technique for single antenna receivers. We formulate an optimization problem at the baseband correlator domain by using the Least Absolute Shrinkage and Selection Operator (LASSO) We model correlator tap outputs of the received signal to form a dictionary of triangle shaped functions and leverage sparse signal processing to choose a decomposition of shifted matching triangles from said dictionary. The optimal solution of this minimization problem discriminates the presence of a potential spoofing attack peak by observing a decomposition of two different code phase values (authentic and spoofed) in a sparse vector output. We use a threshold to mitigate false alarms. Furthermore, we present a variation of the minimization problem by enhancing the dictionary to a higher resolution of shifted triangles. The proposed technique can be implemented as an advanced fine acquisition monitoring tool to aid in the tracking loops for spoofing mitigation. In our experiments, we are able to distinguish authentic and spoofer peaks from synthetic data simulations and from a real dataset, namely, the Texas spoofing test battery. The proposed method achieves 0.3% detection error rate for a spoofer attack in nominal signal to noise ratio conditions and an authentic over spoofer power of 3 dB.
author_names: Erick Schmidt

Nikolaos Gatsis

David Akopian
title: A GPS Spoofing Detection and Classification Correlator Based Technique Using the LASSO
venue: IEEE Transactions on Aerospace and Electronic Systems
year: 2020

abstract: Through the growing usage of Global Positioning System (GPS) for civilian applications, healthcare of the system has special importance. However, according to the characteristics of the GPS signals, there is a possibility of interferences on GPS signals. Among all distorting factors, spoofing is more deceitful, because the civil receiver is not able to distinguish the counterfeit signal from the genuine signal. In recent years, many efforts have been made to deal with spoofing. We studied recognition of the clear certainty of a spoofed condition in this work, which focuses on Signal Quality Monitoring (SQM) method. In an effort to troubleshoot the previous metrics and methods, we have introduced a new metric for interference detection that investigate both of in phase and quadrature components of correlation outputs also use parameters associated with the main peak in proper form. As a consequence of simultaneous evaluation of phase and amplitude of GPS signal, the proposed metric is more reliable and average of detection accuracy has increased from 1.3 (related to previous metrics) to 4.8.
author_names: A Farhadi

M Moazedi

Mohammad Reza Mosavi

Ali Sadr
title: A Novel Ratio Phase Metric of Signal Quality Monitoring for Real Time Detection of GPS Interference
venue: Wirel. Pers. Commun.
year: 2017

abstract: Due to the low received power, the signals of global positioning system (GPS) are too sensitive to intentional and unintentional radio frequency interference (RFI) Many safety applications relayed on GPS shall be protected from RFI, and interference detection and localization become an important technique to keep them work validly. However, Weak RFI is usually hampered by in band GPS signals which cause undesired correlation peaks when Time Difference of Arrival (TDOA) and other interference detections are applied. The RFI detection performance gets even worse with GPS multipath signals received. In this paper, a subspace projection method is proposed to remove GPS signals. Unlike existing methods, the projection subspace here is directly constructed by the signature waveform (SW) estimation of GPS signals, and it brings a great improvement on weak interference detection in GPS multipath environment. Simulation results show that the proposed method could mitigate GPS signals effectively in multipath environment, and it also improves the probability of interference detection with low jammer to noise ratio (JNR)
author_names: Xi Hong

Ning Chang

Wenjie Wang

Qinye Yin
title: Weak Interference Detection Improvement in GPS Multipath Environment
venue: 2018 14th IEEE International Conference on Signal Processing (ICSP)
year: 2018

abstract: In the presence of spoofing signal the GPS signal having the same PRN with the spoofer is hard to be acquired since the power of spoofing signal is usually stronger than that of GPS signal. If a spoofing signal exists for the same PRN, there are double peaks in two dimensional space of frequency and code phase in acquisition stage. Using double peak information it is possible to detect spoofing signal and acquire GPS information through separate channel tracking. In this paper we introduce an anti spoofing method using double peak detection, and thus can acquire GPS navigation data after two channel tracking for the same PRN as the spoofing signal.
author_names: Keum-Cheol Kwon

Cheol-Kwan Yang

Duk-Sun Shim
title: Anti Spoofing Method Using Double Peak Detection in the Two Dimensional C/A Code Search Space
year: 2013

abstract: Abstract Traffic peak period detection is one key issue in ITS research area, which can afford time information for traffic flow guidance. Classical methods devote themselves to detect the peak period of road segmentations and small road network areas. Namely, these methods focus on traffic peak period detection in small space scale. However, the traffic peak periods of road segmentations and small road network areas cannot present the traffic peak periods of the whole city. In fact, the traffic peak periods of the whole city are more important for the traffic administration department. To solve this problem, a new method for detecting traffic peak periods of the whole city is proposed, which is based on the traffic index cloud maps. Experimental results on the GPS data show that the proposed method can recognize the traffic peak periods in a large space scale accurately.
author_names: Yuni Li

Jianli Xiao
title: Traffic peak period detection using traffic index cloud maps
year: 2020

abstract: This work proposes a novel sparsity based decomposition method for the correlator output signals in GPS receivers capable of detecting spoofing attacks. We model complex correlator outputs of the received signal to form a dictionary of triangle shaped replicas and employ a sparsity technique that selects potential matching triangle replicas from said dictionary. We formulate an optimization problem at the receiver correlator domain by using the Least Absolute Shrinkage and Selection Operator (LASSO) to find sparse code phase peaks where such triangle shaped delays are located. The optimal solution of this optimization technique discriminates two different code phase values as authentic and spoofed peaks in a sparse vector output. We use a threshold to mitigate false alarms. Additionally, we present an expansion of the model by enhancing the dictionary to a collection of shifted triangles with higher resolution. Our experiments are able to discriminate authentic and spoofer peaks from synthetic GPS like simulations. We also test our method on a real dataset, namely the Texas Spoofing Test Battery (TEXBAT) Our method achieves less than 1% detection error rate (DER) in nominal signal to noise ratio (SNR) conditions.
author_names: Erick Schmidt

Nikolaos Gatsis

David Akopian
title: High Resolution Correlator Based Detection of GPS Spoofing Attacks Using the LASSO
venue: 2020 IEEE/ION Position, Location and Navigation Symposium (PLANS)
year: 2020

abstract: BackgroundA GPS/acoustic (GPS/A) geodetic observation technique allows us to determine far offshore plate motion in order to understand the mechanism of megathrust earthquakes. In this technique, the distance between a sea surface platform and seafloor transponders is estimated using the two way traveltimes (TWT) of acoustic signals. TWTs are determined by maximizing the cross correlation coefficient between the transmitted and returned signals. However, this analysis caused significantly wrong detection of TWT when the correlogram has an enlarged secondary envelope due to the enlarged amplitude of multiple signals depending on the relative spatial geometry between the ship and the transponder. The handled manual rereading of thousands of correlograms to obtain correct TWTs needs enormous time, and human errors may cause. To prevent these difficulties, an automated TWT determination procedure is valid to process numerous GPS/A data efficiently not only without human errors but also with high precision.Proposed methodsWe developed automated methods for precisely analyzing GPS/A data. Method 1: The maximum peak in the observed correlogram is read, and a synthetic correlogram is then subtracted from the observation. Then, the same operation is applied to the subtracted waveform. This procedure is iterated until the correlation coefficient lowers than a pre defined threshold. A true traveltime is defined as the fastest traveltime during the iterations. Method 2: The observed correlograms are divided into several groups based on their similarity through cluster analysis, and a master waveform in each group is selected. Then, the traveltime residual between the maximum and true peaks in the master waveform is manually evaluated. The obtained residual is employed as the correction value for each slave waveform. Further, we employed a seismic data projection to visually inspect the reliability of obtained results.ResultsWe confirmed that both new methods accurately correct misreadings in the current method, which amount to 0.4 0.8 ms roughly corresponding to 30 60 cm difference in the slant range.ConclusionsThus, the proposed algorithms significantly improve the estimation of the transponder location. Further analyses are required to determine the arbitrary threshold values and to construct fully automated algorithms.
author_names: Ryosuke Azuma

Fumiaki Tomita

Takeshi Iinuma

M Kido

Ryota Hino
title: Development and examination of new algorithms of traveltime detection in GPS/acoustic geodetic data for precise and automated analysis
venue: Earth, Planets and Space
year: 2016

abstract: Spoofing that emulates authentic signals to coerce target receivers into false navigation solutions is a severe threat to many applications based on Global Positioning System (GPS) In order to forge a reasonable navigation solution, a spoofer generally has to mimic signals of several GPS satellites simultaneously. In view of the fact that GPS signals originated from a single transmitter would essentially experience an identical wireless channel to a receiver, a GPS spoofing detection scheme is proposed based on comparing the multipath signature of received signals. More specifically, the delay and gain ratio between multiple paths of a wireless channel that cannot be masked by spoofing signals are exploited. The delays between the strongest and other correlation peaks associated with each satellite are first evaluated. A correlation peak with the same delay for different satellites and closest to the strongest peak is then selected and its ratio to the strongest peak is calculated. With an identical wireless channel, the ratios corresponding to different satellites would be highly correlated. In contrast, ratios of authentic satellite signals that experience independent channels would be independent of each other. GPS spoofing can therefore be detected. The proposed design has been validated by simulations.
author_names: Hao Li

Xianbin Wang
title: Detection of GPS spoofing through signal multipath signature analysis
venue: 2016 IEEE Canadian Conference on Electrical and Computer Engineering (CCECE)
year: 2016

abstract: The development of a technique for GPS acoustic (GPS/A) geodetic observations has enabled us to understand the slip distribution of the 2011 Tohoku oki earthquake. However, there remains an issue with the precision of GPS/A measurement is still lower by two orders of magnitude than that of on land GPS measurement due to problems in observations and data processing methods. In this study, we focus on the problem for determination of traveltimes of acoustic signals obtained from GPS/A measurement. The conventional approach for determining the two way traveltime of observed acoustic signals is to determine the maximum peak of the cross correlation waveforms between the transmitted and returned signals. However, the maximum peak often differs from the true peak due to the distortion in the correlation waveform which depends on the relative spatial geometry of the ship and station. These misread traveltimes have been re read manually so far. Such procedure is no longer applicable for processing vast array of data obtained at newly installed over 20 GPS/A stations after the 2011 Tohoku oki earthquake. The aim of this study is to develop fully automated algorithms for analyzing GPS/A data with high precision. We introduce here two algorithms. 1) We read the maximum peak in the observed correlogram and then deconvolve it by the synthetic correlogram. Then, we apply the same operation to the deconvolved waveform. This procedure is iterated until the correlation coefficient decreases lower than a pre defined threshold. A true traveltime is defined as the fastest traveltime during the iterations. 2) We classify the observed correlograms into several groups based on their similarity through cluster analyses and choose a master waveform in each group. Then evaluate the traveltime residual between the maximum peak and the true peak in the observed correlogram. Thus obtained residual is applied as the correction value of each clustered group. We also use a seismic data analysis tool to visually inspect whether above algorithms work properly. We confirmed that the both new methods properly correct for misreadings in the current method, which sometimes amount to several hundred micro seconds. This corresponds roughly to a 0.3 m difference in the slant range. Therefore, with the new algorithms, significant improvement in the estimation of the station location is expected. However, both methods have to be assigned an arbitrary value as a threshold. Further analyses are needed to determine arbitrary threshold values and to construct fully automated algorithms.
author_names: Ryosuke Azuma

Fumiaki Tomita

Takeshi Iinuma

Ryota Hino

M Kido

Hiromi Fujimoto

Yukihito Osada

Yusaku Ohta

Ikuko Wada
title: Development and examination of new methods for traveltime detection in GPS/A geodetic data to high precise and automatic
year: 2014