scholarly journals GPS Swept Anti-Jamming Technique Based on Fast Orthogonal Search (FOS)

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3706
Author(s):  
Mohamed Tamazin ◽  
Michael J. Korenberg ◽  
Haidy Elghamrawy ◽  
Aboelmagd Noureldin
Keyword(s):  
Spectral Analysis ◽  
Spectral Estimation ◽  
Simulation System ◽  
Controlled Environment ◽  
Gps Receiver ◽  
Positioning Accuracy ◽  
Gps Receivers ◽  
Noise Floor ◽  
Fast Orthogonal Search ◽  
New Applications

Recently, there has been growing demand for GPS-based reliable positioning, with the broadening of a range of new applications that mainly rely on GPS. GPS receivers have, recently, been attractive targets for jamming. GPS signals are received below the noise floor. Thus, they are vulnerable to interference and jamming. A jamming signal can potentially decrease the SNR, which results in disruption of GPS-based services. This paper aims to propose a reliable and accurate, swept anti-jamming technique based on high-resolution spectral analysis, utilizing the FOS method to provide an accurate spectral estimation of the GPS swept jamming signal. resulting in suppressing the jamming signal efficiently at the signal processing stages in the GPS receiver. Experiments in this research are conducted using the SpirentTM GSS6700 simulation system to create a fully controlled environment to test and validate the developed method’s performance. The results demonstrated the proposed method’s capabilities to detect, estimate, and adequately suppress the GPS swept jamming signals. After the proposed anti-jamming module was employed, the software receiver was able to provide a continuous positioning solution during the presence of jamming within a 10 m positioning accuracy.

A new multipath channel estimation and mitigation using annihilation filter combined tracking loop implementation in software GPS receivers

2021 ◽  
Author(s):  
ARUL ELANGO ◽  
René Jr Landry
Keyword(s):  
Phase Error ◽  
Sampling Rate ◽  
Frequency Component ◽  
Gps Tracking ◽  
Gps Receiver ◽  
Tracking Loop ◽  
Positioning Accuracy ◽  
Gps Receivers ◽  
The Mean ◽  
Carrier Phase Error

Abstract Abstract: The multipath effect causes severe degradation in the positioning of commercial GPS receivers. Due to multipath error, the positioning accuracy could reach a few 10 meters. If the cumulative Multipath delay is less than 0.1-0.35 chips, then it is difficult to mitigate in GPS receivers. This causes severe degradation in GPS signals and can cause a measurement bias. To alleviate this problem, the estimation of multipath parameters using annihilating filter and its mitigation in the GPS tracking loop is proposed in this work. The estimation of randomly generated multipath signals can be performed in the receiver with a lower sampling rate when compared to the larger bandwidth of the GPS baseband signal. Here, the frequency components of the Multipath signal in superimposed complex exponentials have been transformed from the time delay and the amplitude of the path observables. The Rayleigh fading model in the urban scenario has been simulated in which the amplitude and the phase of the number of paths (i.e., the frequency component of superimposed complex exponentials) are set and this fading signal is convolved with GPS signal that forms the multipath faded signal. In the GPS receiver post-processing stage, with the help of the annihilation filter, the multipath components are estimated, then an inverse/adaptive filter and compensation technique are further applied to mitigate the multipath component. The mean square error with the different number of paths with noisy environments is analyzed utilizing the cadzaw denoising algorithm. The simulation results of the proposed technique employed in the tracking module of the software GPS receiver under severe multipath conditions indicate a substantial enhancement in the performance of the GPS receiver with minimal code and carrier phase error when compared to the least squares and adaptive blind equalization channel techniques. Moreover, the positioning accuracy is also calculated with the inclusion of multipath components in two satellites out of six satellites used in the simulation, the results showed that the annihilation filter improved the mean position accuracy up to 9.3023 meters.

scholarly journals Investigating the Benefits of Vector-Based GNSS Receivers for Autonomous Vehicles under Challenging Navigation Environments

Signals ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 121-137
Author(s):  
Haidy Y. F. Elghamrawy ◽  
Mohamed Tamazin ◽  
Aboelmagd Noureldin
Keyword(s):  
Autonomous Vehicles ◽  
Tracking System ◽  
Satellite System ◽  
Velocity Estimation ◽  
Estimation Accuracy ◽  
Positioning Accuracy ◽  
Gps Receivers ◽  
Car Industry ◽  
Vector Tracking ◽  
Global Navigation Satellite

There is a growing demand for robust and accurate positioning information for various applications, including the self-driving car industry. Such applications rely mainly on the Global Navigation Satellite System (GNSS), including the Global Positioning System (GPS). However, GPS positioning accuracy relies on several factors, such as satellite geometry, receiver architecture, and navigation environment, to name a few. In urban canyons in which there is a significant probability of signal blockage of one or more satellites and/or interference, the positioning accuracy of scalar-based GPS receivers drastically deteriorates. On the other hand, vector-based GPS receivers exhibit some immunity to momentary outages and interference. Therefore, it is becoming necessary to consider vector-based GPS receivers for several applications, especially safety-critical applications, including next-generation navigation technologies for autonomous vehicles. This paper investigates a vector-based receiver’s performance and compares it to its scalar counterpart in signal degraded conditions. The realistic simulation experiments in this paper are conducted on GPS L1 C/A signals generated using the SpirentTM simulation system to create a fully controlled environment to examine and validate the performance. The results show that the vector tracking system outperforms the scalar tracking in terms of position and velocity estimation accuracy in signal-degraded environments.

scholarly journals Impulse Noise: Can Hitting a Softball Harm Your Hearing?

2014 ◽  
Vol 2014 ◽  
pp. 1-4
Author(s):  
Korrine Cook ◽  
Samuel R. Atcherson
Keyword(s):  
Spectral Analysis ◽  
Frequency Response ◽  
Sound Pressure Level ◽  
Impulse Noise ◽  
Sound Pressure ◽  
Pressure Level ◽  
Noise Floor ◽  
Playing Field ◽  
Multiple Exposures ◽  
Amplitude Frequency Response

The purpose of this study is to identify whether or not different materials of softball bats (wooden, aluminum, and composite) are a potential risk harm to hearing when batting players strike a 12′′ core .40 softball during slow, underhand pitch typical of recreational games. Peak sound pressure level measurements and spectral analyses were conducted for three controlled softball pitches to a batting participant using each of the different bat materials in an unused outdoor playing field with regulation distances between the pitcher’s mound and batter’s box. The results revealed that highest recorded peak sound pressure level was recorded from the aluminum (124.6 dBC) bat followed by the composite (121.2 dBC) and wooden (120.0 dBC) bats. Spectral analysis revealed composite and wooden bats with similar broadly distributed amplitude-frequency response. The aluminum bat also produced a broadly distributed amplitude-frequency response, but there were also two very distinct peaks at around 1700 Hz and 2260 Hz above the noise floor that produced its ringing (or ping) sound after being struck. Impulse (transient) sounds less than 140 dBC may permit multiple exposures, and softball bats used in a recreational slow pitch may pose little to no risk to hearing.

Resolving the Issues of Capon and APES Approach for Projecting Enhanced Spectral Estimation

2016 ◽  
Vol 6 (2) ◽  
pp. 725
Author(s):  
Kantipudi MVV Prasad ◽  
H.N. Suresh
Keyword(s):  
Signal Processing ◽  
Spectral Analysis ◽  
Spectral Density ◽  
Power Spectral Density ◽  
Simple Technique ◽  
Spectral Estimation ◽  
Research Work ◽  
Research Community ◽  
The Past ◽  
Power Spectral

There are various applications on signal processing that is highly dependent on preciseness and accuracy of the outcomes in spectrum of signals. Hence, from the past two decades the research community has recognized the benefits, significance, as well as associated problems in carrying out a model for spectral estimation. While in-depth investigation of the existing literatures shows that there are various attempts by the researchers to solve the issues associated with spectral estimations, where majority of teh research work is inclined towards addressing problems associated with Capon and APES techniques of spectral analysis. Therefore, this paper introduces a very simple technique towards resolving the issues of Capon and APES techniques. The outcome of the study was analyzed using correlational factor and power spectral density to find the proposed system offers better spectral estimations compared to existing system.

scholarly journals Direction of Arrival Estimation of GPS Narrowband Jammers Using High-Resolution Techniques

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5532 ◽  
Author(s):  
Mohamed Moussa ◽  
Abdalla Osman ◽  
Mohamed Tamazin ◽  
Michael J. Korenberg ◽  
Aboelmagd Noureldin
Keyword(s):  
Linear Array ◽  
Classical Method ◽  
Spatial Separation ◽  
Direction Of Arrival ◽  
Doa Estimation ◽  
Circular Array ◽  
Gps Receivers ◽  
Fast Orthogonal Search ◽  
Jamming Detection ◽  
Ultimate Objective

GPS jamming is a considerable threat to applications that rely on GPS position, velocity, and time. Jamming detection is the first step in the mitigation process. The direction of arrival (DOA) estimation of jamming signals is affected by resolution. In the presence of multiple jamming sources whose spatial separation is very narrow, an incorrect number of jammers can be detected. Consequently, mitigation will be affected. The ultimate objective of this research is to enhance GPS receivers’ anti-jamming abilities. This research proposes an enhancement to the anti-jamming detection ability of GPS receivers that are equipped with a uniform linear array (ULA) and uniform circular array (UCA). The proposed array processing method utilizes fast orthogonal search (FOS) to target the accurate detection of the DOA of both single and multiple in-band CW jammers. Its performance is compared to the classical method and MUSIC. GPS signals obtained from a Spirent GSS6700 simulator and CW jamming signals were used. The proposed method produces a threefold advantage, higher accuracy DOA estimates, amplitudes, and a correct number of jammers. Therefore, the anti-jamming process can be significantly improved by limiting the erroneous spatial attenuation of GPS signals arriving from an angle close to the jammer.

Analysis of flowrates as a basis for the simulation of dry-running rotational positive displacement pumps

2002 ◽  
Vol 216 (12) ◽  
pp. 1197-1205 ◽  
Author(s):  
K Kauder ◽  
D Wenderott
Keyword(s):  
Mass Flow ◽  
Characteristic Number ◽  
Operational Reliability ◽  
Simulation System ◽  
Positive Displacement ◽  
Market Situation ◽  
Flow Through ◽  
The One ◽  
New Applications ◽  
Operational Behaviour

New applications improve the market situation of dry-running positive displacement pumps. The mostly empirically based design of these pumps has to take into account partly competing viewpoints. These viewpoints are energetic process optimization, on the one hand, and operational reliability, on the other hand. A simulation system can be used to solve this problem. The simulation system uses an energy and a mass balance in order to simulate the operational behaviour of the vacuum pumps. Therefore knowledge of the different states of flow through clearances in a vacuum is essential. The experimental examination of the flow is done by flood curve measurements, to describe the mass flow integrally using the characteristic number of the standardized mass flow. The results for some possible plain clearance shapes are discussed.

The Impact on the Positioning Accuracy of the Frequency Reference of a GPS Receiver

2012 ◽  
Vol 34 (1) ◽  
pp. 73-87 ◽  
Author(s):  
Ta-Kang Yeh ◽  
Chieh-Hung Chen ◽  
Guochang Xu ◽  
Chuan-Sheng Wang ◽  
Kwo-Hwa Chen
Keyword(s):  
Gps Receiver ◽  
Positioning Accuracy ◽  
Frequency Reference ◽  
The Impact

Determination of global positioning system (GPS) receiver clock errors: impact on positioning accuracy

2009 ◽  
Vol 20 (7) ◽  
pp. 075105 ◽  
Author(s):  
Ta-Kang Yeh ◽  
Cheinway Hwang ◽  
Guochang Xu ◽  
Chuan-Sheng Wang ◽  
Chien-Chih Lee
Keyword(s):  
Global Positioning System ◽  
Positioning System ◽  
Gps Receiver ◽  
Positioning Accuracy ◽  
Global Positioning ◽  
Receiver Clock

scholarly journals Using Evolutionary Computation on GPS Position Correction

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Jung Yi Lin
Keyword(s):  
Evolutionary Computation ◽  
Global Positioning System ◽  
Handheld Devices ◽  
Correction Function ◽  
Gps Receiver ◽  
Correction Algorithm ◽  
Gps Receivers ◽  
Global Positioning ◽  
Position Correction ◽  
Hardware Reconfiguration

More and more devices are equipped with global positioning system (GPS). However, those handheld devices with consumer-grade GPS receivers usually have low accuracy in positioning. A position correction algorithm is therefore useful in this case. In this paper, we proposed an evolutionary computation based technique to generate a correction function by two GPS receivers and a known reference location. Locating one GPS receiver on the known location and combining its longitude and latitude information and exact poisoning information, the proposed technique is capable of evolving a correction function by such. The proposed technique can be implemented and executed on handheld devices without hardware reconfiguration. Experiments are conducted to demonstrate performance of the proposed technique. Positioning error could be significantly reduced from the order of 10 m to the order of 1 m.

GPS RECEIVERS TIMING DATA PROCESSING USING NEURAL NETWORKS: OPTIMAL ESTIMATION AND ERRORS MODELING

2007 ◽  
Vol 17 (05) ◽  
pp. 383-393 ◽  
Author(s):  
M. R. MOSAVI
Keyword(s):  
Neural Networks ◽  
Outdoor Recreation ◽  
Optimal Estimation ◽  
Single Frequency ◽  
Gps Receiver ◽  
Commercial Aviation ◽  
Gps Receivers ◽  
Before And After ◽  
Timing Data

The Global Positioning System (GPS) is a network of satellites, whose original purpose was to provide accurate navigation, guidance, and time transfer to military users. The past decade has also seen rapid concurrent growth in civilian GPS applications, including farming, mining, surveying, marine, and outdoor recreation. One of the most significant of these civilian applications is commercial aviation. A stand-alone civilian user enjoys an accuracy of 100 meters and 300 nanoseconds, 25 meters and 200 nanoseconds, before and after Selective Availability (SA) was turned off. In some applications, high accuracy is required. In this paper, five Neural Networks (NNs) are proposed for acceptable noise reduction of GPS receivers timing data. The paper uses from an actual data collection for evaluating the performance of the methods. An experimental test setup is designed and implemented for this purpose. The obtained experimental results from a Coarse Acquisition (C/A)-code single-frequency GPS receiver strongly support the potential of methods to give high accurate timing. Quality of the obtained results is very good, so that GPS timing RMS error reduce to less than 120 and 40 nanoseconds, with and without SA.

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