RT-EQcorrscan: Near-Real-Time Matched-Filtering for Rapid Development of Dense Earthquake Catalogs

2020 ◽  
Vol 91 (6) ◽  
pp. 3574-3584
Author(s):  
Calum John Chamberlain ◽  
John Townend ◽  
Matthew C. Gerstenberger
Keyword(s):  
Real Time ◽  
Template Matching ◽  
Matched Filter ◽  
Rapid Development ◽  
Geographic Region ◽  
High Rate ◽  
Filter Method ◽  
Matched Filtering ◽  
Matched Filters ◽  
Earthquake Catalogs

Abstract Matched-filtering (template-matching) is an effective method for detecting clustered seismicity such as aftershocks, low-frequency earthquakes, repeating earthquakes, and tectonic and volcanic swarms. Several groups have developed efficient codes implementing matched-filter methods and demonstrated that earthquake catalogs can be substantially expanded using these methods. Here, we present a near-real-time implementation of the matched-filter method, designed to be used in response to ongoing seismicity. Its near-real-time capabilities enable dense catalogs of seismicity to be constructed rapidly, providing input into real-time seismic hazard and forecasting and thus informing the earthquake response and scientific understanding. Such rapid development of detailed earthquake catalogs has similar application in volcano monitoring, monitoring of induced seismicity, and for online construction of slow-earthquake catalogs. Our software package, RT-EQcorrscan, is an open-source extension of the EQcorrscan Python package. The package can either be deployed to apply near-real-time matched-filters to a specific geographic region or sequence on a continuous basis, or configured to respond to large earthquakes or high-rate sequences by automatically starting a matched-filter run in response to these events. The system relies on, and maintains, a constantly updated template database of waveforms and event metadata, which is then queried for the specific target region. This template database can be updated while the matched-filter is running to enable the set of templates to expand in response to previous results. Multiple region-specific matched-filters can be run in parallel, allowing the system to respond to distinct trigger events.

scholarly journals Real-Time Video Road Sign Detection and Tracking using Image Processing and Autonomous Car

2019 ◽  
Vol 8 (12S2) ◽  
pp. 495-500
Keyword(s):  
Image Processing ◽  
Real Time ◽  
Template Matching ◽  
High Rate ◽  
Image Processing Technique ◽  
Video Frame ◽  
Road Signs ◽  
Detection And Tracking ◽  
Road Sign ◽  
Sign Detection

Detection and monitoring of real-time road signs are becoming today's study in the autonomous car industry. The number of car users in Malaysia risen every year as well as the rate of car crashes. Different types, shapes, and colour of road signs lead the driver to neglect them, and this attitude contributing to a high rate of accidents. The purpose of this paper is to implement image processing using the real-time video Road Sign Detection and Tracking (RSDT) with an autonomous car. The detection of road signs is carried out by using Video and Image Processing technique control in Python by applying deep learning process to detect an object in a video’s motion. The extracted features from the video frame will continue to template matching on recognition processes which are based on the database. The experiment for the fixed distance shows an accuracy of 99.9943% while the experiment with the various distance showed the inversely proportional relation between distances and accuracies. This system was also able to detect and recognize five types of road signs using a convolutional neural network. Lastly, the experimental results proved the system capability to detect and recognize the road sign accurately.

scholarly journals Real-Time Coseismic Displacement Retrieval Based on Temporal Point Positioning with IGS RTS Correction Products

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 334
Author(s):  
Yuanfan Zhang ◽  
Zhixi Nie ◽  
Zhenjie Wang ◽  
Huisheng Wu ◽  
Xiaofei Xu
Keyword(s):  
Real Time ◽  
Rapid Development ◽  
Vertical Direction ◽  
High Rate ◽  
Convergence Time ◽  
Reference Station ◽  
Coseismic Displacement ◽  
Time Service ◽  
Precise Orbit ◽  
Point Positioning

With the rapid development of the global navigation satellite system (GNSS), high-rate GNSS has been widely used for high-precision GNSS coseismic displacement retrieval. In recent decades, relative positioning (RP) and precise point positioning (PPP) are mainly adopted to retrieve coseismic displacements. However, RP can only obtain relative coseismic displacements with respect to a reference station, which might be subject to quaking during a large seismic event. While PPP needs a long (re)convergence period of tens of minutes. There is no convergence time needed in the variometric approach for displacements analysis standalone engine (VADASE) but the derived displacements are accompanied by a drift. Temporal point positioning (TPP) method adopts temporal-differenced ionosphere-free phase measurements between a reference epoch and the current epoch, and there is almost no drift in the displacement derived from TPP method. Nevertheless, the precise orbit and clock products should be applied in the TPP method. The studies in recent years are almost based on the postprocessing precise orbits and clocks or simulated real-time products. Since 2013, international GNSS service (IGS) has been providing an open-access real-time service (RTS), which consists of orbit, clock and other corrections. In this contribution, we evaluated the performance of real-time coseismic displacement retrieval based on TPP method with IGS RTS correction products. At first, the real-time precise orbit and clock offsets are derived from the RTS correction products. Then, the temporal-differenced ionosphere-free (IF) combinations are formed and adopted as the TPP measurements. By applying real-time precise orbit and clock offsets, the coseismic displacement can be real-timely retrieved based on TPP measurements. To evaluate the accuracy, two experiments including a stationary experiment and an application to an earthquake event were carried out. The former gives an accuracy of 1.8 cm in the horizontal direction and 4.1 cm in the vertical direction during the whole period of 15-min. The latter gives an accuracy of 1.2 cm and 2.4 cm in the horizontal and vertical components, respectively.

scholarly journals A Truncated Matched Filter Method for Interrupted Sampling Repeater Jamming Suppression Based on Jamming Reconstruction

2021 ◽  
Vol 14 (1) ◽  
pp. 97
Author(s):  
Lu Lu ◽  
Meiguo Gao
Keyword(s):  
Time Delay ◽  
Theoretical Analysis ◽  
Numerical Simulations ◽  
Frequency Modulation ◽  
Pulse Compression ◽  
Matched Filter ◽  
Filter Method ◽  
Matched Filters ◽  
Digital Radio ◽  
Real Target

Interrupted sampling repeater jamming (ISRJ) is becoming more widely used in electronic countermeasures (ECM), thanks to the development of digital radio frequency memory (DRFM). Radar electronic counter-countermeasure (ECCM) is much more difficult when the jamming signal is coherent with the emitted signal. Due to the intermittent transmission feature of ISRJ, the energy accumulation of jamming on the matched filter shows a ‘ladder’ characteristic, whereas the real target signal is continuous. As a consequence, the time delay and distribution of the jamming slice can be obtained based on searching the truncated-matched-filter (TMF) matrix. That is composed of pulse compression (PC) results under matched filters with different lengths. Based on the above theory, this paper proposes a truncated matched filter method by the reconstruction of jamming slices to suppress ISRJ of linear frequency modulation (LFM) radars. The numerical simulations indicate the effectiveness of the proposed method and validate the theoretical analysis.

scholarly journals Target tracking accuracy and latency with different 4D ultrasound systems – a robotic phantom study

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Svenja Ipsen ◽  
Sven Böttger ◽  
Holger Schwegmann ◽  
Floris Ernst
Keyword(s):  
Target Tracking ◽  
Real Time ◽  
Template Matching ◽  
Image Data ◽  
Distinct Advantage ◽  
Reference Trajectory ◽  
Data Streaming ◽  
Tracking Accuracy ◽  
Time Data ◽  
4D Ultrasound

AbstractUltrasound (US) imaging, in contrast to other image guidance techniques, offers the distinct advantage of providing volumetric image data in real-time (4D) without using ionizing radiation. The goal of this study was to perform the first quantitative comparison of three different 4D US systems with fast matrix array probes and real-time data streaming regarding their target tracking accuracy and system latency. Sinusoidal motion of varying amplitudes and frequencies was used to simulate breathing motion with a robotic arm and a static US phantom. US volumes and robot positions were acquired online and stored for retrospective analysis. A template matching approach was used for target localization in the US data. Target motion measured in US was compared to the reference trajectory performed by the robot to determine localization accuracy and system latency. Using the robotic setup, all investigated 4D US systems could detect a moving target with sub-millimeter accuracy. However, especially high system latency increased tracking errors substantially and should be compensated with prediction algorithms for respiratory motion compensation.

scholarly journals High-Rate Transition Metal-based Cathode Materials for Battery-Supercapacitor Hybrid Devices

2021 ◽  
Author(s):  
Cong Wang ◽  
Zehao Song ◽  
Pei Shi ◽  
Lin Lv ◽  
Houzhao Wan ◽  
...  
Keyword(s):  
Large Scale ◽  
Rapid Development ◽  
Electronic Devices ◽  
High Rate ◽  
Specific Power ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Electrochemical Devices ◽  
Hybrid Devices ◽  
Scale Grid

With the rapid development of portable electronic devices, electric vehicles and large-scale grid energy storage devices, it needs to reinforce specific energy and specific power of related electrochemical devices meeting...

scholarly journals Phone-Based Restaurant Recommendation System by Using Position Information and Association Rules

2012 ◽  
Vol 6-7 ◽  
pp. 783-789
Author(s):  
Jian Feng Dong ◽  
Tian Yang Dong ◽  
Jia Jie Yao ◽  
Ling Zhang
Keyword(s):  
Mobile Phone ◽  
Real Time ◽  
Association Rules ◽  
Recommendation System ◽  
Rapid Development ◽  
Smart Phone ◽  
Smart Phones ◽  
Location Information ◽  
Position Information ◽  
The Real

With the rapid development of smart-phone applications, how to make the ordering process via smart-phones more convenient and intelligent has become a hotspot. This paper puts forward a method of restaurant dish recommendation relying on position information and association rules. In addition, this paper has designed and developed a restaurant recommendation system based on mobile phone. The system would fetch the real-time location information via smart-phones, and provide customers personalized restaurant and dish recommendation service. According to the related applications, this system can successfully recommend the related restaurants and food information to customers.

Sign in / Sign up

Export Citation Format

Share Document