Real-Time Tsunami Detection with Oceanographic Radar Based on Virtual Tsunami Observation Experiments

The tsunami generated by the 2011 Tohoku-Oki earthquake was the first time that the velocity fields of a tsunami were measured by using high-frequency oceanographic radar (HF radar) and since then, the development of HF radar systems for tsunami detection has progressed. Here, a real-time tsunami detection method was developed, based on virtual tsunami observation experiments proposed by Fuji et al. In the experiments, we used actual signals received in February 2014 by the Nagano Japan Radio Co., Ltd. radar system installed on the Mihama coast and simulated tsunami velocities induced by the Nankai Trough earthquake. The tsunami was detected based on the temporal change in the cross-correlation of radial velocities between two observation points. Performance of the method was statistically evaluated referring to Fuji and Hinata. Statistical analysis of the detection probability was performed using 590 scenarios. The maximum detection probability was 15% at 4 min after tsunami occurrence and increased to 80% at 7 min, which corresponds to 9 min before tsunami arrival at the coast. The 80% detection probability line located 3 km behind the tsunami wavefront proceeded to the coast as the tsunami propagated to the coast. To obtain a comprehensive understanding of the tsunami detection probability of the radar system, virtual tsunami observation experiments are required for other seasons in 2014, when the sea surface state was different from that in February, and for other earthquakes.

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Real-time procedures implemented within coastal HF radar system in the northern Adriatic

OCEANS 2009-EUROPE ◽

10.1109/oceanse.2009.5278351 ◽

2009 ◽

Cited By ~ 1

Author(s):

I. Vilibic ◽

V. Dadic ◽

D. Ivankovic ◽

S. Muslim ◽

J. Sepic ◽

...

Keyword(s):

Real Time ◽

Radar System ◽

Hf Radar ◽

Northern Adriatic

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Error analyses of a multistatic meteor radar system to obtain a three-dimensional spatial-resolution distribution

Atmospheric Measurement Techniques ◽

10.5194/amt-14-3973-2021 ◽

2021 ◽

Vol 14 (5) ◽

pp. 3973-3988

Author(s):

Wei Zhong ◽

Xianghui Xue ◽

Wen Yi ◽

Iain M. Reid ◽

Tingdi Chen ◽

...

Keyword(s):

Spatial Resolution ◽

Measurement Errors ◽

Dimensional Space ◽

Lower Thermosphere ◽

Three Dimensional ◽

Radar System ◽

Meteor Radar ◽

Radar Systems ◽

Good Spatial Resolution ◽

First Time

Abstract. In recent years, the concept of multistatic meteor radar systems has attracted the attention of the atmospheric radar community, focusing on the mesosphere and lower thermosphere (MLT) region. Recently, there have been some notable experiments using such multistatic meteor radar systems. Good spatial resolution is vital for meteor radars because nearly all parameter inversion processes rely on the accurate location of the meteor trail specular point. It is timely then for a careful discussion focused on the error distribution of multistatic meteor radar systems. In this study, we discuss the measurement errors that affect the spatial resolution and obtain the spatial-resolution distribution in three-dimensional space for the first time. The spatial-resolution distribution can both help design a multistatic meteor radar system and improve the performance of existing radar systems. Moreover, the spatial-resolution distribution allows the accuracy of retrieved parameters such as the wind field to be determined.

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Design of Optimized Coded LFM Waveform for Spectrum Shared Radar System

Sensors ◽

10.3390/s21175796 ◽

2021 ◽

Vol 21 (17) ◽

pp. 5796

Author(s):

Dong-Hoon Kim ◽

Hyung-Jung Kim ◽

Jae-Han Lim

Keyword(s):

Remote Sensing ◽

Computer Simulations ◽

Cross Correlation ◽

Signal Transmission ◽

Radar System ◽

Weighted Sum ◽

Simple Scheme ◽

Optimization Framework ◽

Radar Systems ◽

Orthogonal Codes

To meet the increasing demands for remote sensing, a number of radar systems using Linear Frequency Modulation (LFM) waveforms have been deployed, causing the problem of depleting frequency resources. To address this problem, several researchers have proposed the Spectrum Shared Radar System (SSRS) in which multiple radars share the same frequency band to transmit and receive their own signals. To mitigate the interferences caused by the signal transmission by other radars, SSRS employs orthogonal waveforms that inherit the orthogonality of the waveforms from orthogonal codes. However, the inherited orthogonality of the codes is significantly reduced when incorporating LFM waveforms with the codes. To solve this problem, in this paper, we propose a novel but simple scheme for generating a set of optimized coded LFM waveforms via new optimization framework. In the optimization framework, we minimize the weighted sum of autocorrelation sidelobe peaks (ASP) and cross-correlation peaks (CP) of the coded LFM waveforms to maximize the orthogonality of the waveforms. Through computer simulations, we show that the waveforms generated by the proposed scheme outperform the waveforms created by previous proposals in terms of ASP and CP.

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Error analyses of a multistatic meteor radar system to obtain a 3-dimensional spatial resolution distribution

10.5194/amt-2020-353 ◽

2020 ◽

Author(s):

Wei Zhong ◽

Xianghui Xue ◽

Wen Yi ◽

Iain M. Reid ◽

Tingdi Chen ◽

...

Keyword(s):

Spatial Resolution ◽

Measurement Errors ◽

Dimensional Space ◽

Lower Thermosphere ◽

Radar System ◽

Meteor Radar ◽

3 Dimensional ◽

Radar Systems ◽

Good Spatial Resolution ◽

First Time

Abstract. In recent years, the concept of multistatic meteor radar systems has attracted the attention of the atmospheric radar community, focusing on the mesosphere and lower thermosphere (MLT). Recently, there have been some notable experiments using multistatic meteor radar systems (Chau et al., 2019; Spargo et al., 2019; Stober and Chau, 2015; Stober et al., 2018). Good spatial resolution is vital for meteor radars because nearly all parameter inversion processes rely on the accurate location of the meteor trail reflecting points. It is timely then for a careful discussion focussed on the error distribution of multistatic meteor radar systems. In this study, we discuss the measurement errors that affect the spatial resolution and obtain the resolution distribution in 3-dimensional space for the first time. The spatial resolution distribution can both help design a multistatic meteor radar system and improve the performance of existing radar systems. Moreover, the spatial resolution distribution allows the accuracy of retrieved parameters such as the wind field to be determined.

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Deteksi Radar Pasif menggunakan GNU Radio dan SDR pada Frekuensi Televisi

ELKOMIKA Jurnal Teknik Energi Elektrik Teknik Telekomunikasi & Teknik Elektronika ◽

10.26760/elkomika.v8i3.505 ◽

2020 ◽

Vol 8 (3) ◽

pp. 505

Author(s):

YONATAN EDWIN MARPAUNG ◽

ALOYSIUS ADYA PRAMUDITA ◽

ERFANSYAH ALI

Keyword(s):

Software Defined Radio ◽

Cross Correlation ◽

Moving Objects ◽

Radar System ◽

Digital Television ◽

Passive Radar ◽

Gnu Radio ◽

Delay Test ◽

Radar Systems ◽

Television Receiver

ABSTRAKRadar pasif adalah salah satu jenis sistem radar bistatic dimana transmitter dan receiver berada di tempat berbeda. Sistem radar pasif dapat memaanfaatkan frekuensi siaran televisi yang tersedia sebagai sumber transmitter. Pada penelitian ini, radar pasif dibuat dengan Sofware Defined Radio (SDR) sebagai sistem komunikasi yang dapat mengkofigurasi penerima televisi digital sdr-dongle RTL2832U yang dimodifikasi dan perangkat lunak GNU Radio. Hasil pengujian delay pada gelombang 1,2,3 untuk objek manusia adalah 0,192, 0,36 dan 0,53 detik, untuk objek sepeda adalah 0,332, 0,5 dan 0,67, untuk objek motor adalah 0,422, 0,69 dan 0,86 detik, untuk objek mobil adalah 0,538, 0,7 dan 0,87 detik sehingga dapat disimpulkan bahwa sistem radar pasif yang dirancang dapat mendeteksi benda bergerak dimana pegerakan target menyebabkan pergeseran puncak Cross-Correlation.Kata kunci: Radar Pasif, Cross-Correlation, SDR, Frekuensi Televisi, RTL2832U ABSTRACTPassive radar is a type of bistatic radar system where the transmitter and receiver are in different places. Passive radar systems can utilize the available television broadcast frequencies as transmitter sources. In this study, passive radar is made with Software Defined Radio (SDR) as a communication system that can configure a modified RTL2832U sdr-dongle digital television receiver and GNU Radio software. The delay test results on waves 1,2,3 for human objects are 0.192, 0.36 and 0.53 seconds, for bicycle objects are 0.332, 0.5 and 0.67, for motor objects are 0.422, 0.69 and 0.86 seconds, for car objects are 0.538, 0.7 and 0.87 seconds so it can be concluded that the passive radar system is designed to detect moving objects where moving targets causes a shift in the peak of Cross-Correlation.Keywords: Passive Radar, Cross-Correlation, SDR, Television Frequency, RTL2832U

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Development and Application of Quality Control System for Highway Subgrade Construction

智能城市应用 ◽

10.33142/sca.v2i5.814 ◽

2019 ◽

Vol 2 (5) ◽

Author(s):

Tong Wang

Keyword(s):

Quality Control ◽

Real Time ◽

Detection Method ◽

System Development ◽

Effective Control ◽

Construction Process ◽

Development Mode ◽

The Road ◽

Whole Process

The compaction quality of the subgrade is directly related to the service life of the road. Effective control of the subgrade construction process is the key to ensuring the compaction quality of the subgrade. Therefore, real-time, comprehensive, rapid and accurate prediction of construction compaction quality through informatization detection method is an important guarantee for speeding up construction progress and ensuring subgrade compaction quality. Based on the function of the system, this paper puts forward the principle of system development and the development mode used in system development, and displays the development system in real-time to achieve the whole process control of subgrade construction quality.

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Real-Time Line Detection Method for Camera Images of the Rescue Robot

IEEJ Transactions on Electronics Information and Systems ◽

10.1541/ieejeiss.130.2039 ◽

2010 ◽

Vol 130 (11) ◽

pp. 2039-2046

Author(s):

Munetoshi Numada ◽

Masaru Shimizu ◽

Takuma Funahashi ◽

Hiroyasu Koshimizu

Keyword(s):

Real Time ◽

Detection Method ◽

Line Detection ◽

Time Line ◽

Rescue Robot

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Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

10.26434/chemrxiv.7098695 ◽

2018 ◽

Author(s):

Elaine A. Kelly ◽

Judith E. Houston ◽

Rachel Evans

Keyword(s):

Real Time ◽

Absorption Spectroscopy ◽

Self Assembly ◽

Uv Light ◽

Wormlike Micelles ◽

Tetraethylene Glycol ◽

Light Illumination ◽

First Time ◽

Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such asdrug delivery and micellar catalysis. Currently, their behaviour in the equilibrium cis-and trans-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C8AzoOC8E4) using small-angle neutron scattering (SANS). We show that the incorporation of in-situUV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C8AzoOC8E4could switch between wormlike micelles (transnative state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked in-situthrough combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

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