Modeling the Detection Capability of the Global IMS Infrasound Network

2018 ◽  
pp. 593-604 ◽  
Author(s):  
Alexis Le Pichon ◽  
Lars Ceranna ◽  
Julien Vergoz ◽  
Dorianne Tailpied
Keyword(s):  
Detection Capability

Detection Capability of Downlink Signals in Mobile WiMAX and 3GPP LTE with an FFT-Based UWB Receiver

2013 ◽  
Vol E96.A (1) ◽  
pp. 285-292 ◽  
Author(s):  
Kenichi TAKIZAWA ◽  
Hirotaka YAMANE ◽  
Huan-Bang LI ◽  
Feng LU ◽  
Kohei OHNO ◽  
...  
Keyword(s):  
Mobile Wimax ◽  
Detection Capability ◽  
3Gpp Lte ◽  
Uwb Receiver

scholarly journals Evaluation of Fengyun-4A Lightning Mapping Imager (LMI) Performance during Multiple Convective Episodes over Beijing

2021 ◽  
Vol 13 (9) ◽  
pp. 1746
Author(s):  
Zhixiong Chen ◽  
Xiushu Qie ◽  
Juanzhen Sun ◽  
Xian Xiao ◽  
Yuxin Zhang ◽  
...  
Keyword(s):  
Doppler Radar ◽  
Detection Efficiency ◽  
Ground Truth ◽  
Radar Data ◽  
Detection Capability ◽  
Cloud Properties ◽  
Order Of Magnitude ◽  
Total Lightning ◽  
Matching Criteria ◽  
Event Based

This study investigates the characteristics of space-borne Lightning Mapping Imager (LMI) lightning products and their relationships with cloud properties using ground-based total lightning observations from the Beijing Broadband Lightning Network (BLNET) and cloud information from S-band Doppler radar data. LMI showed generally consistent lightning spatial distributions with those of BLNET, and yielded a considerable lightning detection capability over regions with complex terrain. The ratios between the LMI events, groups and flashes were approximately 9:3:1, and the number of LMI-detected flashes was roughly one order of magnitude smaller than the number of BLNET-detected flashes. However, in different convective episodes, the LMI detection capability was likely to be affected by cloud properties, especially in strongly electrified convective episodes associated with frequent lightning discharging and thick cloud depth. As a result, LMI tended to detect lightning flashes located in weaker and shallower cloud portions associated with fewer cloud shielding effects. With reference to the BLNET total lightning data as the ground truth of observation (both intra-cloud lightning and cloud-to-ground lightning flashes), the LMI event-based detection efficiency (DE) was estimated to reach 28% under rational spatiotemporal matching criteria (1.5 s and 65 km) over Beijing. In terms of LMI flash-based DE, it was much reduced compared with event-based DE. The LMI flash-based ranged between 1.5% and 3.5% with 1.5 s and 35–65 km matching scales. For 330 ms and 35 km, the spatiotemporal matching criteria used to evaluate Geostationary Lightning Mapper (GLM), the LMI flash-based DE was smaller (<1%).

scholarly journals Source modification for efficiency enhancement of marine controlled-source electromagnetic method

2021 ◽  
Vol 18 (2) ◽  
Author(s):  
Amir Rostami ◽  
Noorhana Yahaya ◽  
Hassan Soleimani ◽  
Muhammad Rauf ◽  
Tadiwa E Nyamasvisva ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Shallow Water ◽  
Method Of Moments ◽  
Experimental Setup ◽  
Efficiency Enhancement ◽  
Shooting Methods ◽  
Detection Capability ◽  
Controlled Source ◽  
Element Simulation ◽  
Electromagnetic Source

Abstract Controlled-source electromagnetics is a strongly efficient technique to explore deep-water marine hydrocarbon reservoirs. However, the shallow-water unsolved limitations of electromagnetic shooting methods still exist. In this regard, this work aims to alter the existing conventional electromagnetic source such that it can converge the down-going electromagnetic wave while simultaneously dispersing the up-going electromagnetic energy to minimise the airwave in shallow water. This work presents computed electric current distribution inside a modified transmitter, using a method of moments. Simulation and an experiment-based methodology are applied to this work. Finite element simulation of the response of the modified transmitter displayed the capability of the new transmitter in dispersing the airwave, by 15%. The experimental setup confirmed a better performance of the new transmitter, showing hydrocarbon delineation of up to 48%, compared to the existing conventional transmitter, with 25% oil delineation at the same depths in the same environment. Modification of the electromagnetic source to unbalance the up-down signals may have the potential to enhance the delineation magnitude of the target signal and, as a result, significantly improve oil detection capability.

Analysis on the detection capability of the space-based camera for the space debris

2016 ◽  
Author(s):  
Chao Wang ◽  
Fugang Wang ◽  
Zhao Ye ◽  
Xianying Ge ◽  
Huan Yin ◽  
...  
Keyword(s):  
Space Debris ◽  
Detection Capability

scholarly journals Comparison and Validation of Acoustic Response Models for Wind Noise Reduction Pipe Arrays

2017 ◽  
Vol 34 (2) ◽  
pp. 401-414 ◽  
Author(s):  
Julien Marty ◽  
Stéphane Denis ◽  
Thomas Gabrielson ◽  
Milton Garcés ◽  
David Brown
Keyword(s):  
Noise Reduction ◽  
Acoustic Response ◽  
Detection Capability ◽  
Wind Noise ◽  
Response Models ◽  
Operational Conditions ◽  
Measurement Systems ◽  
International Monitoring ◽  
Wind Noise Reduction ◽  
Acoustic Responses

AbstractThe detection capability of the infrasound component of the International Monitoring System (IMS) is tightly linked to the performance of its wind noise reduction systems. The wind noise reduction solution implemented at all IMS infrasound measurement systems consists of a spatial distribution of air inlets connected to the infrasound sensor through a network of pipes. This system, usually referred to as “pipe array,” has proven its efficiency in operational conditions. The objective of this paper is to present the results of the comparison and validation of three distinct acoustic response models for pipe arrays. The characteristics of the models and the results obtained for a defined set of pipe array configurations are described. A field experiment using a newly developed infrasound generator, dedicated to the validation of these models, is then presented. The comparison between the modeled and empirical acoustic responses shows that two of the three models can be confidently used to estimate pipe array acoustic responses. This study paves the way to the deconvolution of IMS infrasound data from pipe array responses and to the optimization of pipe array design to IMS applications.

scholarly journals Detection Capability Verification and Performance Test for the High Resolution Imaging Camera of China’s Tianwen-1 Mission

2021 ◽  
Vol 217 (6) ◽  
Author(s):  
Wei Yan ◽  
Jianjun Liu ◽  
Xin Ren ◽  
Chunlai Li ◽  
Qiang Fu ◽  
...  
Keyword(s):  
High Resolution ◽  
Data Processing ◽  
High Resolution Imaging ◽  
Martian Surface ◽  
Detection Capability ◽  
High Quality ◽  
Mars Exploration ◽  
Imaging Camera ◽  
High Resolution Images ◽  
Resolution Imaging

AbstractHigh-resolution optical cameras have always been important scientific payloads in Mars exploration missions, which can obtain detailed images of Martian surface for the study of geomorphology, topography and geological structure. At present, there are still many challenges for Mars high-resolution images in terms of global coverage, stereo coverage (especially for colour images), and data processing methods. High Resolution Imaging Camera (HiRIC) is a high-quality, multi-mode, multi-functional, multi-spectral remote sensing camera that is suitable for the deep space developed for China’s first Mars Exploration Mission (Tianwen-1), which was successfully launched in July 2020. Here we design special experiments based on the in-orbit detection conditions of Tianwen-1 mission to comprehensively verify the detection capability and the performance of HiRIC, from the aspects of image motion compensation effect, focusing effect, image compression quality, and data preprocessing accuracy. The results showed that the performance status of HiRIC meets the requirements of obtaining high resolution images on the Martian surface. Furthermore, proposals for HiRIC in-orbit imaging strategy and data processing are discussed to ensure the acquisition of high-quality HiRIC images, which is expected to serve as a powerful complementation to the current Mars high-resolution images.

An automatic seismic signal detection algorithm based on the Walsh transform

1981 ◽  
Vol 71 (4) ◽  
pp. 1351-1360
Author(s):  
Tom Goforth ◽  
Eugene Herrin
Keyword(s):  
Signal Detection ◽  
Real Time ◽  
Seismic Signal ◽  
Detection Algorithm ◽  
Machine Language ◽  
Walsh Transform ◽  
Time Signal ◽  
Data Systems ◽  
Detection Capability ◽  
Short Period

abstract An automatic seismic signal detection algorithm based on the Walsh transform has been developed for short-period data sampled at 20 samples/sec. Since the amplitude of Walsh function is either +1 or −1, the Walsh transform can be accomplished in a computer with a series of shifts and fixed-point additions. The savings in computation time makes it possible to compute the Walsh transform and to perform prewhitening and band-pass filtering in the Walsh domain with a microcomputer for use in real-time signal detection. The algorithm was initially programmed in FORTRAN on a Raytheon Data Systems 500 minicomputer. Tests utilizing seismic data recorded in Dallas, Albuquerque, and Norway indicate that the algorithm has a detection capability comparable to a human analyst. Programming of the detection algorithm in machine language on a Z80 microprocessor-based computer has been accomplished; run time on the microcomputer is approximately 110 real time. The detection capability of the Z80 version of the algorithm is not degraded relative to the FORTRAN version.

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