detector performance
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Galaxies ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 12
Author(s):  
Derek Davis ◽  
Marissa Walker

Since the early stages of operation of ground-based gravitational-wave interferometers, careful monitoring of these detectors has been an important component of their successful operation and observations. Characterization of gravitational-wave detectors blends computational and instrumental methods of investigating the detector performance. These efforts focus both on identifying ways to improve detector sensitivity for future observations and understand the non-idealized features in data that has already been recorded. Alongside a focus on the detectors themselves, detector characterization includes careful studies of how astrophysical analyses are affected by different data quality issues. This article presents an overview of the multifaceted aspects of the characterization of interferometric gravitational-wave detectors, including investigations of instrumental performance, characterization of interferometer data quality, and the identification and mitigation of data quality issues that impact analysis of gravitational-wave events. Looking forward, we discuss efforts to adapt current detector characterization methods to meet the changing needs of gravitational-wave astronomy.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Cundong Tang ◽  
Li Chen ◽  
Yi Wang ◽  
Wusi Yang ◽  
Rui Chen ◽  
...  

With the development of information technology in the network era and the popularization of the 5G era, UAV-related applications are becoming more and more widely used, which is one of the essential basic technologies. Therefore, the technology has great research value and practical significance, a multiobjective detector based on support vector machine (SVM) is designed based on directional gradient histogram (HOG), and the startup method used with cross-validation methods can improve detector performance. It makes the detector accuracy above 98% and has good resistance to the target scale. A real-time target tracker is designed with its rotation variation and with an improved average displacement algorithm. The algorithm must manually select the target model and suggest the target model to achieve automatic acquisition of the target model. Due to the ambiguity of the target tracking state, several judgment conditions are set to determine whether the tracking has failed and whether the tracker state is correctly verified, with several similar target tracking algorithms. When the system is started, the system detects targets frame by frame. And it will locate a possible target by color segmentation and specify the target to be tracked to recommend the relevant model during the tracking process and open the tracker to determine the target tracking state frame by frame and perform target detection at each frame. Then it will find possible goals and will follow them to achieve a balance of stable and real-time system performance, using the results of the TPD-KCF method. The percentage of correctly tracking images can reach 98%, and the efficiency is significantly improved.


2021 ◽  
pp. 1-13
Author(s):  
Nestor J. Zaluzec

A wide range of X-ray detectors and geometries are available today on transmission/scanning transmission analytical electron microscopes. While there have been numerous reports of their individual performance, no single experimentally reproducible metric has been proposed as a basis of comparison between the systems. In this paper, we detail modeling, experimental procedures, measurements, and specimens which can be used to provide a manufacturer-independent assessment of the performance of an analytical system. Using these protocols, the geometrical collection efficiency, system peaks, and minimum detection limits can be independently assessed and can be used to determine the best conditions to conduct modern hyperspectral and/or spectrally resolved tomographic analyses for an individual instrument. A simple analytical formula and specimen is presented which after suitable system calibrations can be used to experimentally determine the X-ray detector solid angle.


2021 ◽  
Vol 81 (12) ◽  
Author(s):  
Meng Li ◽  
Yuansheng Yang ◽  
Peng Ma ◽  
Junwei Zhang ◽  
Zhi Qin ◽  
...  

AbstractA new Frisch-grid ionization chamber has been built to explore the appropriate choice of Frisch-grid. Detailed studies of the relationship between grid geometries and detector performance have been performed with an $$^{241}$$ 241 Am source. This paper describes and compares the energy resolution of ionization chambers with parallel-wire and mesh grids of different grid parameters. Some specific recommendations for grid selection are provided based on the data currently available. To obtain optimal energy resolution, the operating voltage of the chamber must satisfy the condition of minimum electron collection on the grid with distinct geometries and parameters, respectively. Since there is no established theory applicable to both types of grids, we have devised a careful simulation procedure incorporating the COMSOL and Garfield++ codes to search for the conditions of the minimum electron collection on the grid. The simulation results fit the experimental data well, suggesting that this simulation method successfully predicts the suitable voltage setting when using a mesh grid or parallel wires grid as the shielding electrode.


Author(s):  
Guanghui Li ◽  
PengBo Wang ◽  
XinRan He ◽  
YuLong Meng ◽  
Feng Liang ◽  
...  

Abstract We used the metal-organic chemical vapor deposition(MOCVD) method to grow AlN material on a c-plane sapphire substrate and fabricate an AlN-based metal-semiconductor-metal (MSM) detector. Analyzing the influence mechanism of different dislocation densities in AlN materials and detector electrode structure on the detector performance, it was found that the lower the dislocations can effectively reduce the dark current of the detector under zero bias voltage, and help improve the performance of the detector. The study also found that when the finger spacing of the detector remained the same and the finger width increased, the efficiency of the detector decreased, while the response time of the detector increased, when the finger width of the detector electrodes remained unchanged and the finger spacing increased, the response time of the detector increased. Therefore, the electrode finger width and finger spacing must be compromised in the design of the electrode structure to improve the performance of the AlN-based MSM detector.


Author(s):  
Ravi Shankar ◽  
T. V. Ramana ◽  
Preeti Singh ◽  
Sandeep Gupta ◽  
Haider Mehraj

This paper investigates deep learning (DL) non-orthogonal multiple access (NOMA) receivers based on long short-term memory (LSTM) under Rayleigh fading channel circumstances. The performance comparison between the DL NOMA detector and the traditional NOMA method is established, and results have shown that the DL-based NOMA detector performance is far better in comparison with conventional NOMA detectors. Simulation curves are compared with the performance of the DL detector in terms of minimum mean square estimate (MMSE) and least square error (LSE) estimate, taking all realistic circumstances, except the cyclic prefix (CP), and clipping distortion into account. The simulation curves demonstrate that the performance of the DL-based detector is exceptionally good when it equals 1 when the noise signal ratio (SNR) is more than 15 dB, assuming that the DL method is more resilient to clipping distortion.


2021 ◽  
Vol 13 (22) ◽  
pp. 4578
Author(s):  
Dong L. Wu ◽  
Donald E. Jennings ◽  
Kwong-Kit Choi ◽  
Murzy D. Jhabvala ◽  
James A. Limbacher ◽  
...  

The demonstration of a newly developed compact thermal imager (CTI) on the International Space Station (ISS) has provided not only a technology advancement but a rich high-resolution dataset on global clouds, atmospheric and land emissions. This study showed that the free-running CTI instrument could be calibrated to produce scientifically useful radiance imagery of the atmosphere, clouds, and surfaces with a vertical resolution of ~460 m at limb and a horizontal resolution of ~80 m at nadir. The new detector demonstrated an excellent sensitivity to detect the weak limb radiance perturbations modulated by small-scale atmospheric gravity waves. The CTI’s high-resolution imaging was used to infer vertical cloud temperature profiles from a side-viewing geometry. For nadir imaging, the combined high-resolution and high-sensitivity capabilities allowed the CTI to better separate cloud and surface emissions, including those in the planetary boundary layer (PBL) that had small contrast against the background surface. Finally, based on the ISS’s orbit, the stable detector performance and robust calibration algorithm produced valuable diurnal observations of cloud and surface emissions with respect to solar local time during May–October 2019, when the CTI had nearly continuous operation.


2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Hamzeh Ghahramani ◽  
Naser Parhizgar ◽  
Bijan Abbasi Arand ◽  
Morteza Barari

This paper first establishes a new complex independent component analysis (cICA) algorithm based on the spatiotemporal extension of complex-valued entropy bound minimization (CEBM) to separate received complex-valued radar signals. Next, we propose a new cICA-based detector with an open structure to find Swerling model targets, lognormal targets, and sea-surface small floating targets in coherent high-resolution maritime surveillance radars. The detector encountered three major problems when adopting cICA for detection and solved them using three effective suggestions. After performing cICA on the time series received by the radar, we obtained two different sources. Using the first and second theoretical and empirical moment estimates of the K-distribution, the target was selected between these two output source signals. Detector performance was verified quantitatively and qualitatively using the real-life IPIX radar database. Comprehensive experiments on this database with synthetic injected targets showed promising results. The computational time and sample size dependency of the proposed cICA algorithm were also discussed. Finally, a comparison of the detector with several novel detectors for detecting sea-surface floating small targets of the IPIX radar database demonstrated the proposed detector’s superiority.


2021 ◽  
Vol 136 (11) ◽  
Author(s):  
Patrizia Azzi ◽  
Emmanuel Perez

AbstractCircular colliders have the advantage of delivering collisions to multiple interaction points, which allow different detector designs to be studied and optimised—up to four for FCC-ee. On the one hand, the detectors must satisfy the constraints imposed by the invasive interaction region layout. On the other hand, the performance of heavy-flavour tagging, of particle identification, of tracking and particle-flow reconstruction, and of lepton, jet, missing energy and angular resolution, need to match the physics programme and the exquisite statistical precision offered by FCC-ee. During the FCC feasibility study (2021–2025), benchmark physics processes will be used to determine, via appropriate simulations, the requirements on the detector performance or design that must be satisfied to ensure that the systematic uncertainties of the measurements are commensurate with their statistical precision. The usage of the data themselves, in order to reach the challenging goals on the stability and on the alignment of the detector, in particular for the programme at and around the Z peak, will also be studied. In addition, the potential for discovering very weakly coupled new particles, in decays of Z or Higgs bosons, could motivate dedicated detector designs that would increase the efficiency for reconstructing the unusual signatures of such processes. These studies are crucial input to the further optimisation of the two concepts described in the FCC-ee conceptual design report, CLD and IDEA, and to the development of new concepts which might actually prove to be better adapted to the FCC-ee physics programme, or parts thereof.


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