EVALUATION OF TWO EFFICIENT TARGET TRACKING ALGORITHMS FOR MATCHED-FIELD PROCESSING WITH HORIZONTAL ARRAYS

1995 ◽  
Vol 03 (04) ◽  
pp. 311-326 ◽  
Author(s):  
MICHAEL J. WILMUT ◽  
JOHN M. OZARD ◽  
PETER BROUWER
Keyword(s):  
Target Tracking ◽  
Signal To Noise Ratio ◽  
Signal Strength ◽  
Detection Performance ◽  
Performance Difference ◽  
Source Position ◽  
Acoustic Source ◽  
Signal To Noise ◽  
Matched Field Processing ◽  
Tracking Algorithms

A tracking algorithm may be used to reduce the ambiguity of the positions of a moving underwater acoustic source. The objective of this paper is to evaluate two efficient target tracking algorithms suitable for use with Matched-Field Processing (MFP). The detection after tracking algorithms described here are applicable to targets moving linearly at constant speed and depth that produce low Signal-to-Noise Ratio (SNR) signals at the receivers. The input to the tracker consists of the positions of the largest Bartlett statistics or peaks on the MFP ambiguity surfaces. Even at very low SNRs, these largest peaks usually include the match at or near the source position sufficiently often that the detection performance of our efficient tracker rivals that of an exhaustive tracker. In this paper efficient algorithms are developed and evaluated based on examining either the sum of the uniformly weighted Bartlett array outputs or the sum of the Bartlett array outputs weighted by predicted received signal strength. This sum is evaluated along a set of linear tracks that connect the largest peaks. Detection performance is shown to be better for the signal-strength weighted tracker. The performance difference is largest for tracks along a constant bearing from the array.

scholarly journals Analisis Kualitas Sinyal Jaringan WLAN Terhadap Layout Ruangan di Politeknik Negeri Lhokseumawe

2019 ◽  
Vol 16 (1) ◽  
pp. 7
Author(s):  
Aida Wulandari ◽  
Yassir Yassir ◽  
Hanafi Hanafi
Keyword(s):  
Signal To Noise Ratio ◽  
Signal Strength ◽  
Signal To Noise ◽  
Noise Ratio

Pemanfaatan Wi-Fi dalam sistem komunikasi data berbasis wireless, menjadi pilihan oleh banyak pengguna karena keunggulan mobilitasnya. Dalam sistem komunikasi ini, kualitas signal strength dan SNR menjadi sangat penting dalam mencapai layanan sistem komunikasi yang handal. Kehandalan tersebut dapat diketahui dengan melakukan uji kualitas signal strength dan SNR yang dapat diberikan oleh sebuah perangkat Wi-FI melalui pengukuran. Pengukuran kualitas signal strength dan SNR dilaksanakan pada tiga model ruangan berbeda. Ruang pertama adalah ruang indoor terbuka bertempat di auditorium, ruang kedua adalah ruang semi indoor bertempat di ruang perpustakaan, dan ruang ketiga adalah ruang indoor tertutup bertempat di Gedung 3 Jurusan Teknik Elektro. Sistem menggunakan Wi-Fi yang beroperasi pada frekuensi kerja 2,4 GHz. Pengumpulan data dilakukan pada beberapa titik dalam ruangan dengan memvariasikan jarak antara pemancar dan penerima. Nilai signal strenght pada ruang indoor terbuka tertinggi diperoleh -49 dBm dan terendah -62 dBm, nilai signal strength pada ruang semi indoor tertinggi -51,6 dBm dan terendah 91,2 dBm, dan nilai signal strength pada ruang indoor tertutup -70,4 dBm dan terendah -85 dBm. Nilai SNR tertinggi pada ruang indoor terbuka diperoleh 48 dB dan terendah 38,6 dB, nilai SNR tertinggi pada ruang semi indoor diperoleh 47,2 dB dan terendah 20 dB, dan nilai SNR tertinggi pada ruang indoor tertutup diperoleh 31 dB dan terendah 21,2 dB.Kata-kata kunci: Wi-Fi, Signal Strength, Signal To Noise Ratio, pathloss, frekuensi, WLAN, hardware, sofware

Sonar target tracking incorporating uncertain estimates of signal to noise ratio

2007 ◽  
Vol 121 (5) ◽  
pp. 3172-3172
Author(s):  
Warren L. J. Fox ◽  
James W. Pitton ◽  
Eric A. Rust
Keyword(s):  
Target Tracking ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Noise Ratio

Pitfalls in horizon autopicking

2015 ◽  
Vol 3 (1) ◽  
pp. SB1-SB4 ◽  
Author(s):  
Donald A. Herron
Keyword(s):  
Data Quality ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Tracking Algorithms ◽  
Input Control ◽  
Noise Ratio ◽  
Selection Of

Interpreters use horizon autopicking in many seismic interpretations in the modern workstation environment. When properly used and with data quality permitting this technique enables efficient and accurate tracking of horizons but is not without its pitfalls. Four common pitfalls are improper selection of the input control or seed grid, not accounting for the “directional” behavior of tracking algorithms, attempting autopicking in areas with poor reflection continuity and/or low signal-to-noise ratio, and failing to recognize elements of geology that are not suitable for autopicking.

A NEW TECHNIQUE FOR THE STUDY OF SCATTER PROPAGATION IN THE TROPOSPHERE

1957 ◽  
Vol 35 (8) ◽  
pp. 823-830 ◽  
Author(s):  
J. H. Chapman ◽  
W. J. Heikkila ◽  
J. E. Hogarth
Keyword(s):  
Power Spectrum ◽  
Communication System ◽  
Carrier Frequency ◽  
Signal To Noise Ratio ◽  
Signal Strength ◽  
Noise Power ◽  
Signal To Noise ◽  
A New Technique ◽  
Conventional Signal ◽  
Noise Power Density

The power spectrum of the fluctuations in received signal strength on a near-optical U.H.F. circuit has been measured. The sidebands associated with these fluctuations can overlap the information-carrying sidebands of a communication system. When this happens, these sidebands must be taken into account in determining the signal-to-noise ratio of the system. In other words, the fluctuations then have the characteristics of noise, and therefore they are called propagation noise in the present paper. Experiments at a carrier frequency of 500 Mc. have shown that the propagation noise power density usually varies with sideband frequency ƒ (measured from the carrier) as 1/ƒ2, for f in the range 0.1 to 10 c.p.s. Departures from this law have been observed in the regions near 0.1 c.p.s. and 10 c.p.s. The measurement of the power spectrum directly offers several advantages over the conventional signal strength recording method, and these are discussed herein.

An Analysis of Infrared Spectroscopic Geometries

1997 ◽  
Vol 477 ◽  
Author(s):  
Gregory T. Merklin ◽  
Huihong Luo ◽  
Christopher E. D. Chidsey
Keyword(s):  
Vibrational Mode ◽  
Signal To Noise Ratio ◽  
Signal Strength ◽  
Internal Reflection ◽  
Infrared Spectrometry ◽  
Vibrational Modes ◽  
Signal To Noise ◽  
Transmission Spectroscopy ◽  
Infrared Spectroscopic ◽  
Experimental Geometry

ABSTRACTThe influence of experimental geometry on the signal strength and signal-to-noise ratio of infrared spectrometry has been investigated. In general, it was found that the choice of optimum experimental geometry depended on the orientation of the vibrational mode being investigated. In particular, it has been calculated that internal reflection spectrometry is relatively insensitive to vibrational modes perpendicular to the surface relative to transmission spectroscopy at Brewster's angle, and this has been confirmed by experiment.

TRAVELING SIGNAL‐TO‐NOISE RATIO AND SIGNAL POWER ESTIMATES

Geophysics ◽  
1967 ◽  
Vol 32 (3) ◽  
pp. 485-493 ◽  
Author(s):  
S. M. Simpson
Keyword(s):  
Seismic Noise ◽  
Signal To Noise Ratio ◽  
Signal Strength ◽  
Noise Removal ◽  
Statistical Properties ◽  
Signal Power ◽  
Signal To Noise ◽  
Direct Estimation ◽  
Noise Ratio

Undesirable seismic noise of a nondeterministic type must be destroyed by making use of its statistical properties. Averaging of one sort or another provides methods for performing this noise removal. Our purpose here is to present a method for direct estimation of signal strength versus seismogram time, with stepout as a parameter. After describing the method and its expected behavior to some extent, we illustrate its application to a set of three noisy records.

scholarly journals Handclap for Acoustic Measurements: Optimal Application and Limitations

Acoustics ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 224-245 ◽  
Author(s):  
Nikolaos M. Papadakis ◽  
Georgios E. Stavroulakis
Keyword(s):  
Signal To Noise Ratio ◽  
Low Frequency ◽  
Acoustic Parameter ◽  
Reverberation Time ◽  
Octave Band ◽  
Acoustic Measurements ◽  
Frequency Range ◽  
Acoustic Source ◽  
Signal To Noise ◽  
Acoustic Parameters

Handclap is a convenient and useful acoustic source. This study aimed to explore its optimal application and limitations for acoustic measurements as well for other possible utilizations. For this purpose, the following steps were performed: investigation of the optimal hand configuration for acoustic measurements and measurements at different microphone source distances and at different spaces and positions. All measurements were performed with a handclap and a dodecahedron speaker for comparison. The results indicate that the optimal hand configuration (among 11) is with the hands cupped and held at an angle due to the superior low frequency spectrum. This configuration produced usable acoustic parameter measurements in the low frequency range in common room background levels unlike other configurations. The reverberation time was measured across different spaces and positions with a deviation less than three and just a noticeable difference of the signal-to-noise ratio within or near the ISO 3382-1 limits for each corresponding octave band. Other acoustic parameters (i.e., early decay time, clarity) were measured with greater deviations for reasons discussed in the text. Finally, practical steps for measurements with a handclap as an acoustic source are suggested.

scholarly journals An Audio Distortion Dynamic Range Index for Evaluating the Performance of Audio Systems

2020 ◽  
Vol 10 (22) ◽  
pp. 8022
Author(s):  
Desheng Wang ◽  
Yangjie Wei ◽  
Yi Wang ◽  
Jing Wang
Keyword(s):  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Measurement Methods ◽  
Performance Difference ◽  
Critical Factors ◽  
Signal To Noise ◽  
Measurement Condition ◽  
Actual Application ◽  
The Impact

The dynamic range (DR) index lacking of an official definition leads to ambiguities in performance evaluation. The existing measurement methods of DR do not always match with the various actual application conditions, and some detailed distortion behavior of the device under test (DUT) is not extracted. In this paper, a new index for evaluating the DR performance of audio systems is proposed and validated, herein referred to as the audio distortion dynamic range (ADDR). It reduces the uncertainty of measurement conditions by an explicit definition and unifies the signal-to-noise ratio (SNR) and the signal-to-noise-and-distortion ratio (SINAD) indexes if under the same measurement condition. Moreover, to comprehensively reflect the impact of harmonic, spurious, and noise components on the DUT, the definitions of the traditional indexes based on classification of distorted components are replaced by the variable thresholds in the ADDR definition. Subsequently, the detailed steps of ADDR and the critical factors influencing its accuracy, are analyzed and then the optimized measurement conditions are given. Experiments based on simulated DUTs show the ADDR index can distinguish performance difference that the traditional indexes cannot distinguish, which proves it is an effective supplementary to the existing indexes in some real applications.

scholarly journals Increasing pupil size is associated with improved detection performance in the periphery

2021 ◽  
Author(s):  
Lisa Valentina Eberhardt ◽  
Christoph Strauch ◽  
Tim Samuel Hartmann ◽  
Anke Huckauf
Keyword(s):  
Visible Light ◽  
Pupil Size ◽  
Signal To Noise Ratio ◽  
Detection Performance ◽  
Eye Tracker ◽  
Signal To Noise ◽  
Current Trial ◽  
Spatial Frequencies ◽  
Online Setting ◽  
Pupillary Change

AbstractVisible light enters our body via the pupil. By changing its size, the pupil shapes visual input. Small apertures increase the resolution of high spatial frequencies, thus allowing discrimination of fine details. Large apertures, in contrast, provide a better signal-to-noise ratio, because more light can enter the eye. This should lead to better detection performance of peripheral stimuli. Experiment 1 shows that the effect can reliably be demonstrated even in a less controlled online setting. In Experiment 2, pupil size was measured in a laboratory using an eye tracker. The findings replicate findings showing that large pupils provide an advantage for peripheral detection of faint stimuli. Moreover, not only pupil size during information intake in the current trial n, but also its interaction with pupil size preceding information intake, i.e., in trial n-1, predicted performance. This suggests that in addition to absolute pupil size, the extent of pupillary change provides a mechanism to modulate perceptual functions. The results are discussed in terms of low-level sensory as well as higher-level arousal-driven changes in stimulus processing.

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