scholarly journals Design of Enhanced Rotation Locked Loop for Roll Angle Estimation of Rotating Vehicle in a Weak GPS Signal Environment

Sensors ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 80
Author(s):  
Hun Im ◽  
Deok Lim ◽  
Sang Lee
Keyword(s):  
Computer Simulations ◽  
Signal To Noise Ratio ◽  
Signal Strength ◽  
Roll Angle ◽  
Weak Signal ◽  
Signal To Noise ◽  
Angle Estimation ◽  
Signal Environment ◽  
Noise Ratio

In order to estimate the roll angle of a rotating vehicle, an enhanced rotation locked loop (RLL) algorithm is proposed in this paper. The RLL algorithm estimates the roll angle by using the property that the power of the GPS signal measured at the receiver of a rotating vehicle changes periodically. However, in case the received GPS power is decreased, the performance of the conventional RLL algorithm degrades, or it cannot estimate the roll angle anymore, therefore, for operating the RLL algorithm in a weak signal environment, this paper designs a method to increase the signal-to-noise ratio (SNR) by overlapping multiple GPS signals’ correlator outputs and a method to compensate the decreased response of a rotation discriminator at low-signal strength. Through computer simulations, the performance of the proposed algorithm is verified and it is shown that the roll angle can be estimated stably even at a weak signal environment down to 29 dB–Hz of C/N0.

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

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 Weak Signal Extraction from Lunar Penetrating Radar Channel 1 Data Based on Local Correlation

Electronics ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 573 ◽  
Author(s):  
Zhuo Jia ◽  
Sixin Liu ◽  
Ling Zhang ◽  
Bin Hu ◽  
Jianmin Zhang
Keyword(s):  
Signal To Noise Ratio ◽  
Lunar Regolith ◽  
Signal Extraction ◽  
Weak Signal ◽  
Human Beings ◽  
Subsurface Structure ◽  
Local Correlation ◽  
Signal To Noise ◽  
Near Surface ◽  
Noise Ratio

Knowledge of the subsurface structure not only provides useful information on lunar geology, but it also can quantify the potential lunar resources for human beings. The dual-frequency lunar penetrating radar (LPR) aboard the Yutu rover offers a Special opportunity to understand the subsurface structure to a depth of several hundreds of meters using a low-frequency channel (channel 1), as well as layer near-surface stratigraphic structure of the regolith using high-frequency observations (channel 2). The channel 1 data of the LPR has a very low signal-to-noise ratio. However, the extraction of weak signals from the data represents a problem worth exploring. In this article, we propose a weak signal extraction method in view of local correlation to analyze the LPR CH-1 data, to facilitate a study of the lunar regolith structure. First, we build a pre-processing workflow to increase the signal-to-noise ratio (SNR). Second, we apply the K-L transform to separate the horizontal signal and then use the seislet transform (ST) to reserve the continuous signal. Then, the local correlation map is calculated using the two denoising results and a time–space dependent weighting operator is constructed to suppress the noise residuals. The weak signal after noise suppression may provide a new reference for subsequent data interpretation. Finally, in combination with the regional geology and previous research, we provide some speculative interpretations of the LPR CH-1 data.

Automatic detection of bioacoustics impulses based on kurtosis under weak signal to noise ratio

2010 ◽  
Vol 71 (11) ◽  
pp. 1020-1026 ◽  
Author(s):  
C. Gervaise ◽  
A. Barazzutti ◽  
S. Busson ◽  
Y. Simard ◽  
N. Roy
Keyword(s):  
Signal To Noise Ratio ◽  
Automatic Detection ◽  
Weak Signal ◽  
Signal To Noise ◽  
Noise Ratio

Determination of the Best Emulsion for the Microscopy of Crystals

1981 ◽  
Vol 39 ◽  
pp. 32-33
Author(s):  
David A. Grano ◽  
Kenneth H. Downing
Keyword(s):  
Spatial Frequency ◽  
Information Transfer ◽  
Signal To Noise Ratio ◽  
Experimental Situation ◽  
Photographic Emulsion ◽  
Modulation Transfer ◽  
Signal To Noise ◽  
Frequency Space ◽  
Noise Ratio

The retrieval of high-resolution information from images of biological crystals depends, in part, on the use of the correct photographic emulsion. We have been investigating the information transfer properties of twelve emulsions with a view toward 1) characterizing the emulsions by a few, measurable quantities, and 2) identifying the “best” emulsion of those we have studied for use in any given experimental situation. Because our interests lie in the examination of crystalline specimens, we've chosen to evaluate an emulsion's signal-to-noise ratio (SNR) as a function of spatial frequency and use this as our critereon for determining the best emulsion.The signal-to-noise ratio in frequency space depends on several factors. First, the signal depends on the speed of the emulsion and its modulation transfer function (MTF). By procedures outlined in, MTF's have been found for all the emulsions tested and can be fit by an analytic expression 1/(1+(S/S0)2). Figure 1 shows the experimental data and fitted curve for an emulsion with a better than average MTF. A single parameter, the spatial frequency at which the transfer falls to 50% (S0), characterizes this curve.

Experiments in Bright-Field Imaging with Hollow-Cone Illumination

1981 ◽  
Vol 39 ◽  
pp. 226-227
Author(s):  
W. Kunath ◽  
K. Weiss ◽  
E. Zeitler
Keyword(s):  
Signal To Noise Ratio ◽  
Carbon Support ◽  
Electronic System ◽  
Optic Axis ◽  
Hollow Cone ◽  
Signal To Noise ◽  
Bright Field ◽  
Noise Ratio ◽  
Single Field ◽  
Field Imaging

Bright-field images taken with axial illumination show spurious high contrast patterns which obscure details smaller than 15 ° Hollow-cone illumination (HCI), however, reduces this disturbing granulation by statistical superposition and thus improves the signal-to-noise ratio. In this presentation we report on experiments aimed at selecting the proper amount of tilt and defocus for improvement of the signal-to-noise ratio by means of direct observation of the electron images on a TV monitor.Hollow-cone illumination is implemented in our microscope (single field condenser objective, Cs = .5 mm) by an electronic system which rotates the tilted beam about the optic axis. At low rates of revolution (one turn per second or so) a circular motion of the usual granulation in the image of a carbon support film can be observed on the TV monitor. The size of the granular structures and the radius of their orbits depend on both the conical tilt and defocus.

Information capacity and bandwidth limitations in the SEM

1989 ◽  
Vol 47 ◽  
pp. 84-85
Author(s):  
D. C. Joy ◽  
R. D. Bunn
Keyword(s):  
Signal To Noise Ratio ◽  
Critical Dimension ◽  
Information Capacity ◽  
Acquisition Time ◽  
Signal To Noise ◽  
Sem Image ◽  
Probe Size ◽  
Minimum Number ◽  
Noise Ratio ◽  
Signal Channel

The information available from an SEM image is limited both by the inherent signal to noise ratio that characterizes the image and as a result of the transformations that it may undergo as it is passed through the amplifying circuits of the instrument. In applications such as Critical Dimension Metrology it is necessary to be able to quantify these limitations in order to be able to assess the likely precision of any measurement made with the microscope.The information capacity of an SEM signal, defined as the minimum number of bits needed to encode the output signal, depends on the signal to noise ratio of the image - which in turn depends on the probe size and source brightness and acquisition time per pixel - and on the efficiency of the specimen in producing the signal that is being observed. A detailed analysis of the secondary electron case shows that the information capacity C (bits/pixel) of the SEM signal channel could be written as :

Speech Reception in the Presence of Classroom Noise

1979 ◽  
Vol 10 (4) ◽  
pp. 221-230 ◽  
Author(s):  
Veronica Smyth
Keyword(s):  
Signal To Noise Ratio ◽  
Learning Processes ◽  
Speech Discrimination ◽  
Signal To Noise ◽  
Speech Reception ◽  
Monosyllabic Words ◽  
Noise Ratio

Three hundred children from five to 12 years of age were required to discriminate simple, familiar, monosyllabic words under two conditions: 1) quiet, and 2) in the presence of background classroom noise. Of the sample, 45.3% made errors in speech discrimination in the presence of background classroom noise. The effect was most marked in children younger than seven years six months. The results are discussed considering the signal-to-noise ratio and the possible effects of unwanted classroom noise on learning processes.

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