Variability in rainfall information derived from collocated microwave links

2021 ◽  
Author(s):  
Anna Špačková ◽  
Vojtěch Bareš ◽  
Martin Fencl
Keyword(s):  
Electromagnetic Waves ◽  
Rainfall Intensity ◽  
Weather Condition ◽  
Estimation Accuracy ◽  
Response Patterns ◽  
Spatial Coverage ◽  
Telecommunications Network ◽  
Path Lengths ◽  
Point To Point ◽  
The Individual

<p>In the field of hydrology, there is a significant demand for high spatial-temporal resolution of rainfall information that can be met by commercial microwave links (CMLs). CMLs are commonly used as a backhaul of telecommunications network with favourable spatial coverage especially in urbanized areas. CMLs are point-to-point radio connections operating at frequencies where attenuation of electromagnetic waves can be related to the rainfall intensity.</p><p>The ability of CMLs to assess rainfall intensity is determined by hardware parameters and path lengths of CMLs. The CML operates at various frequencies with horizontal or vertical polarization, moreover, link paths have lengths ranging from hundreds of meters up to kilometres. The characteristics of the rainfall needs to be reflected as they have impact on the errors (de Vos et al., 2019). Even collocated CMLs can detect considerably dissimilar rainfall information. To increase effectivity of rainfall information retrieval it is crucial to understand uncertainties arising from diversity of CML characteristics.</p><p>This study evaluates collocated CMLs that are assumed to be affected by the same weather condition. Having identical CML characteristics (as well as the propagations of the signals), it is expected to observe the same response patterns in the attenuated signals. Any disagreement could be caused by random error, sensitivity to the rainfall intensities, and/or hardware reaction to the condition (e.g. sensitivity of the antenna radome to the rainfall splash). Therefore, the role of arrangement of the direction of rainfall field advection and position of the collocated link paths is considered. The magnitude of disagreement between different groups of collocated links could be specified based on their characteristics. Oppositely, for collocated links under the same conditions but with different characteristics, the attributes of the individual CMLs are suspected for the disagreement.</p><p> </p><p>References</p><p>de Vos, L. W., Overeem, A., Leijnse, H., and Uijlenhoet, R. (2019). Rainfall Estimation Accuracy of a Nationwide Instantaneously Sampling Commercial Microwave Link Network: Error Dependency on Known Characteristics. Journal of Atmospheric and Oceanic Technology 36, 7, 1267-1283. https://doi.org/10.1175/JTECH-D-18-0197.1</p><p> </p><p>This study was supported by the project SpraiLINK 20-14151J of the Czech Science Foundation.</p>

Experimental research of indoor navigation system based on broadcast signals

2020 ◽  
Vol 49 (5) ◽  
pp. 49-57
Author(s):  
A. V. Ksendzuk ◽  
E. A. Surmin ◽  
V. V. Kachesov ◽  
S. O. Zhdanov ◽  
K. S. Shakhalov
Keyword(s):  
Navigation System ◽  
Open Space ◽  
Position Estimation ◽  
Indoor Navigation ◽  
Estimation Accuracy ◽  
Satellite Systems ◽  
Indoor Navigation System ◽  
Point To Point ◽  
Navigation Signals ◽  
Navigation Equipment

Results of an experimental study of a local navigation system based on the processing signals from broadcast sources presented. The results of the development of processing algorithms for point-to-point coordinates estimation of the object are presented. The results of the development of algorithms for trajectories estimation are presented. In performed simulation the possibility of obtaining submeter position estimation accuracy in the proposed system is shown. Development results of the navigation module demonstrator are presented. The results of experimental work in difficult navigation conditions, in the presence of shading, reflections and other factors, are presented. It is shown that the developed navigation module allows in the open space near buildings which partially obscuring the satellite systems signals to obtain accuracy higher than the GNSS navigation equipment. In indoor environment in the absence of satellite navigation signals, the developed module shows positioning accuracy not worse than 1.5 meters and provides a measurement rate 1 Hz and better.

Overview of Remaining Useful Life Methodologies

2008 ◽  
Author(s):  
Yogesh G. Bagul ◽  
Ibrahim Zeid ◽  
Sagar V. Kamarthi
Keyword(s):  
Literature Review ◽  
Remaining Useful Life ◽  
Estimation Accuracy ◽  
Operational Cost ◽  
Useful Life ◽  
The Individual

Nowadays, it is imperative for products to function properly each time they are used. If a product fails during its use, it may have disastrous consequences. Estimating remaining useful life (RUL) of a product is a key to prevent such disasters, improve its reliability, provide security and reduce maintenance and operational cost. Naturally, estimation of RUL of a product and develop methodologies for the same is proving an interesting domain for researchers. This paper gives an overview of RUL estimation methodologies applied to various products. It also discusses hybrid methodologies which improve RUL estimation accuracy and overcome limitations of the individual methodologies. As this is an emerging area, these methodologies have been applied to only a handful of products. A list of these products is provided with references. A quantitative metric that measures the relative important characteristic differences among different methodologies is given. This paper concludes with few important points observed during literature review.

Time Estimation Performance Before, during and after Physical Activity

1988 ◽  
Vol 32 (15) ◽  
pp. 985-989 ◽  
Author(s):  
T. Mihaly ◽  
P.A. Hancock ◽  
M. Vercruyssen ◽  
M. Rahimi
Keyword(s):  
Interval Estimation ◽  
Time Estimation ◽  
Cycle Ergometer ◽  
Estimation Accuracy ◽  
Physical Work ◽  
Time Interval ◽  
Individual Subject ◽  
Knowledge Of Results ◽  
The Individual ◽  
Experimental Findings

An experiment is reported which evaluated performance on a 10-sec time interval estimation task before, during and after physical work on cycle ergometer at intensities of 30 and 60% VO2max, as scaled to the individual subject. Results from the eleven subjects tested indicate a significant increase in variability of estimates during exercise compared to non-exercise phases. Such a trend was also seen in the mean of estimates, where subjects significantly underestimated the target interval (10 seconds) during exercise. Subjects also performed more accurately with information feedback than without knowledge of results, but they were still not able to overcome the effects of exercise. As suggested by the experimental findings, decreased estimation accuracy and increased variability can be expected during physical work and is part of a body of evidence which indicates that exercise and its severity has a substantive impact on perceptual and cognitive performance.

scholarly journals Mosaicking Weather Radar Retrievals from an Operational Heterogeneous Network at C and X Band for Precipitation Monitoring in Italian Central Apennines

2022 ◽  
Vol 14 (2) ◽  
pp. 248
Author(s):  
Stefano Barbieri ◽  
Saverio Di Fabio ◽  
Raffaele Lidori ◽  
Francesco L. Rossi ◽  
Frank S. Marzano ◽  
...  
Keyword(s):  
Atmospheric Precipitation ◽  
Weather Radar ◽  
Geographic Area ◽  
Single Frequency ◽  
Estimation Accuracy ◽  
Central Apennines ◽  
Data Set ◽  
Area Of Interest ◽  
Spatial Coverage ◽  
Network Pattern

Meteorological radar networks are suited to remotely provide atmospheric precipitation retrieval over a wide geographic area for severe weather monitoring and near-real-time nowcasting. However, blockage due to buildings, hills, and mountains can hamper the potential of an operational weather radar system. The Abruzzo region in central Italy’s Apennines, whose hydro-geological risks are further enhanced by its complex orography, is monitored by a heterogeneous system of three microwave radars at the C and X bands with different features. This work shows a systematic intercomparison of operational radar mosaicking methods, based on bi-dimensional rainfall products and dealing with both C and X bands as well as single- and dual-polarization systems. The considered mosaicking methods can take into account spatial radar-gauge adjustment as well as different spatial combination approaches. A data set of 16 precipitation events during the years 2018–2020 in the central Apennines is collected (with a total number of 32,750 samples) to show the potentials and limitations of the considered operational mosaicking approaches, using a geospatially-interpolated dense network of regional rain gauges as a benchmark. Results show that the radar-network pattern mosaicking, based on the anisotropic radar-gauge adjustment and spatial averaging of composite data, is better than the conventional maximum-value merging approach. The overall analysis confirms that heterogeneous weather radar mosaicking can overcome the issues of single-frequency fixed radars in mountainous areas, guaranteeing a better spatial coverage and a more uniform rainfall estimation accuracy over the area of interest.

scholarly journals An MEG Study of Picture Naming

1998 ◽  
Vol 10 (5) ◽  
pp. 553-567 ◽  
Author(s):  
Willem J. M. Levelt ◽  
Peter Praamstra ◽  
Antje S. Meyer ◽  
Päivi Helenius ◽  
Riitta Salmelin
Keyword(s):  
Picture Naming ◽  
Time Windows ◽  
Naming Latency ◽  
Cortical Activation ◽  
Response Patterns ◽  
Phonological Encoding ◽  
A Chain ◽  
Wernicke’S Area ◽  
The Individual ◽  
The Right

The purpose of this study was to relate a psycholinguistic processing model of picture naming to the dynamics of cortical activation during picture naming. The activation was recorded from eight Dutch subjects with a whole-head neuromagnetometer. The processing model, based on extensive naming latency studies, is a stage model. In preparing a picture's name, the speaker performs a chain of specific operations. They are, in this order, computing the visual percept, activating an appropriate lexical concept, selecting the target word from the mental lexicon, phonological encoding, phonetic encoding, and initiation of articulation. The time windows for each of these operations are reasonably well known and could be related to the peak activity of dipole sources in the individual magnetic response patterns. The analyses showed a clear progression over these time windows from early occipital activation, via parietal and temporal to frontal activation. The major specific findings were that (1) a region in the left posterior temporal lobe, agreeing with the location of Wernicke's area, showed prominent activation starting about 200 msec after picture onset and peaking at about 350 msec, (i.e., within the stage of phonological encoding), and (2) a consistent activation was found in the right parietal cortex, peaking at about 230 msec after picture onset, thus preceding and partly overlapping with the left temporal response. An interpretation in terms of the management of visual attention is proposed.

Decomposing the Critical Components of Flash Drought Using the Standardized Evaporative Stress Ratio

2021 ◽  
Author(s):  
Jeffrey Basara ◽  
Stuart Edris ◽  
Jordan Christian ◽  
Bradley Illston ◽  
Eric Hunt ◽  
...  
Keyword(s):  
Rocky Mountains ◽  
Stress Ratio ◽  
Individual Case ◽  
The United States ◽  
Rapid Intensification ◽  
The North ◽  
Spatial Coverage ◽  
Regional Reanalysis ◽  
Critical Components ◽  
The Individual

<p>Flash droughts occur rapidly (~1 month timescale) and have produced significant ecological, agricultural, and socioeconomical impacts. Recent advances in our understanding of flash droughts have resulted in methods to identify and quantify flash drought events and overall occurrence. However, while it is generally understood that flash drought consists of two critical components including (1) anomalous, rapid intensification and (2) the subsequent occurrence of drought, little work has been done to quantify the spatial and temporal occurrence of the individual components, their frequency of covariability, and null events. Thus, this study utilized the standardized evaporative stress ratio (SESR) method of flash drought identification applied to the North American Regional Reanalysis NARR) to quantify individual components of flash drought from 1979 – 2019. Individual case studies were examined and the the drought component was assessed using the United States Drought Monitor for 2010 – 2019.   Additionally, the flash component was assessed using results of previous flash drought studies. Further, the correlation coefficient and composite mean difference was calculated between the flash component and flash droughts identified to determine what regions, if any, experienced rapid intensification but did not fall into flash drought. The results yielded that SESR was able to represent the spatial coverage of drought well for regions east of the Rocky Mountains, with mixed success regarding the intensity of the drought events. The flash component tended to agree well with other flash drought studies though some differences existed especially for areas west of the Rocky Mountains which experience rapid intensification at high frequencies but did not achieve drought designations due to hyper-aridity.</p>

Effects of high-intensity cycle exercise on sympathoadrenal-medullary response patterns

1991 ◽  
Vol 70 (1) ◽  
pp. 8-14 ◽  
Author(s):  
W. J. Kraemer ◽  
J. F. Patton ◽  
H. G. Knuttgen ◽  
C. J. Hannan ◽  
T. Kettler ◽  
...  
Keyword(s):  
High Intensity ◽  
Maximal Exercise ◽  
Cycle Ergometer ◽  
Plasma Norepinephrine ◽  
Response Patterns ◽  
O2 Uptake ◽  
Cycle Exercise ◽  
Before And After ◽  
The Mean ◽  
The Individual

Plasma proenkephalin peptide F immunoreactivity and catecholamines were examined on separate days in nine healthy males before and after maximal exercise to exhaustion at four intensities [36, 55, 73, and 100% of maximal leg power (MLP)] by use of a computerized cycle ergometer. The mean duration of 36, 55, 73, and 100% MLP was 3.31, 0.781, 0.270, and 0.1 min, respectively. All intensities were greater than those eliciting peak O2 uptake for the individual subjects. Blood samples were obtained before, immediately after exercise, and 5 and 15 min after exercise. Significant (P less than 0.05) increases in plasma peptide F immunoreactivity (i.e., from mean resting value of 0.18 to 0.43 pmol/ml) were observed immediately after exercise at 36% MLP. Significant increases in plasma epinephrine were observed immediately after exercise at 36% MLP (i.e., from mean resting value of 2.22 to 3.11 pmol/ml) and 55% MLP (i.e., from mean resting value of 1.67 to 2.98 pmol/ml) and 15 min after exercise at 100% MLP (i.e., from mean resting value of 1.92 to 3.88 pmol/ml). Significant increases for plasma norepinephrine were observed immediately after exercise (36, 55, 73, and 100% MLP), 5 min after exercise (36, 55, and 73% MLP), and 15 min after exercise (36% MLP). Increases in whole blood lactate were observed at all points after exercise for 36, 55, and 73% MLP and 5 min after exercise for 100% MLP. These data show that brief high-intensity exercise results in differential response patterns of catecholamines and proenkephalin peptide F immunoreactivity.

scholarly journals Rainfall Estimation Accuracy of a Nationwide Instantaneously Sampling Commercial Microwave Link Network: Error Dependency on Known Characteristics

2019 ◽  
Vol 36 (7) ◽  
pp. 1267-1283 ◽  
Author(s):  
L. W. de Vos ◽  
A. Overeem ◽  
H. Leijnse ◽  
R. Uijlenhoet
Keyword(s):  
Coefficient Of Variation ◽  
Rainfall Intensity ◽  
Sampling Rate ◽  
Early Morning ◽  
Estimation Accuracy ◽  
Signal Attenuation ◽  
Late Night ◽  
Instantaneous Sampling ◽  
Overall Performance ◽  
Microwave Link

AbstractCommercial microwave links are installed and maintained for the purpose of telecommunication. Hydrometeors between transmitting and receiving antennas cause the microwave signal to be attenuated. From signal attenuation, the path-averaged rainfall intensity can be calculated. A 7-month dataset of instantaneously logged signal powers from almost 2000 unique links in the Netherlands is analyzed. Rainfall intensities are calculated with the RAINLINK package with a novel preprocessing module, enabling the package to be applied on instantaneously logged data from now on. Rainfall intensities per link are validated with the path-averaged rainfall intensities according to a gauge-adjusted radar product. Both the overall performance and the dependence of errors on link characteristics and measurement conditions are evaluated. The coefficient of variation decreases from 3.70 to 2.32 and the correlation increases from 0.30 to 0.63 from instantaneous to daily estimates of rainfall accumulations. The coefficient of variation is also smaller during heavy rainfall. Errors are largest for pathlengths shorter than 2 km, for observations during the late night and early morning, and for observations during colder months (when solid or melting precipitation could occur and dew is more likely to form on the antennas). Comparison of our results with those of earlier studies shows that minimum/maximum sampling (widely employed in network management systems) outperforms instantaneous sampling regarding detection of both quantity and occurrence of rain at a 15-min sampling rate in the Dutch climate.

Analysis of the conductivity property of live working shielding clothing

2017 ◽  
Vol 48 (3) ◽  
pp. 643-659 ◽  
Author(s):  
Ying Su ◽  
Xiuchen Wang ◽  
Yaping Li ◽  
Zhen Pan ◽  
Zhe Liu
Keyword(s):  
Electromagnetic Waves ◽  
Structural Complexity ◽  
Measuring Point ◽  
Conductivity Property ◽  
Structure Line ◽  
Design Production ◽  
Point To Point ◽  
Representative Points ◽  
The Relationship ◽  
Resistance Value

Live working shielding clothing must be worn when working under the high-pressure environment. High voltage and electromagnetic waves are shielded by conducting principle, so as to reduce the harm to human body. At present, the relationship between the point to point resistance and the structure of clothing is not clear in the production and research of shielding clothing, its design, production, and test lack of theoretical guidance. In this paper, the electrical conductivity of the clothing is studied by measuring the point to point resistance of shielding clothing. The suitable method of measuring point to point resistance is designed, and test platform is build by U610E's digital multimeter and homemade special electrode and other equipment. The representative points are selected from the main latitude lines of clothing and the parts of contacting electrified equipment when wearing clothes, then measure the resistance value between different points. Through the analysis of the experimental results it can be found that, on the basis of good connection, the farther the distance between two points, the smaller the resistance value and the better the connectivity; the resistance value of the points that frequently contact with electrified equipment is significantly smaller than others; about the same distance of two points, if there is structure line in the middle, the resistance value is large; the structural complexity is proportional to the resistance value. It is concluded that the point to point resistance of shielding garment is related to the parts of contacting with electrified equipment during operation, the complexity of structure, and other relevant factors. In the design and production, we should focus on reducing the resistance value between the most distal of clothing, the parts of contacting electrification equipment and limbs, in order to increase its connectivity; the structural design of clothing should be simplified.

The Warning Decision Support System–Integrated Information

2007 ◽  
Vol 22 (3) ◽  
pp. 596-612 ◽  
Author(s):  
Valliappa Lakshmanan ◽  
Travis Smith ◽  
Gregory Stumpf ◽  
Kurt Hondl
Keyword(s):  
Decision Support ◽  
Decision Support System ◽  
Support System ◽  
Severe Weather ◽  
Weather Data ◽  
Spatial Coverage ◽  
Analysis System ◽  
Automated Algorithms ◽  
The Individual ◽  
Integrated Information

Abstract The Warning Decision Support System–Integrated Information (WDSS-II) is the second generation of a system of tools for the analysis, diagnosis, and visualization of remotely sensed weather data. WDSS-II provides a number of automated algorithms that operate on data from multiple radars to provide information with a greater temporal resolution and better spatial coverage than their currently operational counterparts. The individual automated algorithms that have been developed using the WDSS-II infrastructure together yield a forecasting and analysis system providing real-time products useful in severe weather nowcasting. The purposes of the individual algorithms and their relationships to each other are described, as is the method of dissemination of the created products.

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