To see the other types of publications on this topic, follow the link: Radar operators.
Journal articles on the topic 'Radar operators'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Radar operators.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Ryzhkov, Alexander V., Jeffrey Snyder, Jacob T. Carlin, Alexander Khain, and Mark Pinsky. "What Polarimetric Weather Radars Offer to Cloud Modelers: Forward Radar Operators and Microphysical/Thermodynamic Retrievals." Atmosphere 11, no. 4 (April 8, 2020): 362. http://dx.doi.org/10.3390/atmos11040362.
Full textAbstract:
The utilization of polarimetric weather radars for optimizing cloud models is a next frontier of research. It is widely understood that inadequacies in microphysical parameterization schemes in numerical weather prediction (NWP) models is a primary cause of forecast uncertainties. Due to its ability to distinguish between hydrometeors with different microphysical habits and to identify “polarimetric fingerprints” of various microphysical processes, polarimetric radar emerges as a primary source of needed information. There are two approaches to leverage this information for NWP models: (1) radar microphysical and thermodynamic retrievals and (2) forward radar operators for converting the model outputs into the fields of polarimetric radar variables. In this paper, we will provide an overview of both. Polarimetric measurements can be combined with cloud models of varying complexity, including ones with bulk and spectral bin microphysics, as well as simplified Lagrangian models focused on a particular microphysical process. Combining polarimetric measurements with cloud modeling can reveal the impact of important microphysical agents such as aerosols or supercooled cloud water invisible to the radar on cloud and precipitation formation. Some pertinent results obtained from models with spectral bin microphysics, including the Hebrew University cloud model (HUCM) and 1D models of melting hail and snow coupled with the NSSL forward radar operator, are illustrated in the paper.
2
Дудуш, А. С., І. І. Сачук, Сальман Оваід, and А. К. Бідун. "Science & technology trends in cognitive radar concept." Системи обробки інформації, no. 3(166) (September 24, 2021): 22–34. http://dx.doi.org/10.30748/soi.2021.166.02.
Full textAbstract:
Currently, human operators provide cognition in a radar system. However, advances in the “digitization” of radar front-ends, including digital arbitrary waveform generators (AWG) and advanced high performance embedded computing (HPEC) make it possible to vary all key radar parameters (power, pulse length, number of pulses, pulse repetition frequency (PRF), modulation, frequency, polarization) on a pulse-by-pulse basis within ns or ms and over a wide operating range. This timescale is much faster than the decision-making ability of a human operator. The cognitive-inspired techniques in radar, that are intensively developing last years, mimic elements of human cognition and the use of external knowledge to use the available system resources in an optimal way for the current goal and environment. Radar systems based on the perception-action cycle of cognition that senses the environment, learns relevant information from it about the target and the background and then adapts the radar to optimally satisfy the needs of the mission according to a desired goal are called cognitive radars. In the article, recent ideas and applications of cognitive radars were analyzed.
3
Zhang, Guifu, Jidong Gao, and Muyun Du. "Parameterized Forward Operators for Simulation and Assimilation of Polarimetric Radar Data with Numerical Weather Predictions." Advances in Atmospheric Sciences 38, no. 5 (April 8, 2021): 737–54. http://dx.doi.org/10.1007/s00376-021-0289-6.
Full textAbstract:
AbstractMany weather radar networks in the world have now provided polarimetric radar data (PRD) that have the potential to improve our understanding of cloud and precipitation microphysics, and numerical weather prediction (NWP). To realize this potential, an accurate and efficient set of polarimetric observation operators are needed to simulate and assimilate the PRD with an NWP model for an accurate analysis of the model state variables. For this purpose, a set of parameterized observation operators are developed to simulate and assimilate polarimetric radar data from NWP model-predicted hydrometeor mixing ratios and number concentrations of rain, snow, hail, and graupel. The polarimetric radar variables are calculated based on the T-matrix calculation of wave scattering and integrations of the scattering weighted by the particle size distribution. The calculated polarimetric variables are then fitted to simple functions of water content and volume-weighted mean diameter of the hydrometeor particle size distribution. The parameterized PRD operators are applied to an ideal case and a real case predicted by the Weather Research and Forecasting (WRF) model to have simulated PRD, which are compared with existing operators and real observations to show their validity and applicability. The new PRD operators use less than one percent of the computing time of the old operators to complete the same simulations, making it efficient in PRD simulation and assimilation usage.
4
Mahale, Vivek N., Guifu Zhang, Ming Xue, Jidong Gao, and Heather D. Reeves. "Variational Retrieval of Rain Microphysics and Related Parameters from Polarimetric Radar Data with a Parameterized Operator." Journal of Atmospheric and Oceanic Technology 36, no. 12 (December 1, 2019): 2483–500. http://dx.doi.org/10.1175/jtech-d-18-0212.1.
Full textAbstract:
Abstract A variational retrieval of rain microphysics from polarimetric radar data (PRD) has been developed through the use of S-band parameterized polarimetric observation operators. Polarimetric observations allow for the optimal retrieval of cloud and precipitation microphysics for weather quantification and data assimilation for convective-scale numerical weather prediction (NWP) by linking PRD to physical parameters. Rain polarimetric observation operators for reflectivity ZH, differential reflectivity ZDR, and specific differential phase KDP were derived for S-band PRD using T-matrix scattering amplitudes. These observation operators link the PRD to the physical parameters of water content W and mass-/volume-weighted diameter Dm for rain, which can be used to calculate other microphysical information. The S-band observation operators were tested using a 1D variational retrieval that uses the (nonlinear) Gauss–Newton method to iteratively minimize the cost function to find an optimal estimate of Dm and W separately for each azimuth of radar data, which can be applied to a plan position indicator (PPI) radar scan (i.e., a single elevation). Experiments on two-dimensional video disdrometer (2DVD) data demonstrated the advantages of including ΦDP observations and using the nonlinear solution rather than the (linear) optimal interpolation (OI) solution. PRD collected by the Norman, Oklahoma (KOUN) WSR-88D on 15 June 2011 were used to successfully test the retrieval method on radar data. The successful variational retrieval from the 2DVD and the radar data demonstrate the utility of the proposed method.
5
Goh, Y. K., A. R. Holt, and P. P. Alberoni. "Doppler radar wind field retrieval over the Po Valley." Natural Hazards and Earth System Sciences 6, no. 2 (May 4, 2006): 285–91. http://dx.doi.org/10.5194/nhess-6-285-2006.
Full textAbstract:
Abstract. Although methods of using multiple Doppler radars to study wind fields have long been proposed, and many research studies have been made, very few operational radar operators adopt methods which require the use of specific scanning strategies to allow the extraction of wind information. Here we report a collaborative study on dual-Doppler radars based on two Doppler radars in the Po valley, Italy. Unusually, the radars are only about 90 km apart, though operated by the same authority. The wind field syntheses are carried out on a 30 km by 30 km region where the two radars have overlapping scan coverage. An iterative method based on the linear wind model and the equation of mass continuity is used to construct the wind fields. The methodology has been validated by two different methods. The first method is to reconstruct the radial wind observed by each radar, and the second method is calculating and comparing the along-track component with that derived from the observations. Both two comparisons show good agreement with the original data.
6
Beyea, Jan, Bernd Franke, and Melvin Siedband. "X-ray doses from radar received by Belgian professional military radar operators." International Journal of Cancer 134, no. 12 (December 6, 2013): 2995–96. http://dx.doi.org/10.1002/ijc.28635.
Full text
7
Burgers, Travis A., and Kelly J. Vanderwerff. "Vision and Radar Steering Reduces Agricultural Sprayer Operator Stress without Compromising Steering Performance." Journal of Agricultural Safety and Health 28, no. 3 (2022): 163–79. http://dx.doi.org/10.13031/jash.15060.
Full textAbstract:
HighlightsStress was measured in professional sprayer operators who, while working, drove manually and with vision or radar steering.Vision and radar steering reduced the average operator stress rate by 48% relative to manual steering.The use of automatic guidance could have a dramatic positive effect on the health of sprayer operators.Sprayer steering performance was reported for professional operators and both vision and radar guidance for the first time.Abstract. Self-propelled agricultural sprayer operators work an average of 15 h d-1 in peak season, and steering is the task that causes the operator the most stress because of the large number of stimuli involved. Automatic guidance systems help reduce stress and fatigue for operators by allowing them to focus on tasks other than steering. Physiological signals like skin conductance (electrodermal activity, EDA) change with stress and can be used to identify stressful events. The objective of this study was to determine if using a commercially available vision and radar guidance system (VSN®, Raven Industries) reduces agricultural sprayer operators’ stress compared to when they are steering manually. Four male professional sprayer operators participated in this study. Each operator performed his job duties normally in GPS-guidance-planted fields, at his self-selected speed, except to drive some passes manually and others with VSN in the same field. EDA was measured with an Empatica E4 wristband, and stressful events were quantified. Machine data (e.g., speed, RTK-GPS, and VSN metrics) were collected from each sprayer via CAN logs. The steering type, stress rate (e.g., stressful events min-1), and steering performance (cross-track error standard deviation, XTE SD) were determined for each pass. In total, 51 passes (23 manual, 28 VSN) in six fields were analyzed. Operators using VSN had a significant reduction (48% lower, p < 0.001) in their stress rate compared to when they were steering manually. There was no significant difference in the XTE SD for the steering type. The use of an automatic guidance system such as VSN could have a dramatic positive effect on the health of sprayer operators, especially during the long workdays of the peak spraying season, and could reduce the negative effects that stress and fatigue have on steering performance, mistakes, and accidents. Keywords: Electrodermal activity, Guidance systems, Machine vision, Precision agriculture, Radar, Skin conductance, Vehicle guidance.
8
Blahak, Ulrich. "An Approximation to the Effective Beam Weighting Function for Scanning Meteorological Radars with an Axisymmetric Antenna Pattern." Journal of Atmospheric and Oceanic Technology 25, no. 7 (July 1, 2008): 1182–96. http://dx.doi.org/10.1175/2007jtecha1010.1.
Full textAbstract:
Abstract To obtain statistically stable reflectivity measurements by meteorological radars, it is common practice to average over several consecutive pulses during which the antenna rotates at a certain angular velocity. Taking into account the antenna’s continuous motion, the measured reflectivity is determined by an effective beam weighting function, which is different from a single-pulse weighting function—a fact that is widely ignored in applications involving beam weighting. In this paper, the effective beam weighting function is investigated in detail. The theoretical derivation shows that the effective weighting function is essentially a simple moving sum of single-beam weighting functions. Assuming a Gaussian shape of a single pulse, a simple and easy-to-use parameterization of the effective beam weighting function is arrived at, which depends only on the single beamwidth and the ratio of the single beamwidth to the rotational angular averaging interval. The derived relation is formulated in the “radar system” (i.e., the spherical coordinate system consisting of azimuth and elevation angles) that is often applied in practice. Formulas for the “beam system” (two orthogonal angles relative to the beam axis) are also presented. The final parameterization should be applicable to almost all meteorological radars and might be used (i) in specialized radar data analyses (with ground-based or satellite radars) and (ii) for radar forward operators to calculate simulated radar parameters from the results of NWP models.
9
Kawabata, Takuya, Thomas Schwitalla, Ahoro Adachi, Hans-Stefan Bauer, Volker Wulfmeyer, Nobuhiro Nagumo, and Hiroshi Yamauchi. "Observational operators for dual polarimetric radars in variational data assimilation systems (PolRad VAR v1.0)." Geoscientific Model Development 11, no. 6 (June 22, 2018): 2493–501. http://dx.doi.org/10.5194/gmd-11-2493-2018.
Full textAbstract:
Abstract. We implemented two observational operators for dual polarimetric radars in two variational data assimilation systems: WRF Var, the Weather Research and Forecasting Model variational data assimilation system, and NHM-4DVAR, the nonhydrostatic variational data assimilation system for the Japan Meteorological Agency nonhydrostatic model. The operators consist of a space interpolator, two types of variable converters, and their linearized and transposed (adjoint) operators. The space interpolator takes account of the effects of radar-beam broadening in both the vertical and horizontal directions and climatological beam bending. The first variable converter emulates polarimetric parameters with model prognostic variables and includes attenuation effects, and the second one derives rainwater content from the observed polarimetric parameter (specific differential phase). We developed linearized and adjoint operators for the space interpolator and variable converters and then assessed whether the linearity of the linearized operators and the accuracy of the adjoint operators were good enough for implementation in variational systems. The results of a simple assimilation experiment showed good agreement between assimilation results and observations with respect to reflectivity and specific differential phase but not with respect to differential reflectivity.
10
Fox, Elizabeth, Arielle Stephenson, Christopher Stevens, and Gregory Bowers. "Predictors of Human Efficiency in Radar Detection Tasks." International Conference on Cyber Warfare and Security 18, no. 1 (February 28, 2023): 93–102. http://dx.doi.org/10.34190/iccws.18.1.976.
Full textAbstract:
Aegis operators simultaneously locate and monitor the activity of several hostile targets, intervening and alerting their team when appropriate. Utilizing the Aegis Combat System, operators find, track, and respond to dynamic targets on a radar screen. The demand that operators undergo is often high, inevitably causing strain on cognitive functions and detriments to performance. We applied model-based measures, Cost and Multitasking Throughput, to quantify the influence of external factors on processing efficiency in radar task(s). We captured the influence of three experimental manipulations, each of three levels, on human efficiency to track the location of hostiles and/or detect brief radar interference. We collected participants’ performance to complete a multiple object tracking (MOT) task and an electronic attack detection task (EA) using a radar display. A factorial manipulation of conditions comprised changes to task(s) (EA, MOT, or both), the number of targets to track (2, 4, or 6) and the presence or absence of distractors, deemed 'friendlies' (between 500-1000 total tracks). Our novel individual- and model-based approach provided quantitative estimates of human efficiency. We compared the observed variation in efficiency among predictors including target quantity, visual load, and the presence of one or two interrelated tasks. Through quantifying the relationship of these variables to radar detection tasks, we discuss implications of our findings and provide a framework to examine how system designers may develop tools to alleviate observed cognitive demands and/or counter potential threats of electronic attacks in radar detection and tracking tasks.
11
Potapov, Alexander A. "Mathematical Foundations of the Fractal Scaling Method in Statistical Radiophysics and Applications." Radioelectronics. Nanosystems. Information Technologies. 13, no. 3 (September 30, 2021): 245–96. http://dx.doi.org/10.17725/rensit.2021.13.245.
Full textAbstract:
The system of basic mathematical concepts and constructions underlying the modern global fractal-scaling method developed by the author is presented. An overview of the main results on the creation of new information technologies based on textures, fractals (multifractals), fractional operators, scaling effects and nonlinear dynamics methods obtained by the author and his students for more than 40 years (from 1979 to the present) at the V.A. Kotelnikov Institute of Radioengineering and Electronics of RAS. It is shown that, for the first time in the world, new dimensional and topological (and not energy!) Features or invariants were proposed and then effectively applied for problems in radio physics and radio electronics, which are combined under the generalized concept of "sample topology" ~ "fractal signature". The author discovered, proposed and substantiated a new type and new method of modern radar, namely, fractal-scaling or scale-invariant radar. It should be noted that fractal radars are, in fact, a necessary intermediate stage on the path of transition to cognitive radar and quantum radar.
12
Fisher, P. D. "Microwave exposure levels encountered by police traffic radar operators." IEEE Transactions on Electromagnetic Compatibility 35, no. 1 (1993): 36–45. http://dx.doi.org/10.1109/15.249394.
Full text
13
Oleksenko, Oleksandr, Hennadii Khudov, Kyrylo Petrenko, Yurii Horobets, Valerii Kolianda, Nina Kuchuk, Andrij Konstantinov, et al. "The Development of the Method of Radar Observation System Construction of the Airspace on the Basis of Genetic Algorithm." International Journal of Emerging Technology and Advanced Engineering 11, no. 8 (August 19, 2021): 23–30. http://dx.doi.org/10.46338/ijetae0821_04.
Full textAbstract:
The methodological approaches to the use of genetic algorithm for the synthesis of the rational structure of the radar surveillance system are proposed in the paper. The structure of the radar surveillance system is presented in the form of an incidence matrix, which is used as a chromosome by the operators of the genetic algorithm. This matrix is used as a chromosome by the operators of the genetic algorithm. The elements of the incidence matrix that describe the relationships between the elements of the structure of the observation system are genes in the genetic algorithm. In each cycle of the genetic algorithm, a pair of chromosomes is paired, during which part of the genes are exchanged, which for the system under study means the appearance and disappearance of the corresponding connections between the elements. The calculation of the values of the efficiency of radar surveillance for each variant of the structure is proposed to be carried out using the ant colony optimization. The gain in the value of the conditional probability of correct detection with a fixed probability of false alarm is approximately 10% Keywords— genetic algorithm, artificial intelligence, optimization, route, radar surveillance system.
14
Gupta, Khushi, Soumya Joshi, M. B. Srinivas, Srinivas Boppu, M. Sabarimalai Manikandan, and Linga Reddy Cenkeramaddi. "Localization of Multi-Class On-Road and Aerial Targets Using mmWave FMCW Radar." Electronics 10, no. 23 (November 24, 2021): 2905. http://dx.doi.org/10.3390/electronics10232905.
Full textAbstract:
mmWave radars play a vital role in autonomous systems, such as unmanned aerial vehicles (UAVs), unmanned surface vehicles (USVs), ground station control and monitoring systems. The challenging task when using mmWave radars is to estimate the accurate angle of arrival (AoA) of the targets, due to the limited number of receivers. In this paper, we present a novel AoA estimation technique, using mmWave FMCW radars operating in the frequency range 77–81 GHz by utilizing the mechanical rotation. Rotating the radar also increases the field of view in both azimuth and elevation. The proposed method estimates the AoA of the targets, using only a single transmitter and receiver. The measurements are carried out in a variety of practical scenarios including pedestrians, a car, and an UAV, also known as a drone. With measured data, range-angle maps are created, and morphological operators are used to estimate the AoA of the targets. We also process radar range-angle images for improved visual representation. The proposed method will be extremely beneficial for practical ground stations, traffic control and monitoring frameworks for both on-ground and airborne vehicles.
15
Kostyria, O. O., A. A. Hryzo, О. M. Dodukh, І. М. Nevmerzhytskyi, O. A. Nahorniuk, and V. M. Miniailo. "RESULTS OF EXPERIMENTAL RESEARCH OF MULTI-BAND SIMULATOR OF THE MANUFACTURER OF ACTIVE NOISE JAMMER." Проблеми створення, випробування, застосування та експлуатації складних інформаційних систем, no. 22 (August 4, 2022): 41–54. http://dx.doi.org/10.46972/2076-1546.2022.22.04.
Full textAbstract:
The article provides information on the results of experimental studies of a multi-band hardware and software complex for simulating the action of an active noise jammer, which has been created for the training of operators of radar stations of radio engineering troops. One of the important elements of the professional training of the radar stations operators of the air defense radio engineering forces is their ability to work in difficult target and jamming conditions. The existing simulators for training operators do not fully meet the requirements of the quality of training, since they form only secondary bearing marks on the jammer manufacturer and do not reproduce the situation of deterioration of target detection conditions as a result of the simultaneous action of active and passive noise jammer, as well as the influence of the autocompensator of jammer on the quality of the radar, as it happens in real situation. The offered device for simulating the influence of active jammer has been built according to the modular principle and implemented using software-defined radio technology, which allows to quickly change both the type of signal and its parameters. Power amplifiers and antenna systems have been designed to operate in the 140–190 MHz, 470–900 MHz, and 2500–3500 MHz bands, and for experimental research radar stations in the meter, decimeter, and centimeter wave ranges have been involved. The method of using the simulator has been substantiated, and the conducted studies showed that for radar stations in which the angular beams of the directional pattern have different operating frequencies, there is an additional possibility of simulating the action of the active jammer by changing the frequency of the jammer in the case of operation of the complex directly near the suppression object, where the directional pattern of the radar station antenna has not yet been formed. The method of using the complex both for training sessions and during tactical exercises of the radio technical troops unit to simulate the action of an air-based jamming device or a dropped jamming transmitter has been substantiated. Keywords: active noise jammer; simulation; hardware and software complex; radar station; programmed radio.
16
Wawruch, Ryszard, Jarosław Cydejko, and Marek Dziewicki. "Testing the Quality of Information on Tracked Vessels in a VTS Centre with GNSS." Journal of Navigation 52, no. 2 (May 1999): 252–58. http://dx.doi.org/10.1017/s0373463399008310.
Full textAbstract:
This paper describes selective tests performed in the areas of Gdansk and Gdynia VTS Centres. The main goal of the tests was to determine the accuracy of position, speed and course estimations measured by shore-based radar VTS tracking systems by using measurements of the same parameters available on board a tracked vessel equipped with GPS and GLONASS receivers. Six DGPS/GPS/GLONASS receivers were installed on board a survey vessel, and all of them recorded the vessel's route simultaneously with two different VTS radars – one at Gdansk and one at Gdynia (20 km apart). All DGPS receivers tracked the same reference station. Presented results show that the radar information can be used by VTS operators to provide navigation assistance within certain limits, but these limits must be understood. A more detailed description of the experiment was presented during the IALA Conference in Hamburg in June 1998.
17
Liu, Chang, Ruslan Antypenko, Iryna Sushko, Oksana Zakharchenko, and Ji Wang. "Marine Distributed Radar Signal Identification and Classification Based on Deep Learning." Traitement du Signal 38, no. 5 (October 31, 2021): 1541–48. http://dx.doi.org/10.18280/ts.380531.
Full textAbstract:
Distributed radar is applied extensively in marine environment monitoring. In the early days, the radar signals are identified inefficiently by operators. It is promising to replace manual radar signal identification with machine learning technique. However, the existing deep learning neural networks for radar signal identification consume a long time, owing to autonomous learning. Besides, the training of such networks requires lots of reliable time-frequency features of radar signals. This paper mainly analyzes the identification and classification of marine distributed radar signals with an improved deep neural network. Firstly, the time frequency features were extracted from signals based on short-time Fourier transform (STFT) theory. Then, a target detection algorithm was proposed, which weighs and fuses the heterogenous marine distributed radar signals, and four methods were provided for weight calculation. After that, the frequency-domain priori model feature assistive training was introduced to train the traditional deep convolutional neural network (DCNN), producing a CNN with feature splicing operation. The features of time- and frequency-domain signals were combined, laying the basis for radar signal classification. Our model was proved effective through experiments.
18
Corchia, Timothée, Bertrand Bonan, Nemesio Rodríguez-Fernández, Gabriel Colas, and Jean-Christophe Calvet. "Assimilation of ASCAT Radar Backscatter Coefficients over Southwestern France." Remote Sensing 15, no. 17 (August 30, 2023): 4258. http://dx.doi.org/10.3390/rs15174258.
Full textAbstract:
In this work, Advanced SCATterometer (ASCAT) backscatter data are directly assimilated into the interactions between soil, biosphere, and atmosphere (ISBA) land surface model using Meteo-France’s global Land Data Assimilation System (LDAS-Monde) tool in order to jointly analyse soil moisture and leaf area index (LAI). For the first time, observation operators based on neural networks (NNs) are trained with ISBA simulations and LAI observations from the PROBA-V satellite to predict the ASCAT backscatter signal. The trained NN-based observation operators are implemented in LDAS-Monde, which allows the sequential assimilation of backscatter observations. The impact of the assimilation is evaluated over southwestern France. The simulated and analysed backscatter signal, surface soil moisture, and LAI are evaluated using satellite observations from ASCAT and PROBA-V as well as in situ soil moisture observations. An overall improvement in the variables is observed when comparing the analysis with the open-loop simulation. The impact of the assimilation is greater over agricultural areas.
19
Ge, Guoqing, Jidong Gao, Keith Brewster, and Ming Xue. "Impacts of Beam Broadening and Earth Curvature on Storm-Scale 3D Variational Data Assimilation of Radial Velocity with Two Doppler Radars." Journal of Atmospheric and Oceanic Technology 27, no. 4 (April 1, 2010): 617–36. http://dx.doi.org/10.1175/2009jtecha1359.1.
Full textAbstract:
Abstract The radar ray path and beam broadening equations are important for assimilation of radar data into numerical weather prediction (NWP) models. They can be used to determine the physical location of each radar measurement and to properly map the atmospheric state variables from the model grid to the radar measurement space as part of the forward observation operators. Historically, different degrees of approximations have been made with these equations; however, no systematic evaluation of their impact exists, at least in the context of variational data assimilation. This study examines the effects of simplifying ray path and ray broadening calculations on the radar data assimilation in a 3D variational data assimilation (3DVAR) system. Several groups of Observational System Simulation Experiments (OSSEs) are performed to test the impact of these equations to radar data assimilation with an idealized tornadic thunderstorm case. This study shows that the errors caused by simplifications vary with the distance between the analyzed storm and the radar. For single time level wind analysis, as the surface range increases, the impact of beam broadening on analyzed wind field becomes evident and can cause relatively large error for distances beyond 150 km. The impact of the earth’s curvature is more significant, even for distances beyond 60 km, because it places the data at the wrong vertical location. The impact of refractive index gradient is also tested. It is shown that the variations of refractive index gradient have a very small impact on the wind analysis results. Two time series of 1-h-long data assimilation experiments are further conducted to illustrate the impact of the beam broadening and earth curvature on all retrieved model variables. It is shown that all model variables can be retrieved to some degrees in all data assimilation experiments. Similar to the wind analysis experiments, the impacts of both factors are not obvious when radars are relatively close to the storm. When the radars are far from the storm (especially beyond 150 km), overlooking beam broadening degrades the accuracy of assimilation results slightly, whereas ignoring the earth’s curvature leads to significant errors.
20
Anastasi, Donna, Diane Miller, and Ann-Marie T. Lind. "Team CTA Applied to Radar Operations System Modernization." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 42, no. 3 (October 1998): 210–14. http://dx.doi.org/10.1177/154193129804200306.
Full textAbstract:
A team Cognitive Task Analysis (CTA) approach has been applied to the modernization of a radar operations system. With the remoting and automation of radar operations, there will be dramatic changes in the number and role of operators, as well as the displays required to support operators during missions. To design the new modernized system it is necessary to obtain a full understanding of how the current system operates and ensure that the allocation of tasks to humans and automation fully covers the entire operation. Traditional task analysis does not take into consideration plans for staffing reduction and addition of the new team “member” or agent, i.e., the automated system. To facilitate operator interaction with the modernized system, a new team architecture must be considered. CTA documents current operations, including a representation of mental activities, e.g., assessments, judgements, and decisions, in addition to the physical actions, e.g., executing system commands. A team CTA method is used to model the operations independent of the current operator roles and team structure. This approach captures the element of “team” by assuming a meta-operator and representing parallel tasking and data flow among tasks. This paper provides a description of the team CTA method and its application to large-scale, complex system design.
21
Czaplewski, Krzysztof, Sambor Guze, and Sławomir Świerczyński. "The Impact of Radar Distance Measurement Accuracy on the Accuracy of Position Fixing in VTS Systems." Polish Maritime Research 25, no. 3 (September 1, 2018): 5–13. http://dx.doi.org/10.2478/pomr-2018-0091.
Full textAbstract:
Abstract The main source of information on the situation across the sea basins used by operators of shipping monitoring systems is a network of coastal radar stations. Presently, it is possible to gather navigational information from many individual radar stations simultaneously, which may be used for improving the accuracy of vessel position fixing. However, without making other estimates, we obtain an inconsistent image comprising multiple echoes of the same ship, and as such it is impossible to say which echo presents the vessel on the move. Another problem is the method of performing radar observations, which significantly affects the accuracy of position fixing. The estimated radar distance is encumbered with a gross error in the case of large vessels, as the position of a large vessel is not the same as the position of the edge of the radar echo to which the estimation is made. In this paper, the authors present a method to adjust the measured radar distance. The proposed method may be automated easily, which would significantly enhance VTS positioning processes.
22
Ordonez-Lucena, Jose, Pablo Ameigeiras, Luis M. Contreras, Jesús Folgueira, and Diego R. López. "On the Rollout of Network Slicing in Carrier Networks: A Technology Radar." Sensors 21, no. 23 (December 3, 2021): 8094. http://dx.doi.org/10.3390/s21238094.
Full textAbstract:
Network slicing is a powerful paradigm for network operators to support use cases with widely diverse requirements atop a common infrastructure. As 5G standards are completed, and commercial solutions mature, operators need to start thinking about how to integrate network slicing capabilities in their assets, so that customer-facing solutions can be made available in their portfolio. This integration is, however, not an easy task, due to the heterogeneity of assets that typically exist in carrier networks. In this regard, 5G commercial networks may consist of a number of domains, each with a different technological pace, and built out of products from multiple vendors, including legacy network devices and functions. These multi-technology, multi-vendor and brownfield features constitute a challenge for the operator, which is required to deploy and operate slices across all these domains in order to satisfy the end-to-end nature of the services hosted by these slices. In this context, the only realistic option for operators is to introduce slicing capabilities progressively, following a phased approach in their roll-out. The purpose of this paper is to precisely help designing this kind of plan, by means of a technology radar. The radar identifies a set of solutions enabling network slicing on the individual domains, and classifies these solutions into four rings, each corresponding to a different timeline: (i) as-is ring, covering today’s slicing solutions; (ii) deploy ring, corresponding to solutions available in the short term; (iii) test ring, considering medium-term solutions; and (iv) explore ring, with solutions expected in the long run. This classification is done based on the technical availability of the solutions, together with the foreseen market demands. The value of this radar lies in its ability to provide a complete view of the slicing landscape with one single snapshot, by linking solutions to information that operators may use for decision making in their individual go-to-market strategies.
23
Alipour Fard, T., M. Hasanlou, and H. Arefi. "CLASSIFIER FUSION OF HIGH-RESOLUTION OPTICAL AND SYNTHETIC APERTURE RADAR (SAR) SATELLITE IMAGERY FOR CLASSIFICATION IN URBAN AREA." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-2/W3 (October 21, 2014): 25–29. http://dx.doi.org/10.5194/isprsarchives-xl-2-w3-25-2014.
Full textAbstract:
This study concerned with fusion of synthetic aperture radar and optical satellite imagery. Due to the difference in the underlying sensor technology, data from synthetic aperture radar (SAR) and optical sensors refer to different properties of the observed scene and it is believed that when they are fused together, they complement each other to improve the performance of a particular application. In this paper, two category of features are generate and six classifier fusion operators implemented and evaluated. <br><br> Implementation results show significant improvement in the classification accuracy.
24
Lindup, Paul. "How radar technology will cut the cost and duration of aerial drone surveys." Proceedings of the Institution of Civil Engineers - Civil Engineering 176, no. 1 (February 1, 2023): 12. http://dx.doi.org/10.1680/jcien.2023.176.1.12.
Full textAbstract:
Paul Lindup, chief unmanned aerial vehicle pilot at Jacobs, says civil engineers will be able to capture large linear data sets much quicker and more cheaply when the Civil Aviation Authority permits its new radar-equipped survey drones to fly beyond their operators’ line of sight.
25
Veerabathini, Surender, Sudhakara Reddy Penubolu, and Ramana Reddy Penubolu. "RCS Modeling and Validation of Full Scale Launch Vehicle for its Real Time Dynamic Trajectory." Defence Science Journal 73, no. 5 (August 31, 2023): 505–11. http://dx.doi.org/10.14429/dsj.73.18193.
Full textAbstract:
Radar Cross Section (RCS) plays a significant role in detecting and tracking the space-based objects such as launch vehicles, missiles, aircrafts etc. In space applications, Radar systems are used to track and provide real-time trajectory information of the satellite launch vehicles after the lift off from the launch pad for range safety purpose. RCS is a critical key parameter that determines tracking performance of the Radar and it is highly dependent on both Radar operating parameters and the target characteristics. For space-based applications, a good quantity of RCS is required for quick detection by the Radar for continuous tracking. In order to choose the best Radar tracking configuration for real time tracking of the launch vehicle, it is required to model and simulate the launch vehicle’s RCS fluctuations prior to launch in order to predict the real time Signal to Noise Ratio (SNR) for its complete dynamic trajectory. This modeling and simulation methodology will help to choose the optimum Radar configuration for obtaining a good quantity SNR in the real-time launch. This study also provides good guidance to Radar operators for the effective Radar operation during real time space object tracking. This paper demonstrates, the real-time RCS fluctuations of a typical ISRO launch vehicle through simulation for its dynamic trajectory using physical optics based EM software prior to launch. Furthermore, the simulation results are validated with real time monostatic Radar tracking data, which showed good agreement.
26
Junior, Milembolo Miantezila, Bin Guo, Chenjie Zhang, and Xuemei Bai. "Interference Cancellation Based Spectrum Sharing for Massive MIMO Communication Systems." Sensors 21, no. 11 (May 21, 2021): 3584. http://dx.doi.org/10.3390/s21113584.
Full textAbstract:
Cellular network operators are predicting an increase in space of more than 200 percent to carry the move and tremendous increase of total users in data traffic. The growing of investments in infrastructure such as a large number of small cells, particularly the technologies such as LTE-Advanced and 6G Technology, can assist in mitigating this challenge moderately. In this paper, we suggest a projection study in spectrum sharing of radar multi-input and multi-output, and mobile LTE multi-input multi-output communication systems near m base stations (BS). The radar multi-input multi-output and mobile LTE communication systems split different interference channels. The new approach based on radar projection signal detection has been proposed for free interference disturbance channel with radar multi-input multi-output and mobile LTE multi-input multi-output by using a new proposed interference cancellation algorithm. We chose the channel of interference with the best free channel, and the detected signal of radar was projected to null space. The goal is to remove all interferences from the radar multi-input multi-output and to cancel any disturbance sources from a chosen mobile Communication Base Station. The experimental results showed that the new approach performs very well and can optimize Spectrum Access.
27
Gonsalves, Drew B., Lawrence H. Winner, and Joseph N. Wilson. "Improvement of Handheld Radar Operators’ Hazard Detection Performance Using 3-D Visualization." IEEE Geoscience and Remote Sensing Letters 14, no. 11 (November 2017): 1888–92. http://dx.doi.org/10.1109/lgrs.2017.2704518.
Full text
28
Ambartsoumian, Gaik, Raluca Felea, Venkateswaran P. Krishnan, Clifford Nolan, and Eric Todd Quinto. "A class of singular Fourier integral operators in Synthetic Aperture Radar imaging." Journal of Functional Analysis 264, no. 1 (January 2013): 246–69. http://dx.doi.org/10.1016/j.jfa.2012.10.008.
Full text
29
Pagnini, Lorenzo, Lapo Miccinesi, Alessandra Beni, and Massimiliano Pieraccini. "Transversal Displacement Detection of an Arched Bridge with a Multimonostatic Multiple-Input Multiple-Output Radar." Sensors 24, no. 6 (March 13, 2024): 1839. http://dx.doi.org/10.3390/s24061839.
Full textAbstract:
Interferometric radars are widely used for monitoring civil structures. Bridges are critical structures that need to be constantly monitored for the safety of the users. In this work, a frequency-modulated continuous wave (FMCW) multiple-input multiple-output (MIMO) radar was used for monitoring an arched bridge in Catanzaro, Italy. Two measurements were carried out; a first standard measurement was made in a monostatic configuration, while a subsequent measurement was carried out in a multimonostatic configuration in order to retrieve the components of the deck displacement. A method that is able to predict the measurement uncertainty as a function of the multimonostatic geometry is provided, thereby aiming to facilitate the operators in the choice of the proper experimental setup. The multimonostatic measurement revealed a displacement along the horizontal direction that was four times higher than the one along the vertical direction, while the values reported in the literature correspond to a ratio of at most around 0.2. This is the first time that such a large ratio detected by radar has been reported; at any rate, it is compatible with the arched structure of this specific bridge. This case study highlights the importance of techniques that are able to retrieve at least two components of the displacement.
30
Vladimir I., Vladimir I. "Alexander A. Potapov (to 70th Anniversary oh Bird)." Radioelectronics. Nanosystems. Information Technologies. 13, no. 3 (September 30, 2021): 403–4. http://dx.doi.org/10.17725/rensit.2021.13.403.
Full textAbstract:
Is presented the information about Alexander A. Potapov - Dr Sci Phys@Math, chief researcher in Kotelnikov Institute of Radioengineering and Electronics of RAS, academician of Russian Academy of Natural Sciences, the well-known scientist in the field of radiophysics and radar, statistical radio engineering, recognition and processing of images and signals, fractal and texture analysis, fractional operators, fractal electrodynamics, fractal antennas and deterministic chaos.
31
Matsuoka, Ryo, and Shinichiro Oki. "Demonstration of Stormwater Management Technology by Short-Term Rainfall Prediction and Real-Time Runoff Analysis System Using Small X-Band Radar." Journal of Disaster Research 16, no. 3 (April 1, 2021): 403–9. http://dx.doi.org/10.20965/jdr.2021.p0403.
Full textAbstract:
We developed a system that combines urban area rainfall radar (small X-band, dual-polarization radar), short-term rainfall prediction model, and real-time runoff analysis technology, and the demonstration study was conducted on the drainage districts in Fukui City and Toyama City. We demonstrated the effectiveness of the flood damage, by providing the real-time information on rainfall prediction, water level in sewerage pipes, and inland flood prediction to the operators of drainage pump of stormwater storage pipes, and residents in flood-prone areas. During the study for about two years, it was confirmed that the accuracy of the radar rainfall observation was comparable to that of the X-band dual-polarization Doppler weather radar managed by the Ministry of Land, Infrastructure, Transport and Tourism. In the operation of the drainage pump for the Tsukimiminori Stormwater Storage Pipe in Fukui City, we were able to secure the storage capacity for the next rainfall based on the forecast information by maximizing the drainage capacity of the discharge destination. In addition, it was also confirmed that the residents themselves could secure the lead time for setting up water-stop sandbags and moving their vehicles to higher ground.
32
Twardzik, Matthias, Matteo Cecchetti, and Francesco Coppi. "An Innovative GB-INSAR System for Deformation Monitoring and Disaster Management." IOP Conference Series: Earth and Environmental Science 906, no. 1 (November 1, 2021): 012079. http://dx.doi.org/10.1088/1755-1315/906/1/012079.
Full textAbstract:
Abstract Disaster management is a critical issue, needs timely reaction to mitigate the risks and to re-establish a safety condition. For that reason, remote monitoring solution play a crucial role to measure structure healthy and slope stability keeping operators and equipment in the safe zones. A clear understanding of displacement and stability of the target is vital to define proper remediation actions, prioritizing the most critical ones. IDS GeoRadar is a provider of radar remote monitoring technology for complex structures and natural hazards, that recently developed an ArcSAR interferometric radar system for deformation monitoring and disaster management. The innovative solution has been designed to have a portable, easy-to-use solution able to monitor the structures and area after few minutes of its deployment. The radar system detects structure displacement and slope fall precursors, triggering early warning to increase safety for emergency operations and to evacuate people and machinery at risk. The new radar system provides sub-millimeter displacement accuracy at a spatial resolution of tens of centimetres, with updated displacement information every 30 seconds. In this paper, the system is described, along with emergency monitoring experiences.
33
Sitorus, Budi, and Tulus Irfan Harsono Sitorus. "PENGEMBANGAN AUTOMATIC DEPENDENT SURVEILLANCE – BROADCAST UNTUK PENINGKATAN KESELAMATAN PENERBANGAN." Jurnal Manajemen Transportasi & Logistik (JMTRANSLOG) 4, no. 3 (January 31, 2018): 303. http://dx.doi.org/10.54324/j.mtl.v4i3.69.
Full textAbstract:
The purpose of this study is to conduct a review of the existing navigation system at the airport and integrate to the flight navigation system that has been developed by the Ministry of Research and Technology to be applied to Airports in Indonesia. The research method used is qualitative research method through literature study, literature, benchmarking. Automatic Dependent Surveillance Broadcast (ADS-B) is a system designed to replace radar functions in air space management for civilian transport, can serve as a substitute or for traditional radar-based aircraft surveillance supplements. The use of ADS-B was recommended by the International Civil Aviation Organization (ICAO) in May 2006. Using ADS-B, detection would be better and more accurate than when using a radar system where existing radar systems can not detect unobstructed aircraft . The use of the ADS-B system in Indonesia began in 2006, in partnership with SITA and Thales. In this regard, Indonesia has 30 (thirty) earth stations ready for operation. In general, both flight monitoring systems are very helpful for APP operators (Approach and departure control) in terms of providing a picture of flight traffic conditions around the airport.
34
Shrestha, Prabhakar, Jana Mendrok, Velibor Pejcic, Silke Trömel, Ulrich Blahak, and Jacob T. Carlin. "Evaluation of the COSMO model (v5.1) in polarimetric radar space – impact of uncertainties in model microphysics, retrievals and forward operators." Geoscientific Model Development 15, no. 1 (January 17, 2022): 291–313. http://dx.doi.org/10.5194/gmd-15-291-2022.
Full textAbstract:
Abstract. Sensitivity experiments with a numerical weather prediction (NWP) model and polarimetric radar forward operator (FO) are conducted for a long-duration stratiform event over northwestern Germany to evaluate uncertainties in the partitioning of the ice water content and assumptions of hydrometeor scattering properties in the NWP model and FO, respectively. Polarimetric observations from X-band radar and retrievals of hydrometeor classifications are used for comparison with the multiple experiments in radar and model space. Modifying the critical diameter of particles for ice-to-snow conversion by aggregation (Dice) and the threshold temperature responsible for graupel production by riming (Tgr), was found to improve the synthetic polarimetric moments and simulated hydrometeor population, while keeping the difference in surface precipitation statistically insignificant at model resolvable grid scales. However, the model still exhibited a low bias (lower magnitude than observation) in simulated polarimetric moments at lower levels above the melting layer (−3 to −13 ∘C) where snow was found to dominate. This necessitates further research into the missing microphysical processes in these lower levels (e.g. fragmentation due to ice–ice collisions) and use of more reliable snow-scattering models to draw valid conclusions.
35
Podkovka, O. I., M. Y. Makarchuk, N. B. Filimonova, I. V. Pampuha, and Ye V. Varzhanska. "NEUROBIOLOGICAL AND PSYCHOPHYSIOLOGICAL DIFFERENCES OF VISUAL WORKING MEMORY FUNCTIONING IN RADAR STATION OPERATORS." Fiziolohichnyĭ zhurnal 69, no. 6 (November 10, 2023): 22–32. http://dx.doi.org/10.15407/fz69.06.022.
Full textAbstract:
Operators are often subjected to a high working memory load as far as any possibly useful information must always be available and presented to the operator. Thus, we assumed that they may have developed adaptations in mechanisms of working memory realization that help them to be more efficient in information overload conditions. Our aim was to define differences in visual working memory functioning in radar station operators (RSO) and other military profession representatives. For this purpose, in parallel with the performance of original computer tests for the visual working memory identification, which had two levels of complexity, we recorded an electroencephalogram with subsequent coherent and LORETA analysis and electrocardiogram with subsequent determining of stress index of the regulatory systems. It was found that reaction time, as well as the number of errors in both tests, didn`t differ significantly for the two groups. At the same time, the control group had a significantly higher number of θ-band coherent connections in the frontal lobe in both tests, which could indicate a higher level of mental stress and emotional involvement. This assumption was confirmed by the stress index dynamic in the control group. LORETA analysis showed that in the RSO group, the degree of fronto-parietal, cingulo-opercular networks, cuneus and precuneus involvement was at a high level from the very first tasks, while in the control group, it increased with task complexity, that is the evidence of adaptive changes in the working memory of RSO, due to which they successfully cope with information overload.
36
Тимошенко, А. В., А. В. Осипов, and Д. А. Харебин. "Proactive management of the functional characteristics of the radar complex according to the data of automated educational and training tools." МОДЕЛИРОВАНИЕ, ОПТИМИЗАЦИЯ И ИНФОРМАЦИОННЫЕ ТЕХНОЛОГИИ 9, no. 4(35) (October 20, 2021): 4–5. http://dx.doi.org/10.26102/2310-6018/2021.35.4.004.
Full textAbstract:
В статье рассмотрен вопрос обеспечения эффективности применения проактивного управления функциональными характеристиками радиолокационного комплекса с учетом технической готовности аппаратно-программных средств и уровня подготовки операторов и обслуживающего персонала. Подчеркивается важность вклада человеческого фактора в обеспечение боеготовности и эффективности применения радиолокационного комплекса по назначению. В результате проведенного анализа существующего методического аппарата оценки уровня подготовки операторов и обслуживающего персонала для реализации современных методов проактивного управления, определена необходимость и пути его совершенствования на базе принятого априори в Российской Федерации компетентностного подхода. Введены понятия профессионального компетентностного портрета оператора и эталонного профессионального компетентностного портрета, описывающего необходимый и достаточный набор компетенций, требуемый оператору для своевременного и эффективного управления и применения радиолокационного комплекса. Описана информационная модель профессионального компетентностного портрета, предложена метрика расчета количественной интегральной оценки уровня его сформированности, применимая для программной реализации в составе автоматизированных учебно-тренировочных средств. Приведена схема применения автоматизированных учебно-тренировочных средств при решении оперативных задач проактивного управления радиолокационным комплексом. Отмечена необходимость использования Big Data оперативных данных ремонтно-диагностического комплекса по обнаружению признаков, определению причин и устранению / предотвращению отказов, а также архивных и актуальных данных от автоматизированных учебно-тренировочных средств о состоянии подготовки операторов и обслуживающего персонала в процессе проактивного управления радиолокационным комплексом. На основании полученных результатов можно сделать вывод о целесообразности комплексирования учебно-тренировочных средств и систем технического и функционального контроля радиолокационного комплекса в целях достижения заданного уровня вероятности выполнения задач радиолокационного комплекса по назначению. This article considers the issue of ensuring the effective use of proactive control of the functional characteristics of the radar complex, taking into account the technical readiness of hardware and software and the level of training of operators and maintenance personnel. The importance of the human factor contribution in ensuring the combat readiness and effectiveness of the use of the radar complex for its intended purpose is emphasized. As a result of the analysis of the existing methodological apparatus for assessing the level of training of operators and service personnel for the modern proactive management methods implementation, the necessity and ways of improving it are determined based on the competence approach adopted a priori in the Russian Federation. The concepts of the professional competence portrait of the operator and the reference professional competence portrait describing the necessary and sufficient set of competencies required by the operator for timely and effective management and application of the radar complex are introduced. An information model of a professional competence portrait is described, a metric for calculating a quantitative integral assessment of the level of its formation is proposed, which is applicable for software implementation as part of automated training tools. The scheme of application of automated training tools for solving operational tasks of proactive control of the radar complex is presented. The necessity of using Big Data of operational data of the repair and diagnostic complex for detecting signs, determining the causes and eliminating/preventing failures, as well as archival and up-to-date data from automated training facilities on the state of training of operators and maintenance personnel in the process of proactive control of the radar complex is noted. Based on the results obtained, it can be concluded that it is advisable to integrate training facilities and systems of technical and functional control of the radar complex to achieve a given level of probability of performing the tasks of the radar complex according to its intended purpose.
37
Putnam, Bryan, Ming Xue, Youngsun Jung, Nathan Snook, and Guifu Zhang. "Ensemble Kalman Filter Assimilation of Polarimetric Radar Observations for the 20 May 2013 Oklahoma Tornadic Supercell Case." Monthly Weather Review 147, no. 7 (June 28, 2019): 2511–33. http://dx.doi.org/10.1175/mwr-d-18-0251.1.
Full textAbstract:
Abstract Real polarimetric radar observations are directly assimilated for the first time using the ensemble Kalman filter (EnKF) for a supercell case from 20 May 2013 in Oklahoma. A double-moment microphysics scheme and advanced polarimetric radar observation operators are used together to estimate the model states. Lookup tables for the observation operators are developed based on T-matrix scattering amplitudes for all hydrometeor categories, which improve upon previous curved-fitted approximations of T-matrix scattering amplitudes or the Rayleigh approximation. Two experiments are conducted: one assimilates reflectivity (Z) and radial velocity (Vr) (EXPZ), and one assimilates in addition differential reflectivity (ZDR) below the observed melting level at ~2-km height (EXPZZDR). In the EnKF analyses, EXPZZDR exhibits a ZDR arc that better matches observations than EXPZ. EXPZZDR also has higher ZDR above 2 km, consistent with the observed ZDR column. Additionally, EXPZZDR has an improved estimate of the model microphysical states. Specifically, the rain mean mass diameter (Dnr) in EXPZZDR is higher in the ZDR arc region and the total rain number concentration (Ntr) is lower downshear in the forward flank than EXPZ when compared to values retrieved from the polarimetric observations. Finally, a negative gradient of hail mean mass diameter (Dnh) is found in the right-forward flank of the EXPZZDR analysis, which supports previous findings indicating that size sorting of hail, as opposed to rain, has a more significant impact on low-level polarimetric signatures. This paper represents a proof-of-concept study demonstrating the value of assimilating polarimetric radar data in improving the analysis of features and states related to microphysics in supercell storms.
38
Mohr, Veronika, and Martin Gade. "Marine Oil Pollution in an Area of High Economic Use: Statistical Analyses of SAR Data from the Western Java Sea." Remote Sensing 14, no. 4 (February 12, 2022): 880. http://dx.doi.org/10.3390/rs14040880.
Full textAbstract:
In this paper, we analyze more than 2000 Synthetic Aperture Radar (SAR) images of the Western Java Sea acquired by Sentinel-1 SAR-C and ENVISAT ASAR, with the aim to generate oil pollution statistics for a sea region of high economic use. The spatial distributions show that most oil pollution occurs along the major shipping routes and at oil production sites in that area. The majority of the spills have sizes of less than 1 km2 and an axial ratio smaller than 10. For two sets of SAR images, we compared the results obtained by different operators, who analyzed the same images. While more than 50% of the spills were not found by both operators, the overall spatial patterns derived from their results are the same. Our results indicate that the observed differences are mainly due to lookalikes, which can easily be confused with oil spills, but also due to small oil spills that were overseen by one of the operators. These assumptions are supported by the fact that the percentage of spills jointly found by both operators increased when only oil spills were considered that were found on SAR images acquired at higher mean wind speeds.
39
Ma, Wenping, Xiaoting Li, Yue Wu, Licheng Jiao, and Dan Xing. "Data Fusion and Fuzzy Clustering on Ratio Images for Change Detection in Synthetic Aperture Radar Images." Mathematical Problems in Engineering 2014 (2014): 1–14. http://dx.doi.org/10.1155/2014/403095.
Full textAbstract:
The unsupervised approach to change detection via synthetic aperture radar (SAR) images becomes more and more popular. The three-step procedure is the most widely used procedure, but it does not work well with the Yellow River Estuary dataset obtained by two synthetic aperture radars. The difference of the two radars in imaging techniques causes severe noise, which seriously affects the difference images generated by a single change detector in step two, producing the difference image. To deal with problem, we propose a change detector to fuse the log-ratio (LR) and the mean-ratio (MR) images by a context independent variable behavior (CIVB) operator and can utilize the complement information in two ratio images. In order to validate the effectiveness of the proposed change detector, the change detector will be compared with three other change detectors, namely, the log-ratio (LR), mean-ratio (MR), and the wavelet-fusion (WR) operator, to deal with three datasets with different characteristics. The four operators are applied not only in a widely used three-step procedure but also in a new approach. The experiments show that the false alarms and overall errors of change detection are greatly reduced, and the kappa and KCC are improved a lot. And its superiority can also be observed visually.
40
Wang, Shizhang, and Zhiquan Liu. "A radar reflectivity operator with ice-phase hydrometeors for variational data assimilation (version 1.0) and its evaluation with real radar data." Geoscientific Model Development 12, no. 9 (September 13, 2019): 4031–51. http://dx.doi.org/10.5194/gmd-12-4031-2019.
Full textAbstract:
Abstract. A reflectivity forward operator and its associated tangent linear and adjoint operators (together named RadarVar) were developed for variational data assimilation (DA). RadarVar can analyze both rainwater and ice-phase species (snow and graupel) by directly assimilating radar reflectivity observations. The results of three-dimensional variational (3D-Var) DA experiments with a 3 km grid mesh setting of the Weather Research and Forecasting (WRF) model showed that RadarVar was effective at producing an analysis of reflectivity pattern and intensity similar to the observed data. Two to three outer loops with 50–100 iterations in each loop were needed to obtain a converged 3-D analysis of reflectivity, rainwater, snow, and graupel, including the melting layers with mixed-phase hydrometeors. It is shown that the deficiencies in the analysis using this operator, caused by the poor quality of the background fields and the use of the static background error covariance, can be partially resolved by using radar-retrieved hydrometeors in a preprocessing step and tuning the spatial correlation length scales of the background errors. The direct radar reflectivity assimilation using RadarVar also improved the short-term (2–5 h) precipitation forecasts compared to those of the experiment without DA.
41
Li, Xuanli, John R. Mecikalski, and Derek Posselt. "An Ice-Phase Microphysics Forward Model and Preliminary Results of Polarimetric Radar Data Assimilation." Monthly Weather Review 145, no. 2 (February 2017): 683–708. http://dx.doi.org/10.1175/mwr-d-16-0035.1.
Full textAbstract:
In this study, an ice-phase microphysics forward model has been developed for the Weather Research and Forecasting (WRF) Model three-dimensional variational data assimilation (WRF 3D-Var) system. Radar forward operators for reflectivity and the polarimetric variable, specific differential phase ( KDP), have been built into the ice-phase WRF 3D-Var package to allow modifications in liquid (cloud water and rain) and solid water (cloud ice and snow) fields through data assimilation. Experiments have been conducted to assimilate reflectivity and radial velocity observations collected by the Weather Surveillance Radar-1988 Doppler (WSR-88D) in Hytop, Alabama, for a mesoscale convective system (MCS) on 15 March 2008. Numerical results have been examined to assess the impact of the WSR-88D data using the ice-phase WRF 3D-Var radar data assimilation package. The main goals are to first demonstrate radar data assimilation with an ice-phase microphysics forward model and second to improve understanding on how to enhance the utilization of radar data in numerical weather prediction. Results showed that the assimilation of reflectivity and radial velocity data using the ice-phase system provided significant improvement especially in the mid- to upper troposphere. The improved initial conditions led to apparent improvement in the short-term precipitation forecast of the MCS. An additional experiment has been conducted to explore the assimilation of KDP data collected by the Advanced Radar for Meteorological and Operational Research (ARMOR). Results showed that KDP data have been successfully assimilated using the ice-phase 3D-Var package. A positive impact of the KDP data has been found on rainwater in the lower troposphere and snow in the mid- to upper troposphere.
42
Li, Meng, Han Wei, Yao Ge, Guocai Xiao, and Yaowei Yu. "A Mathematical Model Combined with Radar Data for Bell-Less Charging of a Blast Furnace." Processes 8, no. 2 (February 20, 2020): 239. http://dx.doi.org/10.3390/pr8020239.
Full textAbstract:
Charging directly affects the burden distribution of a blast furnace, which determines the gas distribution in the shaft of the furnace. Adjusting the charging can improve the distribution of the gas flow, increase the gas utilization efficiency of the furnace, reduce energy consumption, and prolong the life of the blast furnace. In this paper, a mathematical model of blast furnace charging was developed and applied on a steel plant in China, which includes the display of the burden profile, burden layers, descent speed of the layers, and ore/coke ratio. Furthermore, the mathematical model is developed to combine the radar data of the burden profile. The above model is currently used in Nanjing Steel as a reference for operators to adjust the charging. The model is being tested with a radar system on the blast furnace.
43
Chepurnov, Ilya, and Vladimir Prokhorenko. "Simulation Modelling of a Radar Semi-Active Homing System for a Guided Missile at an Air Target." Ergodesign 2024, no. 2 (May 31, 2024): 173–79. http://dx.doi.org/10.30987/2658-4026-2024-2-173-179.
Full textAbstract:
The problem of improving mathematical models of computer simulators for anti-aircraft missile systems has been updated. The paper considers private simulation models of the homing process of a guided missile at an air target and the coverage area of a sector multifunctional radar station developed at the Department of Anti-Aircraft Missile Forces of the Military Training Centre of Bauman Moscow State Technical University. The paper describes a software application for simulating a radar semi-active homing system for a guided missile at an air target, developed by the authors using the MATLAB package. The presented simulation models and software application can be used both in developing and improving computer training models, and as part of individual automated instruction systems for training operators of anti-aircraft missile systems at military universities and in military training centers.
44
Jordi, C., J. Doetsch, T. Günther, C. Schmelzbach, H. Maurer, and J. O. A. Robertsson. "Structural joint inversion on irregular meshes." Geophysical Journal International 220, no. 3 (December 5, 2019): 1995–2008. http://dx.doi.org/10.1093/gji/ggz550.
Full textAbstract:
SUMMARY Structural joint inversion of several data sets on an irregular mesh requires appropriate coupling operators. To date, joint inversion algorithms are primarily designed for the use on regular rectilinear grids and impose structural similarity in the direct neighbourhood of a cell only. We introduce a novel scheme for calculating cross-gradient operators based on a correlation model that allows to define the operator size by imposing physical length scales. We demonstrate that the proposed cross-gradient operators are largely decoupled from the discretization of the modelling domain, which is particularly important for irregular meshes where cell sizes vary. Our structural joint inversion algorithm is applied to a synthetic electrical resistivity tomography and ground penetrating radar 3-D cross-well experiment aiming at imaging two anomalous bodies and extracting the parameter distribution of the geostatistical background models. For both tasks, joint inversion produced superior results compared with individual inversions of the two data sets. Finally, we applied structural joint inversion to two field data sets recorded over a karstified limestone area. By including geological a priori information via the correlation-based operators into the joint inversion, we find P-wave velocity and electrical resistivity tomograms that are in accordance with the expected subsurface geology.
45
Jung, Youngsun, Guifu Zhang, and Ming Xue. "Assimilation of Simulated Polarimetric Radar Data for a Convective Storm Using the Ensemble Kalman Filter. Part I: Observation Operators for Reflectivity and Polarimetric Variables." Monthly Weather Review 136, no. 6 (June 1, 2008): 2228–45. http://dx.doi.org/10.1175/2007mwr2083.1.
Full textAbstract:
Abstract A radar simulator for polarimetric radar variables, including reflectivities at horizontal and vertical polarizations, the differential reflectivity, and the specific differential phase, has been developed. This simulator serves as a test bed for developing and testing forward observation operators of polarimetric radar variables that are needed when directly assimilating these variables into storm-scale numerical weather prediction (NWP) models, using either variational or ensemble-based assimilation methods. The simulator takes as input the results of high-resolution NWP model simulations with ice microphysics and produces simulated polarimetric radar data that may also contain simulated errors. It is developed based on calculations of electromagnetic wave propagation and scattering at the S band of wavelength 10.7 cm in a hydrometeor-containing atmosphere. The T-matrix method is used for the scattering calculation of raindrops and the Rayleigh scattering approximation is applied to snow and hail particles. The polarimetric variables are expressed as functions of the hydrometeor mixing ratios as well as their corresponding drop size distribution parameters and densities. The presence of wet snow and wet hail in the melting layer is accounted for by using a new, relatively simple melting model that defines the water fraction in the melting snow or hail. The effect of varying density due to the melting snow or hail is also included. Vertical cross sections and profiles of the polarimetric variables for a simulated mature multicellular squall-line system and a supercell storm show that polarimetric signatures of the bright band in the stratiform region and those associated with deep convection are well captured by the simulator.
46
Dehghan, Naser, and Shahram Taeb. "Adverse health effects of occupational exposure to radiofrequency radiation in airport surveillance radar operators." Indian Journal of Occupational and Environmental Medicine 17, no. 1 (2013): 7. http://dx.doi.org/10.4103/0019-5278.116365.
Full text
47
Degrave, Etienne, Philippe Autier, André-Robert Grivegnée, and Martin Zizi. "All-Cause Mortality Among Belgian Military Radar Operators: A 40-Year Controlled Longitudinal Study." European Journal of Epidemiology 20, no. 8 (August 2005): 677–81. http://dx.doi.org/10.1007/s10654-005-7922-z.
Full text
48
LI, Xuanli, and John R. MECIKALSKI. "Evaluation of The Sensitivity of The Dual-Polarization Doppler Warm-Rain Radar Data Assimilation to Radar Forward Operators for a Convective Storm." Journal of the Meteorological Society of Japan. Ser. II 91, no. 3 (2013): 287–304. http://dx.doi.org/10.2151/jmsj.2013-304.
Full text
49
Heo, Jinmoo, Yongchul Jung, Seongjoo Lee, and Yunho Jung. "FPGA Implementation of an Efficient FFT Processor for FMCW Radar Signal Processing." Sensors 21, no. 19 (September 27, 2021): 6443. http://dx.doi.org/10.3390/s21196443.
Full textAbstract:
This paper presents the design and implementation results of an efficient fast Fourier transform (FFT) processor for frequency-modulated continuous wave (FMCW) radar signal processing. The proposed FFT processor is designed with a memory-based FFT architecture and supports variable lengths from 64 to 4096. Moreover, it is designed with a floating-point operator to prevent the performance degradation of fixed-point operators. FMCW radar signal processing requires windowing operations to increase the target detection rate by reducing clutter side lobes, magnitude calculation operations based on the FFT results to detect the target, and accumulation operations to improve the detection performance of the target. In addition, in some applications such as the measurement of vital signs, the phase of the FFT result has to be calculated. In general, only the FFT is implemented in the hardware, and the other FMCW radar signal processing is performed in the software. The proposed FFT processor implements not only the FFT, but also windowing, accumulation, and magnitude/phase calculations in the hardware. Therefore, compared with a processor implementing only the FFT, the proposed FFT processor uses 1.69 times the hardware resources but achieves an execution time 7.32 times shorter.
50
Jo, M. J., B. Osmanoglu, B. Zhang, and S. Wdowinski. "FLOOD EXTENT MAPPING USING DUAL-POLARIMETRIC SENTINEL-1 SYNTHETIC APERTURE RADAR IMAGERY." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-3 (April 30, 2018): 711–13. http://dx.doi.org/10.5194/isprs-archives-xlii-3-711-2018.
Full textAbstract:
Rapid generation of synthetic aperture radar (SAR) based flood extent maps provide valuable data in disaster response efforts thanks to the cloud penetrating ability of microwaves. We present a method using dual-polarimetric SAR imagery acquired on Sentinel-1a/b satellites. A false-colour map is generated using pre- and post- disaster imagery, allowing operators to distinguish between existing standing water pre-flooding, and recently flooded areas. The method works best in areas of standing water and provides mixed results in urban areas. A flood depth map is also estimated by using an external DEM. We will present the methodology, it’s estimated accuracy as well as investigations into improving the response in urban areas.