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Nowadays, automatic car is a very popular topic. The successive and safe steering of automatic car required high abilities in sensor system in order to detect emergencies immediately. However, it's impossible for one kind of radar filling up all the needs in different working environments. As a result, most of the automatic car companies decide to apply several types of radar sensor which can fit in all situations that contains strong light, noise, sudden movement and so on. The whole radar system mainly consists of laser radar, camera, ultrasonic radar and so on. This discussion will cover the laser radar, one of the most essential components in an autonomous vehicle. The paper will specifically focus on two primary principles used in laser radar for distance measurement: FMCW technology and TOF technology. And the advantages and disadvantages will be explained in more readable ways. Besides, an experiment of a well-designed TOF system will be introduced. [ABSTRACT FROM AUTHOR]

Synthetic aperture radar (SAR) is a powerful tool for remote sensing of the Earth's surface. The variety of practically important characteristics of a radar image quality and the radio observation conditions that determine them make it reasonable to introduce an unified indicator allowing at least a qualitative estimation of the influence of various factors on the potential radar observation efficiency, regardless of the signal processing method. As such an indicator, the amount of information contained in the reflected signal regarding the state of the observed object can be taken. Ratios are provided for decision-making on the efficiency of various approaches to the radio observation based on information-theoretic methods in terms of the indicators characterizing the amount of information received about the state of the observed object. The qualitative consideration carried out in this study ensures specifying the amount of information as a measure of the efficiency of radio observation during an aperture synthesis. [ABSTRACT FROM AUTHOR]

This paper proposes and implements a real-time word-level Arabic Sign Language (ARSL) recognition system. The work aims to facilitate the interaction between people with hearing loss and the general public. The system uses a frequency-modulated continuous wave (FM-CW) radar operating at 77 GHz millimeter frequency to transmit and capture signals from a person performing hand gestures in front of the radar. The signals are then used to train a convolutional neural network (CNN) to translate the gestures into words. The CNN is built using the Keras platform on Python and has ten layers, including two 2D convolutional layers. In the preliminary work, the system is designed to identify ten important common words. Preliminary results show that the system can classify gestures correctly in real time with 81% accuracy. [ABSTRACT FROM AUTHOR]

The best tool for acquiring information is research, this is one of the reasons why man is distinguished from other species on planet Earth. In man's desire to understand the nature that surrounds him, various obstacles appeared, one of which is being able to enter places that are difficult to physically access such as canyons or sea caves. It is for this reason that a means is developed by which three-dimensional modeling of the aquatic surface will be carried out based on the detection of obstacles and measurement of distance using ultrasound. This project presents the response to this problem through the use of ultrasound, which is responsible for sending and receiving sound waves for measuring distance on aquatic surfaces and the use of a radar that sends and receives electromagnetic waves with the objective to detect obstacles in the research route. The results of the development of this project are greater access to natural or superficial places with complicated characteristics for human entry, allowing the recognition of the interior of these ecosystems through modeling of the environment in which the environment is located. In short, the progress of this project will be of great contribution to different sectors such as research, construction, social, among others, whose procedure is the prior study of the environment for the development of the work. [ABSTRACT FROM AUTHOR]

Radio Detection and Ranging System (RADAR) is an acronym for Radio Detection and Ranging System. It's essentially an electromagnetic method for detecting the position and object distance from the RADAR's location. It operates by emitting energy into space and measuring the objects' echo or reflected signal. It works in the UHF and microwave frequencies. Radar works by sending electromagnetic radiation in the direction of objects and then observing the echoes and returns. Queuing theory is used to understand how radar works. This method depicts the radar transmission process in terms of Queuing parameters. This study uses the queuing idea to approach the aforementioned radar data communication process. The queuing mindset identifies communication flaws and allows the critical mind to be dispatched in order to reduce connection disruptions. Furthermore, this research employs the queuing idea to deal with delays and other issues that may arise during the process. Queues can aid in the discovery of inefficiencies in the system and the generation of solutions for reducing aid waste. For the chosen queue studies, all distinct overall performance metrics, as well as the queue length possibility producing function, are determined. A numerical and specified visual analysis depicts the theoretical examination of the queuing idea in Radar data communication. [ABSTRACT FROM AUTHOR]

A Novel indented 4-component MIMO (Multi-input-Multi Output)antenna with hole sleeves and H-opening is proposed and created for UWB(Ultra-Wide Band) applications. The proposed is Co-Planar waveguide receiving wire took care of and comprises of four symmetrical components with great disconnection. The dimensions of the proposed has low profileof 80×80×1.6mm3. The proposed MIMO receiving wire accomplished an impedance data transmission (S11<10dB) from 2.1GHz-20GHz with scores from 3.3GHz-4.1GHz and 8.2GHz-8.6GHzfrequencybands. These accomplished indents can channel the obstruction of Wi MAX(3.3GHz-3.7GHz), and military/radar applications band(8.2GHz-8.6GHz). Mutual coupling among the components is likewise underneath 25dB. The presentation boundary of proposed MIMO reception apparatus is moderately acceptable with extremely low ECC(Envelop Correlation Coefficient) which is under 0.02 excepted indents and DG (Diversity Gain) almost 10. Pinnacle addition of 5.8 dB is accomplished by the suggested receiving wire the radiation productivity is additionally above 80% aside from at scores. The PC produced and test results are in accord. So, the proposed four component MIMO receiving wire can be endorsed as an appropriate hopeful for UWB applications with stop groups for Wi-MAX and military/radar applications. [ABSTRACT FROM AUTHOR]

The Bureau currently generates various rainfall products, reporting observed precipitation data at diverse spatial scales, accumulated over different time frames, and provided in several formats. These products are derived from various instruments, including rain gauges, radars, and satellites. Each instrument offers unique benefits and has specific limitations. Recognising this, there is a need to blend these data into a single product that caters to an array of hydrological applications. This presentation will focus on our innovative methodology for blending rainfall data. This approach amalgamates Rainfields data, which is a quality-controlled radar product collated from weather radar across Australia, with Himawari satellite data and observations from rain gauges. Our analysis draws upon components of the Short-Term Ensemble Prediction System (STEPS). This system employs a multiplicative cascade model of rainfall and merges multiple data sources at various cascade levels. The weights assigned in this blending process are determined based on the mutual correlation of the data at each cascade level. To address the inherent uncertainties of each data source, we have incorporated spatial error properties into our methodology. For the rain gauge data, we use Kriging covariance. In the case of radar data, we factor in an error field that takes into account both topography and distance from the radar location. For satellite data, we utilise the residual error from the bias-corrected satellite data to detect and accommodate error properties. At present, our blending methodology has been applied and tested in regions of 1024x1024 km around Brisbane, Sydney, and Melbourne. Looking forward, we plan to extend this methodology to a continental scale, enabling us to provide data updates at hourly intervals. This comprehensive and timely data will prove invaluable for a wide range of hydrological applications. [ABSTRACT FROM AUTHOR]

In the current world, ultrasonic innovation is perhaps the most utilized ones on the lookout for quite a long time is as yet thought to be a confided in innovation in modern applications. The plan in regards to the ultrasonic radar is exceptionally valuable for numerous applications like in the homes, military, remembering a crucial job for the aviation and Flying Corps needs. They assume a significant part in object discovery. Also, this work attempts to assemble an ultrasonic handset which is the assortment of radar frameworks to get precise outcomes as far as distance and length in the recognitions and this plotted for the fixed items set all through the speed of the ultrasonic waves in the free air. These were things get some medium like a microcontroller to get and send the ultrasonic waves through 40kHz to give the flexibleness of client prerequisites. A suspension happened between the transmitted and the received waves that oversee the impression of sound. A few tests were finished by the setting of two alerts: the visual caution is finished by a PC screen planned by radar screen. Also, the discernible signal sound alert which is performed by a LCD computerized screen. [ABSTRACT FROM AUTHOR]

The municipality of Fusagasugá is located 50 kilometers from the city of Bogotá, Colombia, in the eastern cordillera of the Andes in South America. Due to its geographical location, a mountainous area with heights between 1000 and 2000 meters above sea level and two rainy seasons a year, it is affected by processes of instability and surface deformations. The objective of the present investigation was to identify and quantify the displacement speeds of the zones affected by processes of instability and superficial deformation. In this study, 20 radar satellite images from the Sentinel-1 program were used in the SLC format between 30 January 2020 and 19 April 2022 in descending orbit, applying the Small Base Line (SBAS) technique. On the other hand, 21 SAR images were also used in descending orbit between 6 January 2020 and 14 December 2021, applying the persistent scatterers (PS) technique. With the above information, it was possible to map and update the data of the municipality of Fusagasugá in order to include them in the monitoring processes at the regional level. [ABSTRACT FROM AUTHOR]

Flash floods is a big flood that comes suddenly by overflowing, inundating and flowing fast so that it can wash away objects around it. Cold lava flash floods are very dangerous, especially in the southwest area of Merapi Mountain which is often caused by heavy rainfall. This study aims to calculate the lag time of rain before arriving at the surface using X-Band radar data and ARR (Automatic Rainfall Recorder) data, it because of the raindrop movement from space into the ground contains a delay time which can be use to develop the system of early warning for flash floods. In this research, the rain gauge data was collected from Hydraulics Laboratory of Gadjah Mada University website from two rain gauge stations namely BE-D4 located in Krasak River area and BO (Donoharjo) located in Boyong River Area. Meanwhile, the Radar data was collected from the CEED Hydraulic Lab SATREPS project data base in binary form (.scn) which needed to be processed using the program code in Python application assisted by the Visual Studio Code application as an IDE (Integrated Development Environment). From this processing, the program can be read binary data and help us to calculate the interpolation and visualization of CAPPI (Constant Altitude Plan Position Indicator) and VCUT (Vertical Cut). The result will be used to find out the value of cross-correlation and the lag time using the equation by Paul Bourke. From the analyze, the result showed that the maximum correlation in BE-D4 station is 0.89 with the best lag time 35 minutes from elevation 3000 meters and in BO (Donoharjo) the maximum correlation is 0.91 with the best lag time 5 minutes from elevation 1500 meters. Moreover, from Cappi movement visualization it can be seen that the tendency of the rain movement at 12.00-12.24 is to the west. In conclusion, from that analysis, it is found the best time lag for early warning system of flash floods in the Krasak River and Boyong River areas to be a reference of flash floods mitigation which caused by high intensity rainfall. [ABSTRACT FROM AUTHOR]

The recent advent of cost-effective high accuracy radar sensors has seen the replacement of float and encoder type mechanical tide gauges that were in use for more than 150 years. Technological change is coming faster than it takes to systematically compare and analyse the new technology to the old. The Van de Casteele diagram has been tested to ascertain its usefulness against the new technologies. Using dual sensor equipped tide gauge stations around the coast of Queensland, we compared the sensor readings to assess and identify any installation or sensor setup problems. The Van de Casteele method of comparing readings of different sensors could be further used to assess potential problems to radar sensor readings by temperature change or the introduction of electromagnetic interference. [ABSTRACT FROM AUTHOR]

In this paper problem mathematic modeling of radar system to measure inter-satellite parameters spaceship to space station is discussed. Modern space stations like International Space Station have big area of outer surface and then electromagnetic waves emitted by antenna are reflected from this surface and make interference with direct waves. This leads to errors in parameter measurement and fault of system of automatic rendezvous and docking. Author presents new algorithm to find reflected electromagnetic wave using physical optics approximation and ray tracing approach. Presented mathematic modeling algorithm is used in new approach to analyze trajectory of rendezvous spaceship to space station to find segments where radar system can work in wrong way. Described algorithms are implemented in modeling software, which was used for analysis of approaching and docking trajectories cargo and transport spaceships to International Space Station. The results of modeling are compared with telemetric information received from spaceships and International Space Station. [ABSTRACT FROM AUTHOR]

In this paper Quasi-TEM based Microstrip inter digital Ultra-wideband (UWB) BPF for radar Band X, Ku band were planned with quarter wave inverter and band coupled lines. The filter was intended to accomplish the Fractional Bandwidth (FBW) of 0.33, insertion loss(S12) of less than 0.5 dB in the passband, are turn loss(S11) of -20 dB and 20dB on one or the other side at 4.0 GHz from center frequency. The proposed filter was acknowledged and simulated effectively on a 20 mil thickness Rogers' RT Duroid 6035 substrate having a dielectric constant (εr) of 3.55. The design has demonstrated in a compact size filter of 9.02 × 10 × 0.508mm3. This Ultra-wideband (UWB) band pass Filter demonstrated and simulated utilizing HFSS (High Frequency Structure Simulator). [ABSTRACT FROM AUTHOR]

This paper is collaboration between BMKG and the University of Mataram to mitigate landslides by utilizing C-band radar data and rain gauges in measuring rainfall as the main factor triggering disasters. In heavy and prolonged rains, there is a chance for disasters to occur. Based on the observations of the Lombok International Airport Meteorological Station (-8°76'59"LS and 116°27''91"E), the 24-hour cumulative rain on January 30, 2021, the analysis results of 64 mm/h can be included in the category of extrime rainfall. [ABSTRACT FROM AUTHOR]

Railway crossing has always been a source of increased danger for vehicles and pedestrians crossing it. Every year in Russia, several hundred-road accidents occur at railway crossings, dozens of people die. To increase the safety of traffic at railway crossings, automatic systems for detection of objects in the immediate danger zone can be used. These are sensors of optical (cameras, lidars) and radio ranges. The main disadvantage of optical devices is their limited functionality in insufficient visibility conditions: snowfall, rain, fog. Note that the radar is devoid of this disadvantage and retains its specified detection characteristics under any weather conditions. The paper deals with the analysis of the approach to form the directivity characteristics of the phased antenna array for 24 GHz FMCW radar used in the system of automatic control at the railway crossings. The feature of the proposed technique is applying of two widely spaced incoherent omnidirectional in azimuthal plane transmitters that provide the interferometric structure of transmit pattern. The important requirement for radar systems of detecting objects at a railway crossing are a wide field of view (up to 90 degrees) and, at the same time, high accuracy in determining coordinates. The last requirement assumes a relatively high resolution in angular coordinates (several degrees). The proposed structure of the transmitting antenna array allows the improvement of the angular resolution in comparison with the conventional array with the same aperture. The receiving antenna array should provide a low level of the sidelobes and a given beamwidth of the radar directivity pattern. The rotation of the beam of the receiving phased antenna array is carried out in the digital signal processing (DSP) system, since separated phase shifters are also not used in receivers. Optimization was carried out on the level of the side lobes and the resulting width of the radar beam. To reduce the side lobe level, a sidelobe compensation method is used. It is known, zero is formed in DP of the compensation channel in the direction of the maximum of DP of the main channel. In the presented work, the central six channels of the receiver are used to form the main beam. In the case of a compensation beam, the first six channels have the opposite phase to the rest to form a zero of DP. Theoretical justification is presented. The results of mathematical modeling are shown. To study the features of work in a real railway crossing, a prototype of 24 GHz radar was designed. Also, transmit and receive positions of FSR were used. The work of the prototype was studied in the conditions when objects of interest, including cars and pedestrians, were moving through the crossing. The results of the prototype testing are also presented. [ABSTRACT FROM AUTHOR]

In the framework of the ESA-NASA Joint Aeolus Tropical Atlantic Campaign (JATAC), the ASKOS experiment was implemented during the summer and autumn of 2021 and 2022. ASKOS comprised roughly 9 weeks of measurements in the Saharan dust outflow towards the North Atlantic, with operations conducted from the Cabo Verde Islands. Through its unprecedented dataset of synergistic measurements in the region, ASKOS will allow for the calibration and validation of the aerosol/cloud product from Aeolus and the preparation of the terrain for EarthCARE cal/val activities. Moreover, ASKOS marks a turning point in our ability to study Saharan dust properties and the processes affecting its atmospheric transport, as well as the link to other components of the Earth's system, such as the effect of dust particles on cloud formation over the Eastern Atlantic and the effect of large and giant particles on radiation. This is possible through the synergy of diverse observations acquired during the experiment, which include intense 24/7 ground-based aerosol, cloud, wind, and radiation remote sensing measurements, and UAV-based aerosol in situ measurements within the Saharan air layer, up to 5.3 km altitude, offering particle size-distributions up to 40 µm as well as sample collection for mineralogical analysis. We provide an outline of the novel measurements along with the main scientific objectives of ASKOS. The campaign data will be publicly available by September of 2023 through the EVDC portal (ESA Validation Data Center). [ABSTRACT FROM AUTHOR]

Greece was hit by an extreme heat wave, with a significant impact on human health and natural ecosystems in the period between 28 July and 11 August 2021. After the end of this unusual warm period, a rare occasion of multiple supercell storms was observed on 11 August 2021 in northern and central Greece. The synoptic conditions indicated embedded short waves in a northwesterly flow and significant thermal instability across the regions of interest was evident. In conjunction with the strong vertical wind, shear organized convection was released. At least six long-track supercells were documented and the onset, evolution and specific characteristics of them are presented. All supercells moved from NW toward SE, accompanied by large hail, intense rainfall and destructive wind gusts, producing widespread damage along their track. [ABSTRACT FROM AUTHOR]

The selection of appropriate function forms linking the radar-based polarimetric variables and quantitative precipitation estimates (QPEs) is critical for the estimation of precipitation accurately. In this study, several functional forms using nonlinear optimization and artificial neural networks are evaluated. The polarimetric variables including radar reflectivity factor (ZH), differential reflectivity factor (ZDR), and specific differential propagation phase (KDP) values are obtained from an X-band multiparameter radar (XMPR) recently installed in a Yogyakarta region, Indonesia. The region experiences highly variable rainfall with mostly frontal rainfall events confined to December to March. Observed precipitation data available from a sparse rain network in this region is used for comparative evaluation of the rainfall rates. Rain gauge data for three years (2016-2018) are used for the assessment. Results from the analysis suggest that improved estimates of rainfall at finer temporal resolutions of 10 minutes can be obtained using functional forms developed with the optimization of polarimetric thresholds when adequate observed rainfall data and polarimetric variables are available. Furthermore, the use of the multiple linear, stepwise regression model and neural networks approach can measure the sensitivity of the functional forms used for rainfall rate estimates. Local models based on specific temporal windows (e.g., month or a season) can help improve the functional forms and therefore rainfall rate estimates. [ABSTRACT FROM AUTHOR]

In this study, the physical principles governing car-bfollowing (CF) behavior and their impact on traffic flow at signalized intersections are investigated. High temporal-resolution radar data is used to provide valuable insights into actual CF behavior, including acceleration, deceleration, and time headway distribution. Demandcalibrated SUMO simulations are run using empirical CF parameter distributions, and three CF models are evaluated: IDM, EIDM, and Krauss. By emulating radar data in SUMO and processing simulated vehicle traces, discrepancies between empirical and simulated parameter distributions are identified. Further analysis includes comparisons with default SUMO CF model parameters. The findings reveal that measured accelerations differ from CF model parameter accelerations and using the empirical value (µ = 0.89m/s2) leads to unrealistic simulations that fail volume-based calibration. Default parameters for all three models reasonably approximate the mean and median of measured parameters, but fail to capture the true distribution shape, partly due to homogeneity when using default parameters. The results show that it is more effective to simulate with the default parameters provided by SUMO rather than using measurements of real-world distributions without additional calibration. Future work will investigate closing the loop between the measured real-world and SUMO distributions using traditional calibration tactics, as well as assess the impact of calibrated vs. default CF parameters on simulation outputs like fuel consumption. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The readiness of military defense radar is absolute in effort to maintain Indonesia air sovereignty from potential threats that may enter and endanger the security of citizens and residents throughout Indonesia territory. Currently, the radar health condition monitoring system has not been integrated in a whole system integrated manner between the subsystems each other, it causes a relatively long time to identify critical failures that may arise in the related subsystems. Prognostics and health management (PHM) takes the current state of the system as a starting point, combined with structural characteristics, parameters, environmental conditions, and historical data of objects, to monitor the equipment working status with various knowledge, algorithms, and models based on advances in sensor acquisition technology. PHM on MASTER-T radar maintenance is proposed using the method of failure mode effect and criticality analysis (FMECA) which aims to predict critical failures, thus preventing fatal damage that can result in system breakdown. Predictive maintenance is added to conventional maintenance, thereby minimizing idle time when repairs must be made with the radar system inactive. The application of this method obtains a risk priority number (RPN) which is used as a reference in determining critical components that must be repaired immediately. [ABSTRACT FROM AUTHOR]

Detection of vehicle occupants' body and health conditions such as postures, breathing rate and heartbeat rate can be used to trigger situation specific safety measures just before, during and after a car accident. The detection of occupants' conditions often involves using different sensors that are installed in different locations inside the vehicle to cover the surrounding. Especially when the calculation uses fused data from the sensors, to obtain accurate results, all sensors should be intrinsically and extrinsically calibrated. As the data structure of different sensors are usually different, and sensors are usually installed in different locations with different orientations inside a vehicle compartment, extrinsic calibration of all sensors is usually complex and challenging. In this paper, we propose a method to estimate the pose of a multimodal setup with radars, RGB cameras and Timeof-Flight (ToF) cameras inside a vehicle compartment using only position markers (so-called ArUco markers). This method is illustrated in a vehicle mock-up. At first, the markers are mapped using a high-resolution external camera and one marker is chosen to be the vehicle origin reference. The optic sensors - 2D and the 3D ToF cameras, estimate their pose over the ArUcos detected in a single shot automatically. As the radar sensors do not detect the ArUco markers as a form of image, an ArUco marker is placed on the cover of the radar instead, and the transformation from the vehicle origin to the radar is determined from this. With a calibrated sensor setup, it is possible to evaluate algorithms based on radar data and 2D images referred to the 3D groundtruth data - which is the point cloud obtained from the ToF sensor. The experiments shown a maximum error in ArUco centers position of 1.79 cm and the maximum error of radar positions is 1.9 cm. [ABSTRACT FROM AUTHOR]

Recently, the number of systems based on FMCW radar technology has been increasing dramatically, due in part to the availability of low-cost development and evaluation kits that permit rapid prototyping and testing of radar-based applications. In a real scenario where it is possible to have multiple radars emitting simultaneously, interference between radars can arise due to the periodic nature of FMCW. Moreover, FMCW radars take advantage of the large bandwidth in order to achieve a high resolution in range. Therefore, the probability of two radars using the same spectrum range simultaneously is very high. In this work, the interference between FMCW radars systems is investigated using set theory. The FMCW signals are modeled as sets of time-frequency tuples and they are described as sets, reducing the analysis complexity of the interference between multiple radars. The proposed model was implemented in MATLAB and it was compared and validated in real scenarios with two radars operating and producing interference in the same indoor environment. It is shown that set theory considerable reduces the simulation time in comparison to traditional methods. [ABSTRACT FROM AUTHOR]

Due to the complex motion of a spatially distributed target, additional components of the radial velocity appear in its individual elements. This effect leads to the fact that the standard weighting function turns out to be unsuitable for adequate construction of radar images of such targets when observing by a synthetic aperture radar (SAR) technology. Individual points of the radar image of moving target may be located closer or further from each other than in the true undistorted image. This effect is analyzed in detail using an ambiguity function in this article. [ABSTRACT FROM AUTHOR]

In solving various problems of space monitoring, the problem arises of determining the presence or absence of small changes in the state of the reflecting surface during the observation session, as well as, of determining the characteristics of these changes, such as the position, size, and average power values of the reflected signals. The article is devoted to development of a method designed to detect such changes, and to the study of effectiveness of this method based on estimates of measurement errors. Spatial recommendations are given for implementation of this method based using the real scattering cross-section of an example region. [ABSTRACT FROM AUTHOR]

A study of the smoothing properties of the Frost speckle-noise filter on the simulated radar images was conducted. A variant of the filter modification is proposed, which allows significant reducing computational costs. Based on a comparative analysis of the filtration procedures, recommendations for the filter application to the radar image processing tasks are given. [ABSTRACT FROM AUTHOR]

Icebergs are considered as a danger to the navigation in cold waters. They cause a huge peril for seaward oil investigation, shipping, and undersea or sub-ocean pipelines. Synthetic aperture radar (SAR) is determined to be a valuable tool and more efficient for monitoring and detecting icebergs even in the cloud-covered polar domains and in dark regions. However, the distinguishing proof of little ice shelves is a difficult errand when these are installed in ocean. In this paper we examine and explain about different types of bands and their importance in icebergs detection in sea using polymerization. [ABSTRACT FROM AUTHOR]

Convective-stratiform rain classification is essential because these rainfall types have different physical characteristics. This work evaluates the use of Artificial Neural Network (ANN)-backpropagation to classify rainfall observed by Micro Rain Radar (MRR) at Serpong, Indonesia. Classification is based on radar reflectivity (Z), Doppler velocity, and Liquid Water Content (LWC). During April 14, 2016, and May 4, 2017, rain events were used as training and testing data, respectively. The best ANN-backpropagation architecture for rain classification is a 3-6-1 architecture (input layer-hidden layer-output layer) with a learning rate of 0.6 for convective rain and 0.9 for stratiform rain, respectively. The accuracy of convective and stratiform rain classification obtaining is 86.9565% and 100.0000%. Good accuracy was also found when the result was validated by the BB (Bright Band) method. Thus, the ANN- backpropagation method can classify the MRR data accurately. [ABSTRACT FROM AUTHOR]

Radar is a detection system that uses radio waves and depends on many parameters. The waveform of the transmitting signal represents an important factor in the detection processes. Therefore, the improvement of the waveform will tend to improve radar detection. This paper presents the double Golay cod 32-bits with a specific correlator. The merit factor (F), discrimination (D) of a complementary pair, and peak side lobe level (PSL) dose evaluates as the important factor for radar applications. A Stable merit factor of 0.5 and high discrimination factor infinity with zero peak side lobe level have been gained. [ABSTRACT FROM AUTHOR]

Clutter removal of marine radar for weather observation depends on the quality and consistency of clutter map. the clutter removal often become difficult since echoes from hard targets are much stronger than the rain reflection. There is also constraint due to different azimuth angle of each scan line in every scanner rotation resulting inconsistent map of clutter. The effort to obtain consistent clutter map to easily distinguish the rain echoes depends on the method of signal pre-processing and pulse integration. Oversampling factor influences the target detection result as higher value enable the radar to see large object more detail. The type of LPF determines the clarity of the radar image, thus better clutter map. While the pulse integration improves probability of detection and produces better clutter removal when the radar is applied for rain observation since it can provide much stable static clutter map. [ABSTRACT FROM AUTHOR]

This paper presents Millimetro, an ultra-low-power tag that can be localized at high accuracy over extended distances. We develop Millimetro in the context of autonomous driving to efficiently localize roadside infrastructure such as lane markers and road signs, even if obscured from view, where visual sensing fails. While RF-based localization offers a natural solution, current ultra-low-power localization systems struggle to operate accurately at extended ranges under strict latency requirements. Millimetro addresses this challenge by re-using existing automotive radars that operate at mmWave frequency where plentiful bandwidth is available to ensure high accuracy and low latency. We address the crucial free space path loss problem experienced by signals from the tag at mmWave bands by building upon Van Atta Arrays that retro-reflect incident energy back towards the transmitting radar with minimal loss and low power consumption. Our experimental results indoors and outdoors demonstrate a scalable system that operates at a desirable range (over 100 m), accuracy (centimeter-level), and ultra-low-power (< 3 uW). [ABSTRACT FROM AUTHOR]

We present DeepRadar, a novel deep-learning-based environmental sensing capability system for detecting radar signals and estimating their spectral occupancy. DeepRadar makes decisions in real-time and maintains continuous operability by adapting its computations based on the available computing resources. We thoroughly evaluate DeepRadar using a variety of test data at different signal-to-interference ratio (SIR) levels. Our evaluation results show that at 20 dB peak-to-average SIR, per MHz, DeepRadar detects radar signals with 99% accuracy and misses only less than 2 MHz, on average, while estimating their spectral occupancy. Our implementation of DeepRadar using a commercial-off-the-shelf software-defined radio also achieves a similarly high detection accuracy. [ABSTRACT FROM AUTHOR]

The paper is devoted to the development of a mathematical model of the terrain radar image created by the onboard radar. The model is based on the ray tracing method and takes into account the reflective properties of the surface using a special radar texture function The radar texture function is complex-valued function of the three 3D-vector arguments: a point of illuminated surface, a position of transmitter, a position of radiation receiver. This function describes amplitude and phase of reflected plane wave. The radar texture function is needed to simulate radar images formed in motion and to account for the reflective properties of various types of surfaces. The results of comparing the real radar image with the constructed model are also described. [ABSTRACT FROM AUTHOR]

As the spectrum demand increasing with time, so, the directivity and efficiency of antenna array now become a vital issue. Mostly, researchers have used a planar antenna array to get a high directive antenna with better performances. However, the planar array's gain is limited. It contributes high sidelobe levels and strong mutual coupling effects those need to overcome. In this paper, a new configuration of 4 elements circular equivalent planar array has been proposed to achieve high gain and directivity with lower sidelobe level. After being designed and simulated, the proposed antenna array has achieved high directivity of 15.3 dBi with 85 % radiation efficiency. Besides, the array has a maximum realized gain of 14.51 dB and low sidelobe level of – 15.1 dB. In turn, the high directivity of the proposed antenna array resonating at 5.8 GHz with very minimum return loss makes it suitable for Radar application. [ABSTRACT FROM AUTHOR]

The probabilities calculation of correct and incorrect surface changes recognition observed by radars placed on satellites is an actual task. In the paper, analytical expressions for calculating the efficiency of classification based on the Chernoff and Kailath boundary ratios, are obtained. The expressions are illustrated by a number of practically useful examples of detecting and recognizing the changes in the radar image. [ABSTRACT FROM AUTHOR]

While solving different problems of space monitoring, the problem of determining the presence or absence of the small changes of the reflecting surface arises during the observation session. For reliable detection of such a situation, it is recommended to use a constellation of small satellites that form statistically independent radar images. In the paper, we investigate the algorithm for classification of the signals reflected from two surfaces with different values of scattering cross-section on the set of radar images. The analytical method and the statistical simulation method are investigated, and the behavior of probabilities is examined when the magnitude of changes on the surface are varies. The recommendations are given on the choice of the number of satellites for various characteristics of reflective surfaces. [ABSTRACT FROM AUTHOR]