Range Radar Systems Research Articles

Water penetrating radar: A fluvial scour study of antenna performance and data processing

AbstractGround‐penetrating radar (syn. water‐penetrating radar, or WPR hereon) has been used previously in the detection and characterisation of riverine scour. This paper presents field data, equipment calibration and processing output results from a new generation of high dynamic range (HDR) radar systems. These provide a new and more sophisticated model of fluvial scour for the study site. The adaptability for deployment on water, wide bandwidth and good quality in raw and processed data, demonstrates the advantages of the system. Data processing and depth calibration are issues in the interpretation of WPR data, which are both discussed. WPR demonstrates the potential for surveying sedimentation where palaeoscour occurred and thus anticipated. This maybe in conjunction with other techniques or where aquatic vegetation, rocky substrates or methane gas bubble release preclude use of sonar.

Method of increasing the range resolution of radio pulse sensors of short-range radar systems

The description of a new method for increasing the resolution of radio pulse sensors (RPS) designed for short- range radar systems (SRRS) for detecting and measuring motion parameters of location objects is presented. The essence of the method is that the controlled area of space with the targets located in it is periodically irradiated with probing radio pulses, and during their radiation, radio pulses reflected from the targets are simultaneously received and divided into two quadrature channels. Next, they are mixed with probing radio pulses, and the time-overlapping parts of these radio pulses are converted into the region of low Doppler frequencies in the form of two quadrature video pulses. Then, the quadrature video pulses received in these channels are sampled by amplitude, stored at multiple points in time and digitally processed according to the proposed algorithm. The method is implemented in the RPS made on the basis of a horn-lens antenna, a Doppler receiving and transmitting module with quadrature outputs of converted signals, a synchronization and pulse generation unit, as well as a digital signal processing unit. The RPS can be used in onboard (for example, automotive) SRRS designed to detect moving targets, measure the distance to them, as well as determine the speed and direction of movement. The results of experimental studies have been obtained on the example of the 8-mm autodyne RPS made on the basis of the oscillator on a planar Gann-diode.

Frequency Source Design of Fast Locking Laser Range Radar

Given the bad ranging precision in continuous wave laser range radar systems because of the large jitter of the main oscillator frequency source, this paper introduces the fast locking method, which is based on Field Programmable Gate Array (FPGA) and modified mixed Charge Pump Phase Locked Loop (CPPLL), effectively improving the locking time of PLL frequency source. The input frequency is generated by a temperature compensation quartz crystal oscillator with high stability frequency (TCXO). It improves the PLL performance using the two-order active filter, reduces the phase detector dead-banding, and improves the frequency stability through the buffer insertion in PFD. The traditional PLL was improved by using preset voltage mode, which improves the PLL lock time. Finally, it analyzes the influence of frequency stability on the ranging accuracy of laser radar. The test results show that PLL lock time is up to 1.6ms. It can be applied to continuous wave laser radar ranging systems.

Results of research in the field of remote sensing methods for detecting oil pollution on the water surface conducted at the RSHU

The article presents the scientific results which are a generalization of almost twenty years of experience of the staff of the department of information technology and security systems of the Russian State Hydrometeorological University in the field of remote sensing methods of oil pollution on the water surface. The choice of radar systems for the implementation of remote monitoring of the water surface on the characteristics of efficiency and coverage of the area of responsibility is substantiated. Structurally, the radar monitoring system should consist of a network of centimeter and millimeter range radar systems. The use of centimeter-range radar systems is due to the preservation of their operability during intense precipitation. Millimeter-wave radar systems are characterized by higher radar contrast, which significantly increases the effectiveness of environmental monitoring of water areas, their performance depending on the weather conditions. Thus, a combination of radars of two ranges allows continuous monitoring of the water area in any weather conditions. Radar systems are a recording module as part of an object monitoring system. The facility monitoring system, in addition to existing systems at the regional level, allows to receive information on the environmental situation promptly. This is especially true in case of emergency situations that occur during loading and transportation of oil products and other environmentally hazardous substances. The most significant result of many years of research is the concept of an automated distributed system for remote environmental monitoring of the water surface. For each module of the system, methods and models for processing spatial data and algorithms for the distribution of measuring instruments in the monitoring space are proposed. The purpose of the functioning of such a system is associated with detecting oil spills on the water surface, monitoring the dynamics of pollution and predicting the development of emergencies resulting from environmental disasters. International cooperation in the field of environmental protection is shown to be international in nature, the joint projects being an effective tool for development of scientific and educational potential of higher education in the field of ecology. Participation in international projects not only allows to increase the scientific and educational potential of higher education, but also influences the formation of environmental policy

On the Use of Glint-Doppler-Azimuth Correlation for Speed Estimation of Nearby Tangential Targets

This article introduces a new radar architecture, which implements a new signal processing scheme, with applications to the Intelligent Transportation Systems. The proposed solution exploits a well-known problem regarding low range radar systems, the Glint Effect, in order to improve previous results. For that purpose, the presented system is required to measure azimuth and Doppler of targets, for which it opts for a 2-channel Digital Array Receiver scheme working with a frequency-modulated continuous wave. This involves more complex hardware and signal processing software, comparing to the common mono-channel non coherent systems, nevertheless latest devices (radio frequency subsystems, field-programmable gate arrays, digitizers, etc) make it simple and affordable. The proposed system, with an easy-and-fast side-looking installation, exploits several advantages of its 2-channel synchronous architecture (e.g. clutter cancellation, Doppler history availability, etc) to achieve a better estimation of two key measurements: traffic flow (instantaneous and average) and vehicles speed.

K‐band low‐power dual‐hybrid‐coupling quadrature voltage‐controlled oscillator

A low-power and low phase noise quadrature voltage-controlled oscillator (QVCO) is presented for short range radar systems here. A dual-hybrid coupling (DHC) technique is adopted to increase the output voltage swing. The second harmonic filters are applied to eliminate the phase noise as well as to suppress the phase error. The proposed DHC-QVCO was implemented with a low cost standard 0.18 μm complementary metal-oxide-semiconductor (CMOS) process technology. The oscillation frequency is operated between 19.8 and 21.5 GHz. The tuning range is 8.5%. The phase noise achieves −100.1 dBc/Hz at 1 MHz offset from a carrier frequency of 20.6 GHz. The phase error and gain error are 4.29° and 3.2 dBm, respectively. The core circuit consumes only 5.15 mW from a power supply of 1.5 V. The designed DHC-QVCO has demonstrated the advantages of low-power, low phase noise, and wide tuning range for K-band applications.

A road map to the detection performance of LFM-PC search radars with CFAR detectors

Pulse Compression (PC) radars are used to resolve the problem of designing long range radar systems with excellent range resolution. PC provides radar system with additional processing gain that enhances its detection capability. Among the different types of pulse compression waveforms, Linear Frequency Modulated (LFM) signals are the most tolerant to high Doppler shifts. This is why LFM-PC radars are widely utilized with high speed targets. However, the literature lacks a complete mathematical or simulation model to evaluate the its detection performance. This paper introduces a typical simulation model for search radar that is verified mathematically. The proposed model includes matched filter (MF), moving target detector (MTD), two different constant false alarm rate (CFAR) algorithms and LFM signal sidelobes on radar detection are to be considered. Two simulation models are introduced. Firstly, the Matlab simulation is introduced to verify the mathematical model and the theory. Secondly, the SystemVue simulation is applied to be used in the future work with the hardware in the loop facility.

Design of High Gain Novel Dielectric Resonator Antenna Array for 24 GHz Short Range Radar Systems

in this work we present a 16x1 array’ elements of a high gain Novel shape designed Dielectric Resonator Antenna (NDRA), having a low dielectric constant value of 18, for wide band (WB) and narow band (NB) 24 GHz automotive Short Range Radar (SRR) applications. The proposed NDRA array is feed by an efficient microstrip network feeding mechanism and presents wide impedance bandwidth (426 MHz), high gain (20.9 dBi), high efficiency (96%) and directional radiation pattern at 24 GHz with narrow angular beam-width of 6.4°. Computed NDRA array results allow the proposed design to be practical for the next automotive radar generations. Parametric studies have been analyzed using the Finite Difference Time Domain (FDTD) method of the CST-MW time domain solver and results, of the optimal structure, have been validated by the Finite Element Method (FEM) used in HFSS electromagnetic (EM) simulator.

Interview

Dr Yongjin Kim of Inha Technical College, Korea, talks about the work behind the paper ‘Design of transparent multilayer film antenna for wireless communication’, page 12. Dr Yongjin Kim I received my B.S. degree in electrical engineering from Inha University in Inchon, and my M.S. and Ph.D. from Ohio State University, Columbus. During graduate school, in the ElectroScience Laboratory at Ohio, I joined several projects involving design of conformal antennas, subsurface target detection/identification, ground bound reduction for outdoor range measurement and radar systems. Then, from 2003 to 2007, I was a senior engineer in the communication and networking laboratory at the Samsung Advanced Institute of Technology in Korea, where I conducted research into the design of various antennas for communication devices, including cellular phones and UWB and RFID antennas. Since then, I have been an associate professor at Inha Technical College. My principle area of research is the design of modern communication antennas and my current interests include a smart antenna system and the development of conductive file antennas with composite materials and structures. A variety of studies using transparent electrodes and transparent conductive films have been conducted in RF applications. If the RF performance of a transparent antenna can be made similar to that of a conventional antenna, a wide range of applications in wireless communication become possible, including for the Internet of things (IoT) and RFID. I was interested in the study of this idea and I thought it could lead to a breakthrough in the antenna field. In the paper, we propose a multilayer thin film antenna for mobile devices. The proposed antenna consists of an IZTO/Ag/IZTO multilayer film that is fabricated on polyimide substrate and a copper layer. The center frequency of the antenna is 1260 MHz. The proposed antenna using an IZTO (indium zinc tin oxide) electrode has an excellent resistive characteristic and high flexibility. Also, it shows a transmittance of 86%. The proposed antenna is made by inserting a thin Ag layer between two layers of IZTO. We placed the IZTO/Ag/IZTO 3-layer structure over a polyamide substrate. The antenna is designed as an IFA type structure with a coupled loop and two branches. Our antenna has very high transparency and good radiation efficiency, showing an excellent balance with regard to the trade-off between the two. It is also the first antenna model for a mobile hand set using an IZTO/Ag/IZTO 3-layer structure. I think this will be a good basis of research for the future development of the transparent antenna. Of course, the strength of transparent antennas is transparency, they can be attached to many kinds of objects requiring antennas, including TVs, cellular phone displays, automobile glass, etc; and for RFID and IoT applications, where making the antenna inconspicuous may be desirable for a range of different reasons. The interest for transparent wireless communication devices is increasing due to the demands from a variety of designs and developments in communication services, both from the perspective of visual design and being able to integrate device components more efficiently. Thus, I think the research into transparent electronic components and materials will continue. There are several challenges in this research. One of them is the fine manufacturing process, which is a key point of determining antenna performance. The next one is increasing the conductivity of the 3-layer structure without decreasing the transparency of the antenna. There is also a simulation modelling issue for designing the antenna structure. In the transparent and flexible antenna area, one of my related projects is in the use of composite materials of carbon nanotube and other polymer materials such as a poly-vinylidence fluoridle for antenna applications.

Improved sliding window detector in UWB-SRR system for vehicular applications

A novel ultra-wideband short range radar (UWB-SRR) system for measuring a target maximum range of 15 m and relative velocity of 150 km/h is proposed. The conventional detector has less detection performance if the reflected echo signals from the target are more distributed because the detection performance depends on a particular range bin only. However, the proposed detector's detection performance is increased when the reflected echo signals from the target are combined using the proposed sliding window. According to the presented simulation and theoretical analysis, the proposed detector is superior to conventional detectors when the target echo signal is more distributed against a background of additive white Gaussian noise.

Explicit expressions for debiased statistics of 3D converted measurements

The method for tracking based on Kalman filter with debiased consistent converted 2D measurements was given and discussed by D. Lerro et al. (1993) and Y. Bar-Shalom et al. (1993). In this work explicit expressions for debiasing compensation terms and debiased covariance statistics related to the 3D case are presented. The proposed procedure can be employed in active sonar systems or long range radar systems especially when the cross-range errors are significantly large relative to the range errors.

Millimeter wave backscatter measurements in support of collision avoidance applications

Millimeter-wave short range radar systems have unique advantages in surface navigation applications, such as military vehicle mobility, aircraft landing assistance, and automotive collision avoidance. In collision avoidance applications, characterization of clutter due to terrain and roadside objects is necessary in order to maximize the signal-to-clutter ratio (SCR) and to minimize false alarms. The results of two types of radar cross section (RCS) measurements at 95 GHz are reported in this paper. The first set of measurements presents data on the normalized RCS (NRCS) as well as clutter distributions of various terrain types at low grazing angles of 5° and 7.5°. The second set of measurements presents RCS data and statistics on various types of roadside objects, such as metallic and wooden sign posts. These results are expected to be useful for designers of short-range millimeter-wave collision avoidance radar systems.

Frequency stability of RF-excited CO/sub 2/ waveguide lasers in gain-switched and Q-switched regimes

The behavior of an RF-excited waveguide laser is analyzed in a gain-switched and a Q-switched regime measuring the frequency sweep during the optical pulse. This enables laser-induced medium perturbations (LIMP) to be directly distinguished from the effects of the discharge power loading. The experimental observations confirm that the main perturbation in the laser output frequency is to be attributed to thermal energy variations. This gives the result of a Q-switch chirp more than one order of magnitude smaller than in the pulsed current mode, suggesting the use of Q-switching waveguide lasers in applications such as long range or Doppler laser radar systems. The chirp behavior in the pulsed current mode can show overshot relaxation corresponding to the propagation of density waves in the guide. >