Primary Radar Systems Research Articles

Comparative analysis of the quality of detection of air objects by secondary radar systems

The work is devoted to a comparative analysis of the quality of detection of air objects by secondary radar systems. The purpose of the work is a comparative analysis of the optimal and quasi-optimal structure for detecting air objects by secondary interrogation radar systems. A significant role in the information support of the airspace control and air traffic control system is played by secondary radar systems for airspace surveillance, which include secondary radars and identification problems on the basis of “friend or foe” identification. Note that in existing networks of radar surveillance systems, tracking of airborne objects is usually carried out using information from primary radar surveillance systems, and secondary radar surveillance systems are used as sources of additional radar information. In this regard, the problems of assessing the quality of detection of air objects by secondary radar systems, the specifics of the construction and operation of which differ significantly from the primary airspace surveillance radar systems, are relevant. Thus, increasing the probabilistic characteristics of the system of secondary radar systems when an aircraft transponder operates in the field of significant flows of intentional and intra-system interference is ensured by choosing detection thresholds depending on the values of the transponder readiness coefficient and the probability of suppression of individual response signal pulses. On the other hand, the use of detection thresholds on secondary radar systems that are optimal for the given operating conditions of the transponder makes it possible to reduce the requirements for the throughput of the aircraft transponder with a significant intensity of flows of intra-system and intentional correlated interference. Analysis of the characteristics of detection of air objects by secondary radar systems shows that: optimal thresholds for detecting air objects in secondary radar systems significantly depend on the readiness factor of the aircraft transponder and the probability of suppression of individual pulses of response signals in the response channel; the use of decoding response signals and subsequent accumulation when choosing the optimal threshold significantly reduces the detection quality indicators compared to optimal processing of a burst of response signals; the digital threshold for detecting air objects in a secondary radar system largely depends on the probability of signal suppression in the request channel and response channel.

Synthesis and analysis of the trace detector of air objects of an interrogating radar system

The paper considers the features of tracking air objects in existing information networks of radar systems for monitoring airspace. It is shown that the tracking is carried out according to the information of the primary radar surveillance systems, and the secondary radar surveillance systems are used as sources of additional radar information. But the transition to automatic dependent surveillance implies the mandatory use of only request radar surveillance systems. Therefore, the problems of formulating methods and algorithms for tracking air objects based on information from secondary radar surveillance systems are relevant. The specifics of the construction and operation of secondary radar surveillance systems differ significantly from primary radar surveillance systems. The work carried out the synthesis and analysis of the structure of the tracks detector of air objects by interrogating radar systems for monitoring the airspace, namely: a comparative analysis of the quality of identifying the tracks of air objects was carried out; the quality of information support to consumers of the airspace control system with the proposed structure was improved in comparison with the used information processing structure; it is shown that the quality of information support for consumers has more preferable indicators when using the signal processing method during acquisition with subsequent information merging; the influence of the readiness factor of aircraft transponders of interrogative radar systems on the quality of information support for consumers of the airspace control system was evaluated.

Method for increasing noise immunity of radar "friend or foe" identification systems under the action of intentional correlated interference

The paper analyzes the principles of construction and structure of "friend or foe" identification systems. It is revealed, that the party, interested in the existing system, has the ability of unauthorized use of this information resource for long-range determination of air objects coordinates, on the one hand, and distortion of information of this information resource, on the other hand, which leads to unpredictable consequences. It is shown, that the most vulnerable place in the "friend or foe" identification systems is the aircraft transponder, which significantly affects noise stability and noise immunity of the identification systems of air objects. The paper proposes a method of hereditary transition to noise-immune "friend or foe" identification systems based on synchronous networks of identification systems, which allows expanding significantly the methods of servicing requests and methods of constructing systems. This method of constructing identification systems eliminates the existing problem of dispersed identification systems, as well as the problem of temporal matching of signals coming from primary and secondary radar systems. The proposed method of hereditary transition to noise-immune "friend or foe" identification systems makes it possible to exclude the possibility of unauthorized access to identification information resources by an interested party, significantly increases the noise immunity of the identification system as a whole.

ASSESSMENT OF THE QUALITY OF INFORMATION SUPPORT BY AIR RADAR SURVEILLANCE SYSTEMS

The paper pays attention to the consideration of the structure of user's information support of the airspace control system at the stage of primary information processing by the joined radar system. This system includes a primary and identification surveillance system, which allows considering the overall structure as a single synchronous network of surveillance information systems. Such a structure can be characterized by an overall integrated quality indicator of the information support of the airspace control system. Such a quality indicator can be the probability of information support, which is the product of the probabilities of correct detection of an air object by the primary radar and identification system on the basis of "friend-foe" and the probability of comparing the coordinate information of primary radar systems and identification systems. This approach allows changing the model of combining information for primary radar systems and identification systems so as to take into account the estimated coordinates of the air object by both information systems due to the weight combination of coordinates of air objects. The calculation of the coordinates of air objects according to the information of the primary radar systems and identification systems allows improving the quality of information support for decision makers in the air traffic control system.

Особенности патентного анализа радиолокационных систем различного назначения с использованием ресурсов патентного ведомства США

The patent documentation is one of the main information sources for forecasting the development of various technical (technological) areas. This paper examines the features of radar systems development with the use of the US Patent and Trademark Office resources. In this study, the data concerning the dynamics of USA invention patents registration for ten-year period (2010-2019) have been found for G01S13 (“Radar systems”) group of the International Patent Classification. The results obtained confirm the significant progress achieved in the development of the systems using the reflection or reradiation of radio waves in specific practical applications. In particular, the inventions intended for using in space (“space”), airspace (“air”), as well as in ground and surface (“surface”) systems. It is shown that during the last ten years the systems using reflection of radio waves (“primary radar systems”) and radar systems, specially adapted for specific applications, have demonstrated the best dynamics in their development. As a result of the data analysis, it is concluded that the radar systems, specially adapted for such specific applications as anti-collision purposes, radar systems for such specific applications, and primary radar systems, should be considered as the most promising in the next two to three years.

A portable primary radar for general aviation.

A detailed situation awareness of the local environment is essential for safe flight in General Aviation. When operating under Visual Flight Rules, eyesight is crucial for maintaining situation awareness and objects may be overlooked. Technical solutions such as Flarm have been sought, but they only work on a basis of co-operation: obstacles without the proper equipment are invisible. Recent developments in the field of radar technology, partly empowered by the demand for sensors for autonomous cars, have improved the size and power consumption of available hardware. Today, the hardware exists to build a portable primary radar system for situation awareness. In this paper the results are presented of efforts to build the first portable primary radar for general, which has to be lightweight, cheap and have a low power consumption. The focus in this paper is on the software design of such a radar system. The physical principles of radar sensing are described, as well as the scientific steps needed to provide situation awareness. The hardware and software for the radar are both built and tested, and the results of these tests are presented. A flight experiment is performed with a small aircraft flying past a stationary radar on a small hill. It is found that the radar is capable of detecting the aircraft up to a distance of at least 3 kilometers. 3D localization is performed and the location determined by the radar was on average 46 meters away from the aircraft position as measured by satellite navigation, relative to a total distance of about 1000 meters from the radar. A low-pass filter can be applied on the raw results in order to improve the location estimation further. Future research will focus on bringing the portable radar in motion while operating.

An ultra-wideband 6–14 GHz frequency modulated continuous wave primary radar with 3 cm range resolution

This paper describes the design and verification of an ultra-wideband 6–14 GHz frequency modulated continuous wave (FMCW) primary radar system with very high range resolution. The design and measurement results of the utilized signal generator and receiver are presented. The signal generator features a 86% relative continuous tuning range and average phase noise of −106 dBc/Hz at 1 MHz offset to the carrier. The radar system utilizes a hybrid structure where the voltage controlled oscillator was fabricated using 130 nm SiGe BiCMOS technology and the lower frequency components are off-the-shelf. Free field measurements of the radar showcase an unprecedented combination of 3 cm range resolution, low phase noise and low operating frequency of 6–14 GHz for inherently higher range.

An Efficient Ultrawideband Pulse Transmitter With Automatic On–Off Functionality for Primary Radar Systems

This letter proposes an ultrawideband (UWB) transmitter for a UWB primary impulse radar that is designed for real-time pedestrian localization. The proposed transmitter applies a novel combination of a UWB pulse generator followed by a UWB amplifier to boost output pulse amplitude, which is able to be turned off automatically after one pulse transmission in order to reduce power consumption. The transmitter has been fabricated using 45-nm SOI CMOS technology and has been measured on a printed circuit board (PCB). The produced pulses possess a high measured peak-to-peak amplitude of 425 mV and a width of around 600 ps. The power spectral density (PSD) of the pulse achieves a maximum of −41 dBm/MHz at 6 GHz with a −10-dB bandwidth of 4.5 GHz from 3.3 to 7.8 GHz that assures that the proposed transmitter complies with the regulation of the U.S. Federal Communications Commission (FCC) for UWB outdoor applications. The pulse generator consumes around 10 pJ/pulse from a 1-V supply, which is very low among the similar designs, and remains almost constant with an increasing pulse repetition time (PRT).

Clutter and distortion products suppression methods for code division multiple access systems

This study summarises effort to design and optimise clutter and distortion products suppression method for multi-static primary surveillance radar (MSPSR) system working with code division multiple access. Proposed methods have been designed based on clutter suppression algorithm used in frequency division multiple access systems with an emphasis on computational complexity. Further research has been focused on suppression and also other distortion products in a received signal, those are mostly caused by the phase noise of transmitters and receiver. Finally, the optimal setting of designed methods has been investigated, which is mainly focused on orthogonalisation process of base matrices and time frame length for clutter suppression. Performance of proposed algorithms is compared on both simulated and real signal from the MSPSR system and also for numerical precision single versus double.

SASS-C processing capability of MSPSR data

Abstract The main objective of this expertise was to examine if Surveillance Analysis and Support System for ATC Centre (SASS-C) verification tool is interoperable with currently implemented Multi-Static Primary Surveillance Radar (MSPSR) and Passive Surveillance System (PSS) technologies as well as with type of data that are delivered by them. In case of SASS-C is not interoperable to work with MSPSR/ PSS data yet, the task is to suggest appropriate solutions and suggestions for verif Opportunity Traffic Reconstructor (OTR) algorithm to use these values with an appropriate level of confidence. Our research was focused to simulation of the data and data handling of different sensor systems now and in the future. We are expecting new technologies (MSPSR and PSS systems) to become widely used as the base stone of the surveillance in the coming years. The whole expertise was done in European Organisation for the Safety of Air Navigation (EUROCONTROL), Brussels in cooperation of Surveillance Services Department, SASS-C team with the University of Zilina, Air Transport Department. The article describes whole expertise and offer to the reader guide how to simulate pure MSPSR and PSS data in SASS-C VERIF tool. The whole simulation is based on modifications done on the existing datasets obtained from multilateration (MLAT) sensors. In our experiment we used datasets provided by Air Navigation services of Czech Republic (CZ ANS). All modifications, which have been done, are described in this document as well as suggestions, outcomes and conclusions of the analysis.

Modeling and Simulation of a Ground Based Sense and Avoid Architecture for Unmanned Aircraft System Operations

The safe operation of Unmanned Aircraft Systems (UAS) in the National Airspace System necessitates a capability to sense and avoid other airborne objects. One solution is a Ground Based Sense and Avoid (GBSAA) concept, where data from ground-based radars are fused in a specially tuned tracking system that can provide traffic information to manual (flight crews) or automatic collision avoidance systems. In this paper, we will present a modeling and simulation approach to assess site-specific radar detection and tracking performance. High fidelity primary surveillance radar and tracking system models enable simulation studies to determine target probability of detection and distributions of expected track initiation times across the surveillance volume. Atmospheric and environmental conditions, terrain, and land coverage type affect radar wave propagation. Models take into account these sources of degradation, as well as target characteristics, site-specific radar performance, tracking system filtering, and initiation logic. This information will help in developing a GBSAA concept of operation, mission planning, and will ultimately define where UAS can operate with sufficient surveillance performance to meet sense and avoid requirements.

Review of United Kingdom Radar

A review of primary radar systems in the United Kingdom that have recently entered service or are at an advanced stage of development is presented. Naval, airborne, and land-based types are all discussed covering both civil and military interests, although particular emphasis is given to airborne equiipments. Some general supporting radar technology includini! titiversity programs is also covered.

New commutated Doppler radar system

A new design for a double-sideband commutated Doppler primary radar system for detecting a target is proposed. Target information is obtained by the measurement of various Doppler frequencies, and a unique feature of the system is its combined use of frequency diversity, space diversity and time diversity to achieve a better overall performance.

Marine Radar Beacons

In this paper the author sketches the historical development of radar beacons: the different types are classified in relation to code and frequency employed and the benefits and drawbacks of more recently proposed types of beacon are discussed.The paper was presented at a Marine Electronics Symposium sponsored by the Society of Electronic and Radio Technicians at the University of Southampton in July 1976.The military use of responder beacons before 1945 led to secondary radar systems, such as Rebecca-Eureka, Oboe, and IFF, giving facilities for target location at long range with an accuracy and identification not available from a primary radar system. The desirability of these advantages in civilian systems was recognized but the absence of military urgency and considerations of cost led to delay. Although responder beacons became an essential part of the Air Traffic Control System, extension into the marine field did not succeed until the U.K. Ministry of Transport Safety of Navigation Committee set up a Technical Committee and Working Party in 1962 to investigate the conditions governing the marine installation of responder beacons as a navigational aid. This committee recommended that responder beacons (alternatively called racons) should be set up to an agreed specification at selected sites around the UK coast, to become the first civil marine navigational racon system. The co-operation of the Admiralty Surface Weapons Establishment, Trinity House, and Kelvin Hughes made possible the installation and operation of three racons—on the Liverpool Bar LV, the Kish LV, and St. Abb's Head LH—to provide operational experience on which the committee's recommendations were based, followed by the setting up of the complete system.

Digital control for primary radar systems

An investigation into the use of digital logic techniques for simple pulsemodulated radar systems resulted in their application to provide the necessary controlling and timing waveforms for a display. The paper describes a conventional analogue display and its digital counterpart and compares both systems. Results for the performance of a logic system are given.

Studies of a twin-channel frequency-modulated echo-location system

This paper describes theoretical and experimental studies of a proposed twin-channel echo-location system using frequency-modulated transmissions, in terms of its possible application to primary-radar systems or target-tracking systems. The proposed system can measure the range and bearing of a target from a fixed aerial system, although in the presence of multiple targets, ambiguities of target position restrict its performance. The system may be adapted, however, for accurate tracking of a target containing a suitable signal source.

The Theory and Application of the Radar Beacon

Part I discusses the general theory underlying the operation of radar beacons. The various components of a typical beacon, such as the receiver, discriminator, blanking gate, coder, modulator-driver, modulator, transmitter, stabilizing tuner, antenna, and monitor, are discussed in some detail. System considerations, such as the comparison of primary and secondary radar systems, delay in the beacon, factors governing the choice of beacon transmitter and receiver frequencies, system accuracy, duty cycle and traffic-handling capacity, and siting and range, are discussed. Part II considers the application of the radar beacon to identification, air and ground-controlled general navigation, air and ground-controlled precision navigation, collision warning, emergency rescue, field-strength measurement, and airport-approach control.