The paper examines the existing systems of radar identification based on the "friend-foe" feature from the point of view of immunity evaluation. Currently, there are two systems of the radar identification based on the characteristic of "friend-foe", namely, the "Password" and MkXIIA. They are the radar identification systems based on the "home-foreign" feature. The former of the specified systems operates in a frequency range that differs from the frequency range of secondary radar systems, while the second one operates in the frequency range of secondary radar. These systems are ones of the main information resources of the airspace control system and are built on the principles of a one-channel or two-channel information transmission system. It allows the interested party, both an unauthorized use of this information resource for remote determination of the coordinates of aerial objects, on the one hand, and twisting the information of these information resources, on the other hand, which leads to unpredictable results. The purpose of the work is to assess the immunity of existing radar identification systems based on the "friend-foe" feature. The analysis of the interference protection of existing systems for the object radar identification based on the "friend-foe" feature, built on the principles of interrogative and non-interrogative information systems presented in this work, showed that the use of rectangular radio signals with time-pulse modulation as request and response signals emitting by air objects, has low immunity and excludes the energy stealthiest of the respondents of aerial objects. And, as a result, it allows for unauthorized calculation of the coordinates of air objects by the interested party based on the emitted identification signals on the basis of "friend-foe".
The presented paper examines the principles and methods for processing of information from airspace surveillance radar networks. Information technologies allow implementing automatic collection, processing, storage, transmission and issuance of radar information to users. In this work, the synthesis and analysis of the optimal structure of the interstage processing of signal data and radar information of primary processing in the network of airspace surveillance radar systems is carried out. The quality of information from radar networks of airspace surveillance systems affects almost all indicators of the quality of the radar systems network functioning. The stages of radar information processing in radar systems networks are analyzed. The importance of specifying the above stages for creating a complete picture of the air situation in the area of responsibility is shown. To improve the quality of information support for consumers, a network of radar systems requires information processing at all stages. At each stage of information processing, information processing quality indicators were analyzed. This made it possible to show that the staged implementation of information processing, on the one hand, simplified the optimization of processing within each processing stage, but on the other hand, it made it difficult to carry out compatible optimization of both the detection of an aerial object and the measurement of the coordinates of an aerial object. The synthesized structure of processing radar information of the network of radar systems of airspace surveillance, which in its turn made it possible to carry out interstage optimization of processing of both signal data and primary processing information. Calculations have shown that the method of information processing, in which the combination of information is carried out at the level of decision-making on the detection of airborne objects in each signal data processing channel, has some advantages in the quality of information processing of the network of radar systems compared to the one currently used. time option combination information at the stage of signal processing. At the same time, for the method of combining information at the level of decision-making about the detection of aerial objects, the flow of transmitted information to the joint processing point is significantly reduced. All this allows improving the quality of information processing in the airspace control system.
Secondary radar systems for monitoring airspace play a significant role in the information support of airspace control systems and air traffic control. These systems provide radar surveillance of airborne objects equipped with aircraft transponders and provide two-way communication via data request and response channels between ground radar stations and airborne objects. The paper assesses the relative throughput of aircraft transponders of secondary radar systems for monitoring airspace under the influence of correlated and uncorrelated interference in the request channel. The assessment of the throughput of the aircraft transponder shows that the aircraft transponder does not reach the maximum load included in the existing identification system under the influence of deliberate correlated interference. This indicates a sub-optimal determination of the aircraft transponder load factor of the existing secondary radar system. Incorrect determination of the maximum load of the aircraft transponder leads to a decrease in the noise immunity of both the aircraft transponder and the entire secondary radar system. At the same time, it should be noted that the interested party has the possibility of unauthorized use of an aircraft transponder to obtain information or paralyze the latter when applying interference of the required intensity.
The presented work considers the place and role of wide-area multi-position airspace surveillance in the information support of airspace control and air traffic control systems. Classification of methods for estimating the coordinates of air objects using various primary measurements of the parameters of received signals in multi-position observation is given. A quantitative assessment of the accuracy in determining the air objects’ coordinates by the considered methods is also given. The capabilities of wide-area multi-position surveillance systems increase significantly when using the principles of constructing a secondary surveillance radar as a non-synchronous network, and an aircraft responder as an open single-channel queuing system with servicing the first correctly received request signal. An unauthorized request from an aircraft responder makes it possible to switch from completely passive methods for detecting and determining the coordinates of an air object to active-passive ones, which provide an increase in the accuracy of solving a coordinate task by dozens of times while maintaining the energy secrecy of a wide-area multi-position observation system. It is shown that the use of active and passive methods for constructing wide-area multi-position observation systems makes it possible to implement goniometric, difference-range, goniometer-range, total-range and goniometer-total-range methods for determining the coordinates of an air object. This increases significantly the number of options for estimating the coordinates of an air object. As a result, it allows improving the quality of information support for users by choosing the optimal method for estimating the coordinates of the observed air objects using various primary measurements of the received signals parameters.
This paper presents the conducted assessment of noise immunity of the request signal transmission channel and response channel for flight information of secondary radar systems as part of aircraft responders. The considered system is an open single-channel queuing system with refusing due to the action in the request channel of intentional and unintentional correlated and uncorrelated (intra-system) interference and ground-based receivers that receive, process and decode flight information in the presence of fluctuation and intra-system interference in the receiving channel. The results of assessing the noise immunity of the aircraft responder in the form of the aircraft responder’s readiness factor under the action of internal and deliberate interference are given. It is shown that the principle of constructing an aircraft responder and the principle of servicing request signals and transmitting flight information do not allow ensuring acceptable probabilities of obtaining flight data at ground control points.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.