MILITARY THOUGHT No. 6/1990, pp. 16-20
Troop control
Captain 1st rankA. S. TITOV
The SUCCESS of the naval forces in conducting combat operations to repel enemy aggression and deliver retaliatory strikes is largely determined by the effectiveness of the functioning of radio-electronic means and systems (RES), without which, in modern conditions, it is impossible to control forces or use their weapons. However, the intensive equipping of ships and vessels, aircraft and submarines, control systems and support for various types of radio electronic equipment and purposes has greatly complicated the problem of their electronic protection.
The operational-tactical need for the integrated use of radio electronic devices of various types and purposes in the same areas at the same time and at the same or close frequencies leads to the occurrence of unintentional interference (IJM), when electromagnetic emissions from one means make it difficult or impossible to use other means (systems). The creation of the NRP is also facilitated by the desire to increase the radiated power of the transmitting and receiving devices of the REM in order to increase the resistance to the effects of enemy electronic warfare.
The importance of protecting the RES from unintentional interference, the magnitude of this problem led to the objective need to single it out as an independent task - ensuring electromagnetic compatibility (EMC) of radio electronic equipment. The practice of using RES of ships, formations and formations in exercises, as well as the experience of local wars, confirmed the relevance and difficulty of solving this problem.
An example of the complexity of RES electromagnetic compatibility issues is the sinking of the English destroyer Sheffield in the Anglo-Argentine armed conflict. The ship was attacked from a distance of about 30 km by two Super Etander aircraft, which fired two Exocet missiles. One of them hit his nose. The missile was detected visually six seconds before impact. The success of the strike was facilitated by the fact that during the attack the radar for detecting airborne targets of the meter range was turned off on the destroyer to eliminate interference with the Flitsatcom satellite communication system, through which negotiations were conducted with London.
The importance of the issues of ensuring the electromagnetic compatibility of radio electronic equipment is also shown by the experience of combat training, when unintentional interference is one of the reasons affecting the effectiveness of the integrated use of electronic means. Therefore, the provision of conditions for the effective functioning of the RES of ships and formations has now become an integral part of the arrangements for organizing their combat use. Electromagnetic compatibility is determined both by the characteristics of the RES themselves and by the creation of the appropriate modes of their operation. The issues of its provision should be addressed throughout the entire life cycle of the RES - at the stages of design, preparation and combat use.
In the navies of the capitalist states, much attention is paid to this problem. Work to ensure the EMC of RES is carried out within the framework of special programs (for example, in the USA - "TESER-80"). They provide for research, development and testing of existing and developed types of radio-electronic weapons and are aimed at introducing a systematic approach to the design and equipping of ships with radio-electronic means, taking into account their electromagnetic compatibility; development of a system of standards in the field of EMC; improving the technical characteristics of RES that affect EMC (reducing the side lobes of antenna devices, reducing the number of channels for unintentional interference, etc.); the introduction of effective protection devices against NRP, the principle of operation of which would take into account both the features of combat use and the design of the RES. Among the measures aimed at ensuring the EMC of RES include the correct choice of operating frequency ranges, improving the characteristics of radiation, reception and increasing noise protection against unintentional interference, as well as limiting parameters that affect electromagnetic compatibility.
A significant part of the measures to ensure EMC is carried out at the stages of preparation and conduct of hostilities. At the preparation stage, the expected radio-electronic and electromagnetic situation in the combat area is predicted (potentially incompatible radio-electronic equipment is identified based on the RES forms, operating experience and combat training, and the calculation of the NRP levels is made, dangerous interference situations are determined); frequency assignments are made to groups or individual RES, prohibited frequencies for operation are clarified (mainly for REP facilities); priority is established in the use of RES; the sectors of space in which they must work are assigned; temporal and spatial restrictions on the operation of RES are introduced; requirements are being developed to ensure EMC when building ship orders; control measures, their frequency, etc. are determined.
When conducting combat operations, it is advisable to use RES in accordance with previously developed options. During this period, only their adjustment can be carried out due to changes in the tactical and electronic situation. When ships operate as part of a formation, ensuring the electromagnetic compatibility of radio electronic devices is a particularly difficult task. If on one ship the types and parameters of unintentional interference are known and can be taken into account in all applications, then for the connection of ships their determination may not be accurate enough due to changes in the composition and location of the RES during combat operations.
The complex nature of the combat use of RES formations (associations) makes it necessary to consider them as a single system, which differs in: hierarchical structure of construction; the presence of a large number of interconnected and interacting elements; heterogeneity of intensive information flows; multicriteria; interaction with the external environment.
The hierarchical nature of the structure of this system (Fig. 1) predetermines the presence of two types of relations between its control and executive elements - subordination and interaction. The former are characterized, as a rule, only by information links that ensure the exchange of command information. And status information. The second - by the fact that, along with exchange-information, undesirable connections are established between subsystems (elements), one of the types of which is communication through an electromagnetic field. She something And predetermines the possibility of occurrence of electromagnetic incompatibility of RES. Therefore, when RES subsystems solve specific problems, conflict situations may arise (work in a common frequency band, simultaneous operation of several RES subsystems, etc.).
Rice. 1. Structure of the RES system
Since the subsystems solve their tasks autonomously, the general task of providing EMC requires their coordination, i.e., coordination in order to increase the overall total effect of the system functioning. At the same time, information about the state and parameters of individual RES, the conditions for their operation in the system may not be complete enough or change. As a result, the coordinator faces the problem of making a decision under conditions of uncertainty. The task of each local decision element is also considered as a decision-making problem under conditions of uncertainty, since it takes place in relation to the actions of local decision elements of other subsystems. And the success of system coordination depends on the choice of estimated parameter ranges.
The interaction between the coordinator and the decisive elements of the lower level in the theory of coordination is based on two principles.
First. Interaction prediction. The coordinator predicts the necessary frequency detuning, distances between incompatible RES, at which a given level of unintentional interference is provided. If at the same time it turns out that the order of application of the RES in the subsystem adopted by the local decision elements ensures the specified quality of the RES operation, then the coordination task is completed.
Second. Coordination of interaction. Each local decisive element has the right to make decisions independently. The principle involves the coordination of local quality functions so that a solution can be found with the independent operation of subsystems. The role of the coordinator is reduced to the coordination of the quality function of the system and the local quality functions of the subsystem. During coordination, the EMC conditions in the system are predicted for all variants of the tactical situation and at each stage of solving a combat mission. If the coordination of spatio-temporal and frequency modes of operation of all these electronic means fails to ensure the conditions for their electromagnetic compatibility, then the tactical formation of ships and the organization of the combat use of their subsystems change. An indicator of the quality of coordination is the effectiveness of these systems in solving a combat mission.
Coordination of EMC issues of RES of ships connection has its own characteristics. One of them is that they are included as a subsystem in a system of a higher order, such as associations. Therefore, their tasks are completely determined by the goals of the higher order system, and ensuring compatibility is carried out not only in the interests of the effective functioning of the means of connection, but also of the entire system as a whole.
Another feature is that the coordination does not seek to reach an optimum, but is aimed only at improving the performance of the system used. The tasks of subsystems are also formed in order to obtain a satisfactory, but not necessarily optimal solution. A practically strict optimum for many reasons turns out to be unrealizable (an ideal system), since often there is not enough information about the factors that affect the result of the chosen decisions, there are time limits, and the possibilities of RES subsystems are not unlimited.
Ensuring electromagnetic compatibility presupposes the availability of a priori information about the parameters of RES emissions, the tactical construction of the connection, the organization of their use, etc. Based on this information, using interaction models, an analysis of the interference electromagnetic environment is carried out, the most dangerous sources of unintentional interference are determined, an assessment of their interfering effects is given, predicted the number and types of RES, the operation of which can be partially or completely suppressed.
The analysis and assessment of the interference (electromagnetic) environment is usually carried out at several levels: paired, when the effects of interference created by each of the two radio-electronic means are taken into account; group, when the actions of the entire RES group for each receiver are taken into account; systemic, when the influence of all RES included in this system on each group is considered.
The most developed are the issues of assessing the electromagnetic situation in a duel situation (pair assessment). However, the solution of the problems of ensuring the EMC of RES by analyzing it in duel situations is not always justified and does not reflect the full picture of interfering effects, since in most cases more complex relationships arise between RES. The same can be said about group evaluation. Therefore, when evaluating EMC, the entire group of incompatible electronic means should be considered as a single system.
Technical and organizational measures to ensure the EMC of the RES are quite fully described in the specialized literature. We only note that the normalization of their frequency-territorial spacing is a necessary but insufficient measure to ensure EMC, since it does not exclude unintentional interference due to: continuous change of operating modes and operating frequencies due to enemy interference; a change in the relative position of incompatible means due to a change in the situation; random nature and incompleteness of information about radiation in a wide frequency band.
The coordination process contains two important points - the establishment of a priority for the operation of RES and an assessment of the effectiveness of measures to ensure their electromagnetic compatibility. Electronic means of one or more subsystems can operate in serial, parallel and serial-parallel time modes. In the event that it is not possible to provide EMC by using technical protection measures and frequency-territorial separation of the RES, temporary regulation (ranking of their work) is carried out. It is carried out on the basis of estimates of the effectiveness of the contribution of a particular tool to the solution of each problem. The matrix of priorities calculated in this way allows at each stage of the system functioning to give a temporary regulation of the work of the means included in it.
Evaluation of the effectiveness of measures to ensure the EMC of the RES can be carried out in terms of their success and usefulness. Both probabilistic indicators (probability of detection, probability of tracking, etc.) and indicators of changes in the tactical parameters of individual means and the entire system (detection range reduction, reduced throughput, etc.) can serve as success indicators. . The utility indicators characterize the contribution of the RES of the ship (combination) to the efficiency of the functioning of a higher-level system (combination, formation) in solving combat missions. Ultimately, the coordination of EMC issues comes down to the distribution of the frequency and space-time resource of the RES system in such a way as to ensure the solution of combat missions with a given efficiency.
The most difficult problem is the organization of the interaction of the forces of the fleet with the branches of service of other branches of the Armed Forces on the conduct of electronic warfare. Of particular importance is the solution of this problem in order to prevent (disrupt) a possible aggression or repulse a surprise attack by the enemy. The suddenness of hostilities does not leave time for the preparation and development of all issues of interaction, including the combat use of electronic means and systems. Hence the requirements for the level of combat readiness of duty forces and means, the need for early, clear coordination of their work in place, time, frequency bands, sectors of responsibility, the number of allocated forces and means.
Fundamentally, the issues of ensuring the EMC of the RES, subject to agreement, do not change: the distribution of the frequency-time and spatial resources of the RES operation and the implementation of appropriate control. Apparently, it is advisable to include them in the section of electronic protection in the annex to the plans for combat interaction. In the document being developed, the following should be reflected in the form of tables and graphs: frequency distribution (basic, spare, prohibited); time schedule of the RES; sectors of work of RES; dependence of the level of unintentional interference on the distance separately for coastal and ship-based RES. All these questions need to be developed in advance and assessed for their effectiveness. When the composition of forces changes, appropriate adjustments must be made immediately.
It is important to note that EMC is not the only factor affecting the efficiency of RES. Therefore, when organizing their use, it is necessary to take into account the impact of EMC measures on other components of electronic protection (protection of radio electronic devices from interference created by the enemy, etc.).
The problems of ensuring the electromagnetic compatibility of radio-electronic means in their complex use cannot be solved by setting a rigid algorithm of actions for all cases. Each time, many different factors should be taken into account, promptly respond to all changes in the situation (operational-tactical, radio-electronic, electromagnetic), the nature of the use of forces and radio-electronic means, and evaluate the effectiveness of solving the task at hand with the selected options for their work.
It seems appropriate in the course of planning the combat use of formations to provide for the solution of the problem of ensuring the EMC of the RES within the framework of a special operation to disrupt the operation of the enemy control system and ensure reliable control of one's own forces.
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Electromagnetic compatibility of radio-electronic means (EMC RES)
The ability of a radio-electronic means (RES) to function in real operating conditions with the required quality when exposed to unintentional interference, without creating radio interference with other RES of a group of troops. The problem of EMC, first of all, with the features of the functioning of the RES, which, as a rule, includes three main elements - a radio transmitter, a radio receiver and an antenna-feeder device. In this case, the radio transmitter is designed to generate, modulate and amplify high-frequency currents, the radio receiver is to select, convert, amplify and detect electrical signals, and the antenna-feeder device is to radiate and select electromagnetic oscillations of the radio range, as well as convert them into electric currents .
Each of these elements of the RES in its own way affects the EMC. A radio transmitting device, which is a source of radio emissions, is characterized by the following parameters: frequency, spectrum width, power, type of modulation. In the structure of radiation of a radio transmitter, the following types of radiation are distinguished: basic, out-of-band and spurious.
Taking into account the selected types of radiation, the main parameters of radio transmitting devices that affect EMC are: the power of the main radiation, the width of the spectrum of the main radiation, the carrier frequency (the center frequency of the spectrum of the main radiation), the operating frequency range, the stability of the transmitter, frequencies (bandwidths) and levels out-of-band and spurious emissions, etc.
The contribution of the radio receiver to the EMC problem of the RES is determined by the presence of various reception channels, both signals and interference.
Allocate the main receiving channel (the minimum frequency band in which it is possible to ensure high-quality (reliable) reception of a message at the required speed) and non-main receiving channels, which in turn are divided into adjacent ones (frequency bands equal to the main channel and directly adjacent to its lower and upper borders) and side (frequency band outside the main reception channel, being in which the signal or interference passes to the output of the radio receiver). The presence of minor reception channels is determined not only by the parameters of the element base of the receiving path, but also by the principles of constructing a radio receiver.
Of the side reception channels, the most well-known is the so-called mirror channel. This receiving channel is a mandatory accessory for superheterodyne receivers. A distinctive feature of the mirror reception channel is the same sensitivity as the main reception channel.
The main parameters of a radio receiver that affect EMC are: sensitivity, operating frequency range, bandwidth, intermediate frequency value, selectivity, image attenuation, etc.
Considering the antenna-feeder device from the point of view of their influence on EMC, we note that it solves the problems of spatial, polarization and, to a certain extent, frequency selection of radio waves. In this case, spatial selection is carried out due to the directional properties of most types of antennas, which are characterized by the dependence of the level of emitted or received radiation on the direction. This dependence is called the radiation pattern. As a rule, the radiation pattern has the main and side lobes of radiation (reception).
The capabilities of antenna systems for polarization selection are determined by its type, for example, a whip antenna generates (receives) an electromagnetic oscillation with vertical polarization, a helical one with circular polarization.
The frequency selection of antennas is determined by the dependence of its parameters on the frequency of radiated or converted radio emissions. The parameters of antenna-feeder devices that affect EMC are: the width of the radiation pattern, the level of side lobes, the operating range, etc. It should be noted that many of these parameters make up the performance characteristics of the radio transmitting, radio receiving and antenna-feeder devices.
Thus, even one RES has a large number of parameters and characteristics that determine its EMC, and ensuring the normal joint operation of dozens of different RES at one facility or hundreds and thousands of RES in a grouping of troops is a serious task.
Electromagnetic compatibility of radio electronic equipment
The direction of radio electronics, designed to ensure the simultaneous and joint operation of various radio, electronic and electrical equipment, is called the electromagnetic compatibility of radio electronic equipment (EMC RES).
Causes causing an exacerbation of the EMC problem:
the total number of simultaneously operating RTUs increases, especially those installed on mobile objects;
the power of radio transmitters is increasing, reaching tens of megawatts for some types of radio equipment;
the frequency bands used by many modern radio facilities are expanding;
electronic means of automatic control, monitoring, and diagnostics based on analog and digital technology are being introduced more widely;
the equipment of mobile objects with radio electronics increases, with an increase in the density of the equipment layout;
the conditions for the operation of RES of aircraft are deteriorating, as they are in the line of sight of an increasing number of ground-based RES located over a large area.
EMC Solution Trends:
improvement of individual schemes and design solutions;
radio frequency distribution planning.
systemic character;
accounting for EMC at all stages of the life cycle: development - manufacture - operation.
The engineer must know:
causes of interference;
properties and characteristics of various elements of the RES that affect the processes of creating interference and exposure to them;
basic methods and tools for analyzing EMC indicators;
principles and main directions of providing EMC;
standards and regulations in the field of EMC.
Types of radio interference
Electromagnetic interference is an undesirable effect of electromagnetic energy that degrades (or may degrade) the quality of the functioning of the means.
Interference is different:
by origin,
by structure,
by spectral and temporal characteristics.
natural interference are caused by electromagnetic processes that exist in nature and are not directly related to human activity:
Reasons for the appearance:
electrical processes occurring in the atmosphere;
thermal radio emissions of the earth's surface, troposphere and ionosphere;
noise radio emissions from extraterrestrial (cosmic) sources.
Properties: A continuous or pulsed wideband process that is considered close to normal white noise within the receiver bandwidth.
Artificial interference - caused by human activity and due to various electromagnetic processes in technology.
deliberate - they are specially created for the purpose of disrupting the normal functioning of specific RES (creation and counteraction).
Unintentional interference (NEMI) - are created by sources of artificial origin, which are not intended to disrupt the functioning of the RES.
Occurs at work:
Radio engineering,
electronic,
electrical equipment.
share
caused by radiation from the reactor;
industrial interference.
Internal noise
noise in conductive materials
noise in vacuum tubes
noise from solid state devices
Antenna noise temperature
External interference and internal noise are energetically equivalent, therefore they are evaluated by one parameter - the noise temperature of the antenna - allows you to determine the power supplied to the matched receiver by the receiving antenna of noise interference per frequency band:
P sha = k T a B
P sha (W) - the power of the receiving antenna noise interference
k \u003d 1.38 10 -23 (J / K) - Boltzmann's constant;
T a (K) - antenna noise temperature
B (Hz) - frequency band
Figure 1. 1 - internal noise; 2 – city noises; 3 - noise in the countryside; 4 - cosmic noises; 5 - atmospheric noise.
Ways of exposure to unintentional interference.
Interference source(IP) - radio, electrical, electronic means that create electromagnetic interference during operation.
Interference receptors(RP) - devices subjected to interference.
Interference influence: - direct; - indirect
Immediate impact
the source of interference is the transmitter, the receptor is the receiver. The radiation and reception of unwanted vibrations by the antennas of devices prevails.
The electromagnetic interference field is created by currents flowing in various elements of the IP structures. Interference exists in the surrounding space in the form of freely propagating or guided electromagnetic waves. Interference acts on the receptor due to the appearance of induced EMF in the elements of the electric circuits of the RP.
Elimination of NEMF - significant attenuation along the propagation path.
Case 1: freely propagating waves
The level of interference depends on:
from the power of IP;
distance to receptor (r)
interference wavelength ();
environment parameters;
location
near zone r
intermediate zone /2
far zone r > r 2 max / (r max is the maximum size of the antenna aperture).
Far: energy is transmitted by electromagnetic waves freely propagating in the surrounding space.
Properties:
transverse structure of electromagnetic fields;
field components change with distance proportionally to 1/r
constancy of the angular distribution of the intensity of electromagnetic fields with a change in distance;
Emission and reception of interference can be carried out both by antennas and housings, cables, mounting elements, power supply and control circuits.
Intermediate: electromagnetic fields emitted by individual sections of the current regions of the IP have a transverse structure and are propagating electromagnetic waves. The resulting field at the receiving point is a superposition of these waves. The phase relations are determined both by the angular coordinates and by the distance between the IP and the RP.
Near: The energy density of electric and magnetic fields are not equal. The values of the strength components change with distance in proportion to 1/r 2 and 1/r 3 .
They exist in cables, waveguides - transmission lines.
Characteristic: spread without significant weakening.
Galvanic connection- in the presence of common elements in the electrical circuits of the IP and RP.
Due to:
conduction currents;
due to imperfection of insulating materials;
the presence of common areas in the ground circuits.
Indirect influence– there is no direct transmission of electromagnetic energy.
Impact due to:
changes in environment settings;
changing the parameters of device elements;
changing the operating modes of the device.
For example: changing the parameters of the ionosphere; changing the power consumption mode.
In general, the task of determining the degree of achievement of EMC in a particular situation is reduced to solving two particular problems: external and internal (in relation to this RES) .
External task lies in assessment of the electromagnetic environment (EMS) at the location of the receiver-receptor, defined as a set of parameters of useful and interfering signals at the receptor input. At the same time, a EMO statistical model, which, along with constant parameters (detuning of the carrier frequencies of the PS and MS, their average power values, etc.) includes all the probabilistic parameters of useful and interfering radio signals, taking into account the statistical nature of their formation and propagation: the randomness of the parameters of the modulating signals for a given type of modulation, fast and slow fading of useful and interfering radio signals, possible nonlinear effects in the receiver with increased levels of radio signals at the receiver input). Internal task is to quantify the degree of impact of unintentional interference on the quality of the functioning of the RES . The solution of the internal problem is usually carried out using the methods of statistical radio engineering and the statistical theory of optimal signal reception, developed in relation to cases of exposure to unintentional interference, taking into account the need to ensure the EMC of the RES.
The decision on whether the EMC of the considered set of RES is achieved should be made based on the admissibility or inadmissibility calculated percentages of time of unacceptable decrease in the quality of functioning of the radio receivers of all RES in this EMO due to the influence of interfering signals. This implies a three-stage scheme for solving the problem of EMC assessment:
Stage 1. The problem is being solved EMO scores . As noted above, its initial data are geographical and energy characteristics and parameters of sources of useful and interfering signals. The result of solving this problem is the quantitative deterministic and probabilistic characteristics of useful and interfering signals affecting the receiving device of each of the RES. In this case, the set of interfering signals that are potentially dangerous in relation to EMC violations and require quantitative analysis is called interference environment.
Stage 2. The problem is being solved evaluation of the deterioration in the reception quality of the useful signal due to unintentional interference. The initial data for its solution are the results of solving the problem of the first stage. The result of solving the problem of the second stage characterizes the degree.
Stage 3. Based on the results of solving the problem of the second stage, evaluation of EMC RES , based on exceeding or not exceeding the allowable values calculated according to the selected EMC criterion by the percentage of time of unacceptable deterioration in quality operation of radio receivers all RES in this EMO due to the influence of interfering signals.
EMC evaluation of RES can be done in various ways:
1/ settlement;
2/ experimental - based on measurements of a number of parameters of interacting RES;
3/ mixed (combination of calculation and experimental methods).
EMC calculation methods are used in solving the following tasks:
Prediction of the electromagnetic environment;
Long-term planning and efficient use of the radio frequency spectrum;
Preparation of materials for conclusions (decisions) on the right to use certain frequency bands;
Determination of the degree of provision of EMC RES;
Assessment of the degree of influence of unintentional interference on the quality of the functioning of the RES;
Evaluation of the effectiveness of measures to ensure the EMC of the RES;
Development of norms for frequency-territorial spacing between RES.
Given the importance of solving EMC problems, in many countries, including Russia, there is a whole system of regulatory documents (State Standards, Norms for transmitter radiation parameters, etc.) that regulate the main characteristics and parameters of RES that affect their EMC . The most important normative documents of this kind include the following:
GOST 30372-95. Electromagnetic compatibility of technical means. Terms and Definitions;
GOST 23882-710. Compatibility of radio electronic means is electromagnetic. Nomenclature of parameters and classification of technical characteristics;
GOST R50842-95. Radio transmitting devices for national economic use. Requirements for spurious radio emissions. Methods of measurement and control;
GOST R 51319-910. Compatibility of technical means is electromagnetic. Instruments for measuring industrial radio interference. Technical requirements and test methods.
GOST R 51320-910. Compatibility of technical means is electromagnetic. Industrial radio interference. Test methods for technical means - sources of industrial interference;
Norms 19-02. Standards for the bandwidth of radio frequencies and out-of-band emissions of radio transmitters for civil use.
1.5 General EMC practices
Ensuring EMC in practice is achieved by the implementation of a set of organizational and technical measures that are mandatory for users of the radio spectrum, established and controlled by the relevant state bodies:
a) centralized distribution and allocation of frequency bands to various radiocommunication services;
b) science-based management of the radio spectrum;
c) strict control over the fulfillment of EMC regulatory indicators (in particular, limiting the power of radio emissions in certain directions).
One of the most important technical ways to achieve EMC of RES is to provide frequency-territorial spacing (FTR) of these RES. FTD is a combination of frequency separation (FR - the difference between the operating frequencies of the MS and MS transmitters) and the minimum required territorial separation (TR) of each of the interfering signal transmitters relative to the receptor. The TR for each interfering transmitter depends, in particular, on the set of parameters Rm, and the so-called “situational plan” (Fig. 1.8).
In Fig. 1.8, the following designations are adopted: RRS - radio station of the main (useful) radio communication system (RSS), affected by MS from another RES; MPS - interfering CRS radio station, which is the source of MS for the considered RRS; Rc is the length of the MS propagation path; Rm is the length of the MS propagation path; f pd s is the frequency of the PS; DNA - antenna pattern; MS - moving radio signal; j m is the angle of arrival of the MS; f pd m - MS frequency;; a m is the MS exit angle.
In addition to general organizational and technical measures, various
special technical means that reduce the effect of MS on the quality of PS reception by reducing the level of MS at the receptor input or weakening the effect of MS on the quality of reception through the use of interference compensators. These tools are discussed in Chapter 10.
Fig. 1.8 Situational plan of the interference situation when exposed to one interfering signal
The general methodology for analyzing the EMC of RES, which includes a general algorithm for analyzing EMC, preparation and primary analysis of initial data for an arbitrary complex case of EMT, an algorithm for checking the implementation of EMC for each interaction option in this EMT, examples of EMC calculations for various options and a list of references containing a large number of necessary for calculations of ITU-R Recommendations, are given in .