RU2299832C1 - Man-overboard detection system - Google Patents

Abstract

FIELD: lifesaving equipment; man-overboard detection systems.

SUBSTANCE: proposed system includes life jacket and receiver mounted on monitoring station. Life jacket has two light sources, two transmitters with transmitting antennae and power source. Each transmitter is provided with master oscillator 62, n-tap delay line 63.i (i=1, 2, ....,n), phase inverters 64.j (j= 1, 2,..., m), adder 65 and power amplifier 66. Receiver has three receiving antennae. Three high-frequency amplifiers, three mixers, two heterodynes, five multipliers, four narrow-band filters, three intermediate frequency amplifiers, four threshold units, six switches, two phase meters, recording unit and low-pass filter.

EFFECT: extended functional capabilities; enhanced reliability of detection of man overboard.

8 dwg

Description

The proposed system relates to rescue equipment and can be used to detect a person in distress on the water, and determine his location.

Rescue systems and devices are known (autoswed. USSR No. 385819, 431063, 637298, 765113, 988655, 1348256, 1505840, 1506841, 1588636, 1615054, 1643325, 1664653; RF patents No. 20000005, 2038259, 2043259, 2051838, 2151899, 21835999 , 2,240,950; U.S. Patent Nos. 3,361,501, 4,898,511; UK Patent No. 114,451; Danish Patent No. 103,118 and others).

Of the known systems and devices closest to the proposed is the "System for the detection of a person in distress on the water" (RF patent No. 2240950, B63C 9/20, 2003), which is selected as a prototype.

This system provides increased noise immunity of the receiver, eliminates the ambiguity of measuring the carrier frequency and improves the reliability of detection of a person in distress on the water. This is achieved by suppressing false signals (interference) received via additional channels. Moreover, to suppress these signals, correlation processing of received distress signals is used. Due to the correlation processing of received distress signals, the ambiguity of phase measurements is also eliminated.

In this case, the distress signal (SOS) is emitted periodically with a certain period T _{p of} duration T _s at a certain frequency ωс, which is allocated specifically for transmitting a distress signal and is not involved in transmitting other information. This signal is a simple harmonic signal and does not provide the ability to transmit basic information about a person in distress on the water.

An object of the invention is to expand the functionality of the system and increase the reliability of detection of a person in distress on water by using a complex signal with phase shift keying, providing the transfer of basic information about a person in distress on water.

The problem is solved in that the system for detecting a person in distress on the water, including a life jacket, dressed on a person and containing two light sources, one of which is located in the chest area of the life jacket, and the other in the back area, a current source, two circuit breakers, two communicating sealed containers, each of which is separated from the environment by a membrane, while one of the sealed containers is located in the chest area of the life jacket, and the other in the back of its area, the membranes of each capacity are connected to the circuit breaker of the corresponding light source by means of a lever, and both light sources are connected in parallel through the switches to the current source, and two miniature transmitters with transmitting antennas, one of which is located in the chest area of the life jacket, and the other - in its back area, a receiver installed at the control point and containing in series the first receiving antenna, the first high-frequency amplifier, the first mixer, the second the first input of which is connected to the first output of the first local oscillator, the first intermediate frequency amplifier, the second multiplier, the second narrow-band filter, the first key, the third key, the second input of which is connected through the third threshold block to the second output of the first block of correlators, the first phase meter and the registration block, in series included a second receiving antenna, a second high-frequency amplifier, a second mixer, the second input of which is connected to the first output of the second local oscillator, and a second intermediate-frequency amplifier, the output to which is connected to the second input of the second multiplier, a third receiving antenna, a third high-frequency amplifier, a third mixer, a second input of which is connected to the first output of the second local oscillator, a third intermediate frequency amplifier, a third multiplier, the second input of which is connected to the output of the first intermediate-frequency amplifier, connected in series , the third narrow-band filter, the second key, the fourth key, the second input of which is connected through the fourth threshold block to the second output of the second block of correlators, and the second the second phase meter, the output of which is connected to the second input of the recording unit, the first multiplier connected in series to the second output of the first local oscillator, the second input of which is connected to the second output of the second local oscillator, and the first narrow-band filter, the output of which is connected to the second input of the first and second phase meters, connected in series to the output of the first intermediate frequency amplifier, the first block of correlators, the second input of which is connected to the output of the second intermediate frequency amplifier, and the first threshold block, in the path of which is connected to the second input of the first key, connected in series to the output of the third intermediate frequency amplifier, the second block of correlators, the second input of which is connected to the output of the first intermediate frequency amplifier, the second threshold block, the output of which is connected to the second input of the second key, while the frequency of the first ωg ₁ and second ωg ₂ local oscillators are spaced by twice the intermediate frequency

ωg ₂ -ωg ₁ = 2ωpr

and are chosen symmetrical with respect to the carrier frequency ωc of the received distress signal

ωс-ωг ₁ = ωг ₂ -ωс = ωпр,

equipped with a fifth and sixth keys, a fourth and fifth multipliers, a fourth narrow-band filter and a low-pass filter, and a fifth key is connected in series to the output of the first intermediate-frequency amplifier, the second input of which is connected to the output of the third threshold unit, the sixth key, the second input of which is connected to the output the first threshold unit, the fourth multiplier, the second input of which is connected to the output of the low-pass filter, the fourth narrow-band filter, the fifth multiplier, the second input of which is connected to by the output of the sixth key, and a low-pass filter, the output of which is connected to the third input of the registration unit, each transmitter is made in the form of series-connected master oscillator, n-tap delay line, in some n-taps of which phase inverters, adder, (m + 1) are included the nth input of which is connected to the output of the master oscillator, and the power amplifier whose output is connected to the transmitting antenna, the delay time τ3 between adjacent taps of the n-tap delay line is chosen equal to the duration of the radio pulse τe.

Figure 1 schematically depicts a life jacket, dressed on a man, figure 2 is the same section.

The structural diagram of the receiver installed at the control point is presented in figure 3. A frequency diagram illustrating the formation of additional reception channels is shown in FIG. 4. The relative position of the receiving antennas is shown in Fig.5. The geometric arrangement of the aircraft (LA) and a person in distress on the water is shown in Fig.6. The structural diagram of the transmitter 19 (20) is presented in Fig.7. Timing diagrams explaining the principle of the system are shown in Fig. 8.

The system contains a life jacket with light sources 1 and 2, transmitters 19 and 20 with transmitting antennas 21 and 22, respectively, and a receiver installed at the control point.

The life jacket also contains an energy source 3 (FIG. 2), cables 4 and 5 for supplying energy to light sources 1 and 2 and transmitters 19 and 20, cartridges 6 and 7, membranes 8 and 9, and levers 10 and associated with them 11 with contacts 12 and 13, as well as a sealed pneumatic line 14 connecting the sealed air cavities 15 and 16. The entry points of cables 4 and 5 from the energy source 3 in the cavities 15 and 16 are sealed with o-rings 17 and 18. The light source 1 and the transmitter 19, light source 2 and transmitter 20 are connected in parallel to energy source 3.

Each transmitter 19 (20) is made in the form of series-connected master oscillator 62, n-tap lines 63.i (i = 1, 2, ..., n), the delay time τz _i between the nearest adjacent taps is equal to the duration τe of the radio pulse (τз _i = τэ). In some taps of the delay line 63.i, phase inverters 64.j are included (j = 1, 2, ..., m), which provide 180 ° phase rotation at their outputs in accordance with the identification code M (t) (Fig. 8, b) a person in distress on the water. The outputs of the m-phase inverters and the output of the master oscillator 62 are connected to an adder 65, the output of which is connected through a power amplifier 66 to a transmitting antenna 21 (22).

The receiver installed at the control point contains in series a first receiving antenna 23, a first high-frequency amplifier 26, a first mixer 31, a second input of which is connected to the first output of the first local oscillator 29, a first intermediate-frequency amplifier 34, a second multiplier 39, and a second narrow-band filter 41 , the first key 47, the third key 51, the second input of which through the third threshold block 49 is connected to the second output of the correlator block 43, the first phase meter 53 and the registration block 55, sequentially connected to the second receiving antenna nnu 24, the second high-frequency amplifier 27, the second mixer 32, the second input of which is connected to the first output of the second local oscillator 30, and the second intermediate-frequency amplifier 35, the output of which is connected to the second input of the multiplier 39, the third receiving antenna 25 connected in series, the third amplifier 28 high frequency, the third mixer 33, the second input of which is connected to the first output of the second local oscillator 30, the third intermediate frequency amplifier 36, the third multiplier 40, the second input of which is connected to the output of the amplifier 34 in between frequency, the third narrow-band filter 42, the second key 48, the fourth key 52, the second input of which through the fourth threshold block 50 is connected to the second output of the second block 44 of the correlators, and the second phase meter 54, the output of which is connected to the second input of the registration block 55, connected in series to the second output of the first local oscillator 29, the first multiplier 37, the second input of which is connected to the second output of the second local oscillator 30, and the first narrow-band filter 38, the output of which is connected to the second input of the first 53 and second 54 phase meters, to the output of the first about the intermediate frequency amplifier 34, the first correlator block 43 is connected in series, the second input of which is connected to the output of the second intermediate frequency amplifier 35, and the first threshold block 45, whose output is connected to the second input of the first key 47, the second second frequency amplifier 36 is connected in series a correlator block 44, the second input of which is connected to the output of the first intermediate frequency amplifier 34, and a second threshold block 46, the output of which is connected to the second input of the second key 48, the fifth key 56, the second input of which is connected to the output of the third threshold block 49, the sixth key 57, the second input of which is connected to the output of the first threshold block 45, the fourth multiplier 58, the second input of which is connected to the output of the filter 61 low pass filters, a fourth narrow-band filter 60, a fifth multiplier 59, the second input of which is connected to the output of the key 57, and a low-pass filter 61, the output of which is connected to the third input of the registration unit 55.

The system operates as follows.

In the position shown in FIG. 1, the ambient pressure P ₂ on the membrane 9 is greater than the atmospheric pressure P ₁ on the membrane. The membrane 9 is in a preloaded position, the membrane 8 is in a depressed state. Therefore, the lever 11 depresses the contact 13 from the light source 2 and the transmitter 20, and the lever 10 pushes the contact 12 to the light source 1 and the transmitter 19. The light source 1 is on, the light source 2 is off, the transmitter 20 is not working, the transmitter 19 is turned on.

In this case, the master oscillator 62 generates a radio pulse (Fig. 8, a)

Is (t) = Uc Cos (ωct + φс), 0≤t≤τэ,

where Uc, ωс, φс, τэ - amplitude, carrier frequency, initial phase and duration of the radio pulse, which is fed to the input of the multi-tap line 63.i (I = 1, 2, ..., n) and to (m + 1) - the input of the adder 65 in the multi-tap delay line 63.i, the delay time τз _i between the nearest neighboring taps is equal to the duration of the radio pulse τэ (τз _i = τэ, i = 1, 2, ..., n). In some taps of the delay line, phase inverters 64.j (j = 1, 2, ..., m) are turned on, providing at their outputs a phase rotation of 180 ° in accordance with the identification code M (t) (Fig. 8, b) of a person, in distress on the water. The output of the adder 65 produces a complex signal with phase shift keying (QPSK) in the form of the algebraic sum of radio pulses from all taps of the delay line 63.1 and from the output of the master oscillator 62 (Fig. 8, e)

Is ′ (t) = Uc · Cos [ωct + φk (t) + φс], 0≤t≤Тс,

where φk (t) = {0, π} is the manipulated component of the phase that displays the law of phase manipulation in accordance with the modulating code M (t) (Fig. 8, b), and φk (t) = const for kτe <t <( k + 1) τe and can change abruptly at t = kτe, i.e. at the boundaries between elementary premises (radio pulses) (k = 1, 2, ..., n);

τe, n is the duration and number of elementary packages (radio pulses) of which the signal is composed of a duration of Tc (Tc = τe · n).

Each person in distress on the water has his own individual modulating code M (t), which contains, for example, last name, first name and patronymic, belonging to the country, company, type of ship, etc.

This QPSK signal after amplification in the power amplifier 66 is transmitted by the transmitting antenna 21 to the air (Fig. 7).

If a person makes a 180 ° rotation about the horizontal axis, then the light source 2 and the transmitter 20 with the transmitting antenna 22 are at the top.

The pressure of the medium on the membrane 8 becomes greater than on the membrane 9, the membrane 8 is pressed, the lever 10 opens the contact 12 with the light source 1 and the transmitter 19 with the transmitting antenna 21, the circuit opens, the light source 1 goes out, the transmitter 19 turns off. At the same time, air from the cavity 15 flows through the line 14 into the cavity 16, the membrane 9 is squeezed out, the lever 11 closes the contact 13 with the light source 2 and the transmitter 20 with the transmitting antenna 22. The light source 2 lights up, and the transmitter 20 emits a complex FMN distress signal.

At night and in good weather, the light source can be detected visually at a considerable distance. However, in daylight and in bad weather, the light source is difficult to detect.

Radio emission is weatherproof and provides distress signal transmission over long distances. In this case, the FMN distress signal (SOS) is emitted periodically with a certain period Tn and duration Tc at a certain frequency ωc, which is allocated specifically for transmitting a distress signal and is not involved in transmitting other information.

The direction finding receiver is located at a control point that can be placed on land, on ships of various purposes, including search and rescue ships, as well as on aircraft (helicopters, airplanes and spacecraft).

Receiving antennas 23, 24 and 25, raised above the surface of the water, for example, using an aircraft and located in the form of a geometric right angle (figure 5), receive a distress signal:

where ± Δω is the instability of the carrier frequency of the distress signal due to the Doppler effect and other destabilizing factors;

φ1-φ3 are the initial phases of the distress signal received by antennas 23-25.

These signals from the output of the receiving antennas 23-25 through the high-frequency amplifiers 26-28 are fed to the first inputs of the mixers 31-33, the second inputs of which are the voltage of the local oscillators 29 and 30;

the frequencies of which are spaced by a double value of the intermediate frequency

ωg2-ωg1 = 2ωpr

and are chosen symmetric with respect to the carrier frequency ωс

ωс-ωг1 = ωг2-ωc = ωпр.

This circumstance leads to a doubling of the number of additional receiving channels, but creates favorable conditions for their suppression by correlation processing.

At the outputs of the mixers 31-33, voltages of combination frequencies are generated. Amplifiers 34-36 are allocated voltage intermediate (differential) frequency:

wherein υpr1 = _^1/2 K1 · υc · υg1

υpr2 = _^1/2 K1 · υc · υg2

K1 is the transfer coefficient of the mixers;

ωpr = ωc-ωg1 = ωg-ωc - intermediate frequency;

φpr1 = φ1-φg1; φpr2 = φ2-φ2; φпр3 = φг2-φ3.

The voltages U1 (t) and U2 (t) from the second outputs of the local oscillators 29 and 30 are fed to two inputs of the multiplier 37, at the output of which a voltage is generated

Uг (t) = υг · Cos [(ωг2-ωг1) t + φг = υг · Cos (2ωпрt + φг)],

wherein υg = _^1/2 · K2 · υg1 υg2;

K2 - transmission coefficient of the multiplier;

φg = φg2-φg1,

which is allocated by the narrow-band filter 38.

The voltages Upr1 (t) and Upr2 (t), Upr1 (t) and Upr3 (t) from the outputs of the amplifiers 34, 35 and 36 are fed to the inputs of the multipliers 39 and 40, at the outputs of which the voltages are generated:

wherein υ4 = _^1/2 · K2 · υpr1 υpr2;

υ5 = _^1/2 · K2 · υpr1 υpr3;

d1, d2 - measuring bases,

X is the wavelength

α, β are the angular coordinates (azimuth and elevation angle) of the distress signal source, which are distinguished by narrow-band filters 41 and 42, respectively.

Voltages Upr1 (t) and Upr2 (t), Upr1 (t) and Upr3 (t) from the outputs of amplifiers 34-36 of intermediate frequency simultaneously arrive at two inputs of blocks 43 and 44 of the correlators, the outputs of which generate voltages proportional to the correlation functions R1 ( τ) and R2 (τ). The indicated voltages are applied to the inputs of the threshold blocks 45 and 46, where they are compared with the threshold voltage υпор1.

Since the channel voltages Upr1 (t) and Upr2 (t), Upr1 (t) and Upr3 (t) are formed by the same FMN distress signal received at the carrier frequency ωc, there is a strong correlation between them. The correlation function of QPSK signals has a remarkable property - it has a high level of the main lobe and a relatively low level of side lobes. The output voltages reach their maximum value and exceed the threshold level υпор1 in the threshold blocks 45 and 46.

When the threshold voltage υпор1 is exceeded, constant voltages are generated in the threshold blocks 45 and 46, which are supplied to the control inputs of the switches 47, 57 and 48, opening them. In the initial state, keys 47, 48, 51, 52, 56, and 57 are always closed.

At the second outputs of the blocks 43 and 44 of the correlators, voltages are generated that are proportional to the correlation functions R3 (τ) and R4 (τ). The indicated stresses reach their maximum value only with true values of the angular coordinates α and β. And only at these values in the threshold blocks 49 and 50 are constant voltages formed, which are supplied to the control inputs of the keys 51, 52 and 56, opening them.

In this case, the voltages U4 (t) and U5 (t) from the outputs of the narrow-band filters 41 and 42 through the public keys 47, 51 and 48, 52 are supplied to the first inputs of the phase meters 53 and 54, the second inputs of which are supplied with the voltage Uг (t) from the output narrow-band filter 38. Phasometers 53 and 54 measure the phase shifts Δφ1 and Δφ2, which are recorded by the registration unit 55.

Knowing the flight altitude h of the aircraft and measuring the angular coordinates αi and βi, it is possible to accurately and unambiguously determine the coordinates of the radiation source of the FMN distress signal (a person in distress on water) (Fig.6).

At the same time, the voltage Upr1 (t) (Fig. 8, e) from the output of the intermediate frequency amplifier 34 through the public keys 56 and 57 is supplied to the first inputs of the multipliers 58 and 59.

The second input of the multiplier 59 from the output of the narrow-band filter 60 receives the reference voltage (Fig.8, g)

Uo (t) = υo · Cos [(ωpr ± Δω) t + φpr1], 0≤t≤Ts

The output of the multiplier 59 produces a total voltage

UΣ (t) = υΣ · Cosφk (t) + υΣ · Cos [2 (ωpr ± Δω) t + φk (t) + 2φpr1],

wherein υΣ = _^1/2 υpr1 K2 · · υo.

The low-pass filter 61 emits a low-frequency voltage (Fig. 8, h)

Un (t) = υΣ Cosφk (t),

proportional to the modulating code M (t) (Fig. 8, b), which is registered by the registration unit 55.

At the same time, the voltage Un (t) from the output of the low-pass filter 61 is supplied to the second input of the multiplier 58. The harmonic voltage Uo (t) = υ1 · Cos [(ωpr ± Δω) t + φpr1] + υ1 · Cos [(ωpr ± Δω) t + 2φk (t) + φпр1] = 2υ1 · Cos [(ωпр ± Δω) t + φпр1] = υo · Cos [(ωп ± Δω) t + φп1],

where υo = 2υ1,

which is allocated by the narrow-band filter 60, is used as a reference voltage and is supplied to the second input of the multiplier 59.

The operation of the receiver described above corresponds to the case of receiving a useful FMN distress signal on the main channel at a frequency ωc.

If a false signal (interference) is received through the first mirror channel at a frequency ωz1 or through a second mirror channel at a frequency ωz2, then there are no voltage correlators at the first outputs of blocks 43 and 44. Keys 47, 48 and 57 do not open and the indicated false signals (interference) are suppressed.

For a similar reason, false signals (interference) received on the first combination channel at the frequency ωk1, or on the second combination channel at the frequency ωk2, or through any other additional channel, are also suppressed.

If false signals (interference) are simultaneously received through the first and second mirror channels at frequencies ωz1 and ωz2, then voltages are generated at the first outputs of blocks 43 and 44 of the correlators. However, the keys 47, 48 and 57 in this case do not open. This is due to the fact that channel voltages are generated by different false signals (interference) received at different frequencies ωz1 and ωz2. Therefore, there is a weak correlation between channel voltages. The output voltages of the correlator blocks 43 and 44 do not reach the maximum value and do not exceed the threshold voltage υпор1 in the threshold blocks 45 and 46. The keys 47, 48 and 57 do not open and the indicated false signals (interference) are suppressed.

For a similar reason, all other false signals (interference) simultaneously received on two or more other additional channels are suppressed.

The receiver is invariant to the instability of the carrier frequency and the type of modulation of the received signals, since the direction finding of the radiation source of the FMN distress signal is carried out at a stable frequency equal to the frequency difference ωg2-ωg1 = 2ωpr of local oscillators 29 and 30.

To suppress false signals (interference) received via additional channels, correlation processing of received distress signals is used. Due to the correlation processing of received distress signals, the ambiguity of phase measurements is also eliminated.

Thus, the proposed system in comparison with the prototype provides an increase in the reliability of detection of a person in distress on the water. This is achieved through the individual identification of each person in distress on the water, and the use of complex PSK signals.

These signals open up new possibilities in the technology of transmitting alarm messages. They allow you to apply a new type of selection - structural selection. This means that there is a new opportunity to separate signals operating in the same frequency band and at the same time intervals. Fundamentally, you can abandon the traditional method of dividing the operating frequencies of the used range between the working transmitters, which are equipped with life jackets, and their selection at the control point using frequency filters. It can be replaced by a new method based on the simultaneous operation of each transmitter in the entire frequency range with complex signals with phase manipulation with the selection by the receiver of the signal of the necessary transmitter through its structural selection.

Among other problems, the solution of which largely determines the further progress of radio communications, should include the problem of establishing a reliable connection between a person in distress on the water and a control point if there is a multipath nature of the propagation of radio waves. The presence of the multipath nature of the propagation of radio waves leads to a distortion of the received signals, which complicates the reception and reduces the reliability of the transmission of alarm messages.

Attempts to overcome the harmful effects of multipath have been made for a long time. These include diversity reception, signal selection by time and angle of arrival, corrective coding, and some other methods. However, all of them do not provide a fundamental solution to the problem.

Due to its good correlation properties, signals with phase shift keying can be “folded” into narrow pulses whose duration is inversely proportional to the used bandwidth. Choosing such a frequency band so that the duration of the “convoluted” pulse is less than the delay time, it is possible to separately receive pulses arriving at the receiving point in various ways, and by summing their energy, it is also possible to increase the noise immunity of complex QPSK signals. Thus, the indicated problem gets a fundamental solution.

From the point of view of detection, complex QPSK signals have high energy and structural secrecy.

The energy secrecy of these signals is due to their high compressibility in time and spectrum with optimal processing, which reduces the instantaneous radiated power. As a result of this, a complex QPSK signal at the receiving point may be masked by noise and interference. Moreover, the energy of a complex QPSK signal is by no means small; it is simply distributed over the time-frequency domain so that at each point of this region the signal power is less than the power of noise and interference.

The structural secrecy of complex QPSK signals is caused by a wide variety of their forms and significant ranges of parameter changes, which makes it difficult to optimally or at least quasi-optimally process complex QPSK signals of an a priori unknown structure in order to increase the sensitivity of the receiver.

The reference voltage necessary to extract the modulating code from the received PSK signal is generated directly from the received PSK signal of intermediate frequency. For this, a universal demodulator of QPSK signals is used, consisting of multipliers 58 and 59, a narrow-band filter 60, and a low-pass filter 61. The proposed demodulator is free from the phenomenon of “processing work” inherent in the known devices Pistolkors A. A., Siforev V. I., Travina G. A. and Kostas D.F.

Thus, the functionality of the system is expanded.

Claims (1)

A system for detecting a person in distress on the water, including a life jacket dressed on a person and containing two light sources, one of which is located in the chest area of the life jacket, and the other in its back area, a current source, two circuit breakers, two interconnected sealed containers, each of which is separated from the environment by a membrane, while one of the sealed containers is located in the chest area of the life jacket, and the other in its back area, the membrane of each container and connected to the circuit breaker of the corresponding light source by means of a lever, and both light sources are connected in parallel with the current source through the breakers, and two miniature transmitters with transmitting antennas, one of which is located in the chest area of the life jacket and the other in its back area and a receiver installed at the control point and containing in series the first receiving antenna, the first high-frequency amplifier, the first mixer, the second input of which is connected to the first the output of the first local oscillator, the first intermediate frequency amplifier, the second multiplier, the second narrow-band filter, the first key, the third key, the second input of which is connected through the third threshold block to the second output of the first block of correlators, the first phase meter and the registration block, the second receiving antenna, the second one connected in series, the second a high frequency amplifier, a second mixer, the second input of which is connected to the first output of the second local oscillator, and a second intermediate frequency amplifier, the output of which is connected to the second input to the third multiplier, the third receiving antenna, the third high-frequency amplifier, the third mixer, the second input of which is connected to the first output of the second local oscillator, the third intermediate frequency amplifier, the third multiplier, the second input of which is connected to the output of the first intermediate-frequency amplifier, the third narrow-band filter, the second key, the fourth key, the second input of which is connected through the fourth threshold block to the second output of the second block of correlators, and the second phase meter, the output of which is connected is connected to the second input of the registration unit, the first multiplier connected in series to the second output of the first local oscillator, the second input of which is connected to the second output of the second local oscillator, and the first narrow-band filter, the output of which is connected to the second input of the first and second phase meters, connected in series to the output of the first intermediate amplifier frequency, the first block of correlators, the second input of which is connected to the output of the second intermediate frequency amplifier, and the first threshold block, the output of which is connected to the second input the first key, sequentially connected to the output of the third intermediate frequency amplifier, the second block of correlators, the second input of which is connected to the output of the first intermediate frequency amplifier, and the second threshold block, the output of which is connected to the second input of the second key, the frequencies of the first ω1 and second ω2 local oscillators spaced twice the intermediate frequency ωg2-ωg1 = 2ωpr and are chosen symmetrical with respect to the carrier frequency ωc of the received distress signal ωс-ωг1 = ωг2-ωс = ωпр, characterized in that it is equipped with a fifth and sixth keys, a fourth and fifth multipliers, a fourth narrow-band filter and a low-pass filter, and a fifth key is connected in series to the output of the first intermediate frequency amplifier, the second input of which is connected to the output of the third threshold block, the sixth key, the second the input of which is connected to the output of the first threshold block, the fourth multiplier, the second input of which is connected to the output of the low-pass filter, the fourth narrow-band filter, the fifth multiplier, the second the input of which is connected to the output of the sixth key, and the low-pass filter, the output of which is connected to the third input of the registration unit, each transmitter is made in the form of series-connected master oscillator, n-tap delay line, in some m-taps of which phase inverters, adder, ( m + 1) whose input is connected to the output of the master oscillator, and the power amplifier, the output of which is connected to the transmitting antenna, the delay time τ3 between adjacent taps of the n-tap delay line is chosen equal to the duration of the radio frequency lsa τe.

Images