RU2715845C9 - Ice and environment monitoring system - Google Patents

Abstract

FIELD: navigation; automated monitoring.SUBSTANCE: invention relates to automated monitoring of state of ice and environment with simultaneous determination of coordinates of own location of complex and transmission of obtained information via radio channel. Measuring and navigation system comprises housing 1, GPS signal receiver 3, control unit 2.1, atmosphere condition determination unit 4, ice cover thickness determining unit 5, accumulator battery state determining unit 6, power supply unit 7 and transceiver unit made in form of first radio stations 8.1. Stationary monitoring station (SMS) is made in form of second radio station 8.2. Each radio station 8.1 (8.2) comprises control unit 2.1 (2.2), synchronizer 16.1 (16.2), PCP generator 17.1 (17.2), carrier frequency synthesizer 18.1 (18.2), phase manipulator 19.1 (19.2), synthesizer 20.1 (20.2) of frequencies of the first heterodyne, first mixer 21.1 (21.2), first intermediate frequency amplifier 22.1 (22.2), first power amplifier 23.1 (23.2), duplexer 24.1 (24.2), transceiving antenna 25.1 (25.2), second power amplifier 26.1 (26.2), second heterodyne frequency synthesizer 27.1 (27.2), second mixer 28.1 (28.2), amplifier 29.1 (29.2), second intermediate frequency, multiplier 30.1 (30.2), band-pass filter 31.1 (31.2), phase detector 32.1 (32.2). GPS signal receiver 3 comprises receiving antenna 9, power amplifier 10, mixer 11, a second intermediate frequency amplifier 12, multiplier 13, band-pass filter 14 and phase detector 15. Ice and environment monitoring system comprises measurement and navigation system (SNC) installed on drifting ice, stationary monitoring station (SMS), GPS-satellites and AES transponder S.EFFECT: technical result is improved reliability of radio telemetry and command information exchange between measurement and navigation system.1 cl, 5 dwg

Description

The proposed system relates to the field of automated monitoring of the state of ice and the environment, while simultaneously determining the coordinates of the complex’s own location and transmitting the received information via a radio channel and can be used as a means of environmental monitoring in the ice movement zone for safe pilotage of vessels along the northern sea route and ensuring safety objects of oil and gas production and hydraulic infrastructure on the shelf and in the coastal zone in the ice seas and in ia ice cover, including drift.

Known systems for monitoring the state of ice and the environment (ed. Certificate of the USSR No. 1.151.107, 1.341.594, 1.376.769, 1.788.487, 1.840.717; RF patents No. 2.080.620, 2.137.153, 2.251. 128, 2.319.205, 2.384.861, 2.404.442, 2.425.400, 2.486.471, 2.487.365, 2.500.031; US patents Nos. 4,231.039, 4,527.160, 4.608.568, 6.204.813; UK patents Nos. 1.494.582, 1.499.388, 2.122.834; French patents Nos. 2.384.268, 2.592.959; German patents Nos. 2.800.074, 2.802.918; Expeditionary activity within the framework of the International Polar Year / Collection of articles . - T. 1: Expeditions of 2007 / under the editorship of A.I. Danilov. - St. Petersburg: AARII. - 2008, p. 1 - 234 and others).

Of the known systems for monitoring the state of ice and the environment, the closest to the proposed one is the "Measuring and navigation system installed on ice" (RF patent No. 2.486.471, G01C 21/00, 2011), which is chosen as a prototype.

The known complex includes a control unit installed in a single thermostatic housing, a unit for determining coordinates by a satellite navigation system, a unit for determining the state of the atmosphere, connected to a transceiver. In addition, the complex includes a power supply unit connected to energy-consuming units. Moreover, the control unit is configured to include units for determining coordinates by a satellite navigation system, determining the thickness of the ice cover and determining the state of the atmosphere, as well as a transceiver for receiving a control signal and transmitting telemetry of the state of the on-board systems of the complex.

The well-known complex provides the exchange of radio telemetry and command information between the measuring and navigation complex, installed on the ice, and a stationary monitoring post.

However, in the conditions of the northern ice seas, multipath propagation of radio waves, organized and unintentional interference, as well as at considerable distances, the reliable exchange of radio telemetry and command information between the measuring and navigation system installed on drifting ice and the stationary monitoring post causes technical difficulties.

To some extent, the problem of reliable exchange of radio telemetry and command information between the measuring and navigation complex and a stationary monitoring post in the conditions of the northern ice seas, multipath propagation of radio waves, organized and unintentional interference can be solved by using complex signals with phase shift keying and pseudo-random tuning of the operating frequency ( HRHF).

An object of the invention is to increase the reliability of the exchange of radio telemetry and command information between a measuring and navigation system installed on drifting ice and a stationary monitoring post in the conditions of the northern ice seas, multipath propagation of radio waves, organized and unintentional interference by using a geostationary satellite repeater of complex and signals from phase manipulation and pseudo-random tuning of the operating frequency.

The problem is solved in that a system for monitoring the state of ice and the environment, containing, in accordance with the closest analogue, a measuring navigation system installed on ice and characterized by the presence of a control unit installed in a single thermostatic housing, a coordinate determination unit for a satellite navigation system, a determination unit the state of the atmosphere connected to the transceiver device, as well as the power supply unit connected to the power-consuming units, and a stationary post monitoring, moreover, the control unit is configured to include units for determining coordinates by a satellite navigation system, determining the thickness of the ice cover and determining the state of the atmosphere, as well as a transceiver for receiving a control signal and transmitting telemetry of the state of the onboard systems of the complex, differs from the closest analogue in that equipped with a geostationary satellite repeater, moreover, the transceiver is made in the form of the first radio station, and the stationary monitoring station fln in the form of a second radio station, each radio station contains a synchronizer, a pseudo-random sequence generator, a carrier frequency synthesizer, a phase manipulator, the second input of which is connected to the second output of the control unit, the first mixer, the second input of which is through the frequency synthesizer of the first local oscillator, sequentially connected to the first output of the control unit connected to the output of the pseudo-random sequence generator, the amplifier of the first intermediate frequency, the first power amplifier, duplexer, input-output One of which is connected to a transceiver antenna, a second power amplifier, a second mixer, the second input of which is connected to the output of the pseudo-random sequence generator through a frequency synthesizer of the second local oscillator, the second intermediate frequency amplifier, a multiplier, the second input of which is connected to the output of the frequency synthesizer of the first local oscillator, a bandpass filter and a phase detector, the second input of which is connected to the output of the frequency synthesizer of the second local oscillator, and the output is connected to the first input of the control unit, frequency ω _g1i and ω _{g2i of} the frequency synthesizers of the first and second local oscillators are spaced by the value of the second intermediate frequency

ω _{g2i -ω g1i} = ω _pr2i ,

where i = 1, 2, ..., M, M is the number of carrier frequencies used,

the first radio station emits complex signals with phase shift keying and pseudo-random tuning of the operating frequency at frequencies ω _1i = ω _pr1i = ω _g2i , and receives - at frequencies ω _2i = ω _pr3i = ω _g1i , and the second radio station, on the contrary, emits complex signals with phase shift keying and operating frequency hopping at frequencies ω _2i and receives - at frequencies ω _1i where ω and ω _{pr1i pr3i} - the first and the third intermediate frequency determining unit coordinate system of the satellite navigation receiver is configured in the form of GPS-signals consisting of serial- but the included receiving antenna, power amplifier, mixer, the second input of which is connected to the output of the frequency synthesizer of the second local oscillator, the second intermediate frequency amplifier, multiplier, the second input of which is connected to the output of the frequency synthesizer of the second local oscillator, bandpass filter and phase detector, the second input of which is connected to the output of the frequency synthesizer of the first local oscillator, and the output is connected to the second input of the control unit.

The geometrical arrangement of the measuring and navigation complex (INC) installed on drifting ice, GPS navigation system satellites and satellite relay S is shown in FIG. 1, where the following notation is introduced: О is the center of mass of the Earth, r is the radius vector of the satellite S, located in a geostationary orbit. A frequency diagram explaining signal conversion is shown in FIG. 2. The structural diagram of the INC is shown in FIG. 3. The block diagram of a stationary monitoring post (PSD) is shown in FIG. 4. A fragment of the time-frequency matrix of the used complex signals with phase shift keying (PSK) and pseudo-random tuning of the operating frequency (PFRCH) is shown in FIG. 5.

The measuring and navigation complex (INC), installed on drifting ice, contains 1 control unit 2.1 installed in a single thermostatically controlled building, a satellite navigation coordinate determination unit 3, an atmosphere state determination unit 4, an ice cover thickness determination unit 5, a state determination unit 6 the battery, the power supply unit 7 and the transceiver device, which is made in the form of a first radio station 8.1. The stationary monitoring post (PSD) is designed as a second radio station 8.2.

Each radio station contains serially connected to the first output of the control unit 2.1 (2.2), a synchronizer 16.1 (16.2), a pseudo-random sequence generator 17.1 (17.2), a carrier frequency synthesizer 18.1 (18.2), a phase manipulator 19.1 (19.2), the second input of which connected to the second output of the control unit 2.1 (2.2), the first mixer 21.1 (21.2), the second input of which through the frequency synthesizer 20.1 (20.2) of the first local oscillator is connected to the output of the PSP generator 17.1 (17.2), the first intermediate frequency amplifier 22.1 (22.2), the first power amplifier 23.1 (23.2), duplexer 24.1 (24.2), the input-output of which is connected to the transceiver antenna 25.1 (25.2), the second power amplifier 26.1 (26.2), the second mixer 28.1 (28.2), the second input of which is connected to the output of the generator 17.1 through the frequency synthesizer 27.1 (27.2) of the second local oscillator (17.2) PSP, amplifier 29.1 (29.2) of the second intermediate frequency, multiplier 30.1 (30.2), the second input of which is connected to the output of the synthesizer 20.1 (20.2) of the frequencies of the first local oscillator, bandpass filter 31.1 (31.2) and phase detector 32.1 (32.2), the second the input of which is connected to the output of the synthesizer 27.1 (27.2) of the frequencies of the second local oscillator, and the output through The key to the second input of the 2.1 (2.2) Control. The control unit 2.1 is connected to the atmosphere state determination units 4, the ice cover thickness determination unit 5, and the battery condition determination unit 6.

Block 3 determining the coordinates of the satellite navigation system is made in the form of a GPS-signal receiver, which consists of a series-connected receiving antenna 9, power amplifier 10, mixer 11, the second input of which is connected to the output of the frequency synthesizer 27.1 of the second local oscillator, amplifier 12 of the second intermediate frequency, a multiplier 13, the second input of which is connected to the output of the synthesizer 27.1 frequencies of the second local oscillator, a bandpass filter 14 and a phase detector 15, the second input of which is connected to the output of the synthesizer 20.1 frequencies of the first hetero ins, and an output connected to the second input of the control unit 2.1. The control unit 2.1 can be performed on the basis of a microprocessor. As the unit 4 for determining the state of the atmosphere can be used the measuring unit of the weather balloon, which is configured to determine wind speed, temperature and air humidity. As the power supply unit 7, a rechargeable battery, preferably configured to be rechargeable, can be used. Block 6 determining the state of the battery 7 provides the transmission of information about its condition to a stationary monitoring post using radio 8.1.

The housing 1 of the complex is mainly made with the possibility of installation from the side of an aircraft or a craft. It is made with a displaced center of gravity, which ensures vertical fixation of the complex on the ice. The housing may contain an anchor system melted into ice due to the action of the battery. The anchor system can be made in the form of a rod, melted into ice. In this case, the rod can be used as a means of measuring the thickness of the ice. In addition, one of the thermocouple elements (the second element is located above the ice surface) can be fixed on the rod, while the electric charge generated by the thermocouple enters the battery. Also, a wind generator mounted on a retractable mast in the upper part of the housing can be used to recharge the battery. The mast can also be used as an antenna for transceivers.

Each used complex has its own individual code (identification number - ID), which is given in all radiograms sent by the complex.

The complex used provides the following functions:

- reception of signals from navigation satellite constellations;

- broadcasting (via satellite channels) of collected data online (at a given time);

- about own coordinate at present;

- about the thickness of the ice on which it is currently located;

- about wind speed, pressure and humidity, temperature (if necessary).

The installation and use of complexes at a given distance provides the ability to create a network of information systems in a system for monitoring the movement of ice and its condition for the safe escort of vessels along the Northern Sea Route and to ensure the safety of oil and gas and hydraulic infrastructure on the shelf and in the coastal zone in the icy seas and in icy cover, including drift.

The proposed system for monitoring the state of ice and the environment works as follows.

Formed complex with a charged battery from the helicopter is dumped on ice. Due to the use of the hull structure (“vanka-vstanka”), the hull 1 is oriented with its heavy lower part toward the ice cover of the water area. After contact with ice, according to the control signal of the control unit 2.1, the anchor system is allocated from the casing 1 and is melted by heating from the battery into the ice surface. After fixing the hull in the ice surface, the mast rises from the hull with a wind generator and sensors for temperature and humidity, as well as wind speed. Simultaneously with the use of the satellite navigation system, the geographical coordinates of the location of the complex are determined.

Each GPS satellite emits at a frequency of ω ₂ = 1575 MHz a special navigation signal in the form of a binary phase-manipulated (PSK) signal, phase-manipulated pseudorandom sequence with a length of 1023 characters

where ϕ _к (t) = {0, π} is the manipulated phase component that displays the law of phase manipulation in accordance with the SRP duration N = 1023.

This signal is received by the antenna 9 and through the power amplifier 10 is fed to the first input of the mixer 11, the second input of which is supplied with the voltage of the synthesizer 27.1 frequencies of the second local oscillator

where i = 1, 2,, M,

M is the number of frequency channels.

At the output of the mixer 11, voltages of combination frequencies are generated. The amplifier 12 is allocated the voltage of the second intermediate frequency

Where

ω _pr2i = ω _{g2i -ω 2} - the second intermediate frequency;

ϕ _pr2i = ϕ ₂ -ϕ _g2i ,

which is supplied to the first input of the multiplier 13. The second input of the last voltage is supplied u _g2i (t) of the synthesizer 27.1 frequencies of the second local oscillator. The output of the multiplier 13 is formed voltage

Where

which is a complex PSK signal at a frequency ω _{g1i of the} synthesizer 20.1 of the frequencies of the first local oscillator, is allocated by a band-pass filter 14 and fed to the first (information) input of the phase detector 15. At the second (reference) input of the phase detector 15, the voltage of the frequency synthesizer 20.1 is supplied as the reference voltage first local oscillator

As a result of synchronous detection, a low-frequency voltage is generated at the output of the phase detector 15

Where

which goes to the first input of the control unit 2.1, where the location of the INC installed on drifting ice (latitude, longitude) is determined. For this, the presence of three satellites in the radio visibility zone is sufficient.

The information obtained in the control unit 2.1 on the geographical coordinates of the INC, the ice thickness, wind speed, pressure and humidity, the state of the battery is converted into a modulating numerical code M ₁ (t) and transmitted via radio 8.1 to a stationary monitoring post. To do this, using the control unit 2.1, the synchronizer 16.1 and the PSP generator 17.1 are turned on, which, in turn, controls the operation of the synthesizer 18.1 carrier frequencies, the synthesizer 20.1 frequencies of the first local oscillator and the synthesizer 27.1 frequencies of the second local oscillator.

At the output of the synthesizer 18.1 carrier frequencies, a grid of high-frequency oscillations of various carrier frequencies is sequentially formed in time:

where U _i , ω _i , ϕ _i , T _c - amplitudes, carrier frequencies, initial phases and signal duration;

i = 1, 2, ..., M,

M is the number of carrier frequencies used (number of frequency channels) (Fig. 5);

M = Δω _c / Δω ₁ ,

Δω _c is the bandwidth of the spread spectrum of the signal used;

Δω ₁ is the bandwidth of one frequency channel;

t _c - the time interval between frequency switching, characterizes the operating time at one carrier frequency.

Depending on the ratio of the operating time at one frequency t _c and the duration of the information symbols τ _{e, the} pseudo-random tuning of the operating frequency (PFRCH) can be divided into intersymbol, character, and character. With the intersymbol frequency hopping, n information symbols (n≥2) are transmitted at the same frequency, with t _c = n⋅τ _e .

As an example in FIG. 5 shows a fragment of the time-frequency matrix of a complex PSK _n signal with frequency hopping. In this case, n was chosen equal to 4 (t _c = 4⋅τ _e ), the squares with different oblique shading indicate different information symbols with different phases (0, π).

The generated high-frequency oscillations u _i (t) sequentially in time arrive at the first input of the phase manipulator 19.1, the second input of which is supplied from the second output of the control unit 2.1, the modulating code M ₁ (t).

At the output of the phase manipulator 19.1, a complex PSK signal is formed

where ϕ _k1 (t) = {0, π} is the manipulated phase component that displays the phase manipulation law in accordance with the modulating code M ₁ (t), and ϕ _k1 (t) = const for kτ _e <t <(k + 1 ) τ _e and can change abruptly at t = k⋅τ _e , i.e. at the borders between elementary premises (k = 1, 2, ..., N-1); τ _e , N is the duration and number of chips that make up a signal of duration T _c (T _c = N⋅τ _e ), which is fed to the first input of the mixer 21.1. At the second input of the mixer 21.1 from the output of the synthesizer 20.1 of the frequencies of the first local oscillator voltage is applied sequentially in time:

which are formed sequentially in time using the generator 17.1 PSP.

At the output of the mixer 21.1, voltages of combination frequencies are generated. Amplifier 22.1 distinguishes voltages of only the first intermediate (total) frequency

Where

ω _pr1i = ω _i + ω _g1i - the first intermediate (total) frequency (Fig. 2);

ϕ _pr1i = ϕ _i + ϕ _g1i ,

which, after amplification in the power amplifier 23.1 through the duplexer 24.1, enter the transceiver antenna 25.1, are broadcast by it in the direction of the satellite, are re-emitted by it at the same frequency with the same phase relationships, they are received by the transceiver antenna 25.2 of the stationary monitoring station and through the duplexer 24.2 and the amplifier 26.2 power is supplied to the first input of the mixer 28.2, the second input of which is supplied with voltage u _g1i (t) of the synthesizer 27.2 of the frequencies of the first local oscillator (i = 1, 2, ..., M). At the output of the mixer 28.2, voltages of combination frequencies are generated. Amplifier 29.1 distinguishes the voltage of the second intermediate (differential) frequency

Where

ω _pr2i = ω _{pr1i -ω g1i} is the second intermediate (difference) frequency;

ϕ _pr2i = ϕ _pr1i -ϕ _g1i ,

which go to the first input of the multiplier 30.2. The voltage of the synthesizer 20.2 of the frequencies of the first local oscillator is supplied to the second input of the multiplier 30.2:

At the output of the multiplier 30.2 voltage is formed

Where

_g1i ω = ω _ave

which are allocated by the band-pass filter 31.2 and fed to the first (information) input of the phase detector 32.2. At the second (reference) input of the phase detector 32.2, voltages u _g1i (t) of the synthesizer 27.2 of the frequencies of the second local oscillator are supplied. As a result of synchronous detection, low-frequency voltages are generated at the output of the phase detector 32.2

Where

which are input to the control unit 2.2.

Subsequently, periodically, according to the program embedded in the control unit 2.1, or according to the control signal from the stationary monitoring station, the parameter measurement operation is repeated. To transmit the corresponding commands in the control unit 2.2, a modulating code M ₂ (t) is generated, which is fed to the second input of the phase manipulator 19.2. The first input of the latter is supplied with high-frequency oscillations from the output of the carrier synchronizer 18.2, controlled by the generator 17.2 PSP, to the control input of which a synchronizer 16.2 is connected

At the output of the phase manipulator 19.2, complex PSK signals are formed

where ϕ _k2 (t) = {0, π} is the manipulated phase component that displays the phase manipulation law in accordance with the modulating code M ₂ (t), which are fed to the first input of the mixer 21.2. The voltage u _g2i (t) of the frequency synthesizer 20.2 of the first local oscillator is successively applied to the second input of the mixer 21.2. At the output of the mixer 21.2, voltages of combination frequencies are generated. Amplifier 22.2 distinguishes the voltage of the third intermediate frequency

Where

ω _pr3i = ω _{g2i -ω i} = ω _2i is the third intermediate (difference) frequency;

ϕ _pr3i = ϕ _g2i -ϕ _i ,

which, after amplification in the power amplifier 23.2 through the duplexer 24.2, enter the transceiver antenna 25.2, are emitted by it in the direction of the satellite repeater at the frequency ω _2i , are reradiated by the onboard equipment of the satellite repeater with preserving the phase relations, are received by the antenna 25.1 of the IRC and through the duplexer 24.1 and amplifier 26.1 power is supplied to the first input of the mixer 28.1, the second input of which is supplied sequentially in time to the voltage u _g2i (t) of the synthesizer 27.1 of the frequencies of the second local oscillator. At the output of the mixer 28.1, voltages of combination frequencies are generated. The amplifier 29.1 allocated voltage of the second intermediate frequency

Where

ω _pr2i = ω _{g2i -ω 2i} is the second intermediate (difference) frequency;

ϕ _6i = ϕ _pr3i -ϕ _g2i ,

which go to the first input of the multiplier 30.1. The second input of the latter is supplied with voltage u _g2i (t) of the synthesizer 27.1 of the frequencies of the second local oscillator. At the output of the multiplier 30.1 voltage

Where

which are allocated by the band-pass filter 31.1 and fed to the first (information) input of the phase detector 32.1. At the second (reference) input of the phase detector 32.1, voltages u _g1i (t) of the frequency synthesizer 20.1 of the first local oscillator are supplied as reference voltages. As a result of synchronous detection, low-frequency voltages are generated at the output of the phase detector 32.1

Where

in proportion to the modulating code M ₂ (t), which are fed to the second input of the control unit 2.1, where the commands and recommendations of the stationary monitoring station are implemented.

If all the parameters measured by blocks 4, 5 and 6 correspond to the conditions of normal operation of the measuring and navigation complex, the transmission of radio telemetry information from the INK to the stationary monitoring post occurs at a predetermined frequency (for example, once every 60 minutes).

If at least one of the measured parameters exceeds a predetermined level or the deviation of the location of the INC from the planned location, the period between transfers is reduced.

In the event of an emergency, discrete information from the INC is transmitted continuously.

When the controlled parameters return to acceptable values, as well as the correspondence of the location of the INC to the planned location, the period between discrete information transfers will again be increased.

The mode of transmitting discrete information by the control unit 2.1 can also be changed by the decision of a stationary monitoring station. The battery charging system is always on.

Thus, the proposed system for monitoring the state of ice and the environment, in comparison with the prototype and other technical solutions of a similar purpose, provides an increase in the reliability of the exchange of radio telemetry and command information between the measuring and navigation complex installed on drifting ice and the stationary monitoring post in the northern ice seas, multipath propagation of radio waves, organized and unintentional interference. This is achieved through the use of a geostationary satellite repeater and complex signals with phase shift keying (PSK) and pseudo-random tuning of the operating frequency (PFRCH).

The main advantage of the duplex method of communication through a geostationary satellite repeater is that it provides reliable duplex radio communications measuring and navigation complex and a stationary monitoring station, spaced over long distances. It excludes the length of the signal path. Therefore, its accuracy mainly depends on the parameters of the onboard repeater and the type of signals used.

The operating frequency of the used PSK signals and the local oscillator frequencies are tunable over a wide range in accordance with pseudorandom codes known at the measuring and navigation complex and stationary monitoring post and unknown to the jammer.

The strategy to combat unintentional and organized interference consists in “avoiding” the signals of the duplex radio communication system from the effects of interference by pseudo-random tuning of the operating frequency and in “confronting” them by phase manipulating the carrier frequency with a pseudo-random sequence.

Therefore, when protecting against interference, an important characteristic is the actual operating time at one frequency t _c . The shorter this time, the higher the likelihood that the signals of a duplex radio communication system with frequency hopping will not be affected by organized interference.

The noise immunity of a duplex radio communication system through a geostationary satellite repeater depends not only on the operating time at a single frequency, but also on the type of interference and their power, useful signal power, and receiver structure.

Used complex PSK signals with frequency hopping have energy, structural, informational, temporal and spatial 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, a complex PSK signal with frequency hopping at the receiving point may be masked by noise and interference. Moreover, the energy of a complex PSK signal is by no means small. It is simply distributed over the time-frequency domain so that at each point in this area the signal power is less than the power of noise and interference.

The structural secrecy of complex PSK signals with frequency hopping is caused by a wide variety of their forms and significant ranges of parameter changes, which makes it difficult to optimize or at least quasi-optimal processing of complex PSK signals with frequency hopping and an a priori unknown structure in order to increase the sensitivity of receivers.

Information secrecy is determined by the ability to withstand measures of electronic intelligence aimed at revealing the meaning of the messages exchanged between the measuring and navigation complex and the stationary monitoring post.

The temporary secrecy of a duplex radio communication system is determined by its temporary radiation modes.

The spatial secrecy of a duplex radio communication system depends on the signal power, the type and parameters of the radiation patterns of the transceiver antennas.

Complex PSK signals with frequency hopping allow you to apply a new type of selection - structural selection. This means that it becomes possible to separate signals operating in the same frequency band and at the same time intervals.

Among other problems, the solution of which to a large extent depends on the further progress of duplex radiocommunication facilities, should include the problem of establishing reliable communication between the INC and the stationary monitoring post in the presence of the 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.

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 the use of several carrier frequencies and its good correlation properties, complex PSK signals with frequency hopping can be “folded” into a narrow pulse whose duration is inversely proportional to the used bandwidth. Choosing such a frequency band so that the duration of the “convoluted” pulse is shorter 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 receiving complex PSK signals with frequency hopping. Thus, the indicated problem gets a fundamental solution.

The main feature of the proposed system, which is created using measuring and navigation systems installed on drifting ice, is the ability to provide precise technical control of the state of ice, its thickness, which makes it possible, using special software products, to predict the time and quality of formation of hummocks, ice displacement and formation impassable for the icebreaker fleet of ice conditions.

Using the developed system makes it possible to increase the level of safe pilotage of ships in ice and the safety of oil and gas and hydraulic infrastructure facilities on the shelf and in the coastal zone in ice seas and in conditions of drifting ice cover.

Claims (3)

An ice and environmental monitoring system containing a measuring and navigation system installed on ice and characterized by the presence of a control unit installed in a single thermostatic housing, a satellite navigation coordinate determination unit, an atmosphere state determination unit connected to a transceiver device, and also a power supply unit connected to power-consuming units, and a stationary monitoring post, and the control unit is configured to turn on the unit determining coordinates using a satellite navigation system, determining the thickness of the ice cover and determining the state of the atmosphere, as well as a transceiver for receiving a control signal and transmitting telemetry of the state of the onboard systems of the complex, characterized in that it is equipped with a geostationary satellite repeater, the transceiver being made in the form of the first radio stations, and a stationary monitoring post in the form of a second radio station, each radio station contains serially connected to the first The ode of the control unit is a synchronizer, a pseudo-random sequence generator, a carrier frequency synthesizer, a phase manipulator, the second input of which is connected to the second output of the control unit, the first mixer, the second input of which is connected to the output of the pseudo-random sequence generator through the frequency synthesizer of the first local oscillator, the first intermediate frequency amplifier, the first a power amplifier, a duplexer, the input-output of which is connected to a transceiver antenna, a second power amplifier, a second mixer, a second input apart from the frequency synthesizer of the second local oscillator, a second intermediate frequency amplifier, a multiplier, the second input of which is connected to the output of the frequency synthesizer of the first local oscillator, is connected to the output of the pseudo-random sequence generator, a bandpass filter and a phase detector, the second input of which is connected to the output of the frequency synthesizer of the second local oscillator, and the output connected to the first input of the control unit, the frequency ω ω _g1i and _g2i synthesizers of frequencies of the first and second local oscillators spaced apart by the value of the second intermediate portions you ω _g2i - ω _g1i = ω _np2i , where i = 1, 2, ..., M, M is the number of carrier frequencies used, the first radio station emits complex signals with phase shift keying and pseudo-random tuning of the operating frequency at a frequency ω _1i = ω _np1i = ω _r2i , and receives at a frequency ω _2i = ω _np3i = ω _g1i , and the second radio station, on the contrary, emits complex signals with phase shift keying and pseudo-random tuning of the operating frequency at frequencies ω _2i , and receives at frequencies ω _1i , where ω _np1i and ω _np3i are the first and third intermediate frequencies, block determination of coordinates by satellite navigation system is made in the form of GPS signal receiver, consisting of a series-connected receiving antenna, power amplifier, mixer, the second input of which is connected to the output of the frequency synthesizer of the second local oscillator, the second intermediate frequency amplifier, multiplier, the second input of which is connected to the output of the frequency synthesizer of the second local oscillator, bandpass filter and phase a detector, the second input of which is connected to the output of the frequency synthesizer of the first local oscillator, and the output is connected to the second input of the control unit.

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