RU2390098C2 - Coordinate-information support method for underwater mobile objects - Google Patents

Abstract

FIELD: information technology.

SUBSTANCE: invention involves multiple use of laser channels of inter-satellite measurements and communication, transmission of signals from satellites to an underwater object (UO) and back, as well as design of methods for adapting these channels to the effect of meteorological factors and sea waves. The invention can be used in solving crucial problems for underwater reception of control signals and navigation underwater objects (submersible vehicle), lying in increasing their operation efficiency when working in the shelf area or in open areas of the ocean without rising to the surface.

EFFECT: efficient control of underwater objects while meeting strict requirements to their coordinate support during special operations.

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Description

The invention relates to communication and navigation systems and can be used for prompt delivery of control commands and correction of inertial navigation systems of autonomous inhabited underwater objects (software), for example, underwater vehicles located at working depths of immersion, as well as for the delivery of service information from immersed software control centers (underwater, surface, ground or air based).

There is a known method of delivering commands to submerged submarines (PL) using leakage of extremely low frequency (ELF) radio waves propagating in the natural ground-ionosphere waveguide (see, for example, the article “Long-range communication at extremely low frequencies”, TIIER , 1974, vol. 62, pp. 5-30), which was implemented in the Sanguine project and since 1986 has been used in the interests of combat control of submarines of the US Navy.

In a known manner:

- from a stationary ground control center, omnidirectional radiation of a frequency-manipulated, in accordance with the symbols of the binary convolutional code, radio signal is carried out at an extremely low (usually less than 100 Hz) carrier frequency;

- on a submarine, energy leaks into the ocean of an electromagnetic wave of extremely low frequency, which propagates from a ground control center in a ground-ionosphere waveguide;

- compensate for the effect of the ocean on received radiation by amplifying the amplitudes of the “high-frequency” signal components and correcting their phases;

- suppress interference from power plants of the submarine by the method of tracking notch;

- smooth out atmospheric noise by introducing nonlinear bias in the received ELF signal;

- perform consistent filtering, in which each sample of the received mixture of signal and noise is correlated with in-phase and quadrature copies of the transmitted signals;

- demodulate channel symbols by combining their output signals after matched filtering and using a pseudo-random sequence that is identical to the sequence of the transmitter of the ground center;

- evaluate the phase of the received signal and compensate for phase errors;

- restore the original code sequence and decode the transmitted command.

The main disadvantages of this method:

- low stealth;

- long duration of the communication session;

- low security against unauthorized interception of signals and from interference suppression;

- high vulnerability of a large-sized transmission center from means of armed suppression;

- the impossibility of two-way exchange of information and, therefore, the impossibility of receiving information necessary for effective management of information from a submarine;

- extremely low throughput (not more than 1 baud) of one-way (from the center to all submarines located in the oceans) command transmission;

- the impossibility of solving the correction task of the ship's inertial complex by ELF signals.

The combination of the main disadvantages of the known method excludes its use in extreme conditions.

The closest in technical essence is the way to navigate underwater objects at working depths (copyright certificate 265188 for application No. 3181100/25832 of 04.25.83).

In a known manner:

- transmit laser navigation-connected signals from spacecraft to the ocean;

- determine the current location of the spacecraft (SC) and the discrepancy of the onboard time scale (BSA) of this device with the system time of the GLONASS system;

- enter into the transmitted laser signals information about the location of the spacecraft and the corrections of the onboard time scale;

- detect and decode laser signals from three or more spacecraft on an underwater object;

- measure the pseudorange between the underwater object and the spacecraft;

- determine the coordinates of the underwater object and the amendment for the ship’s time scale relative to the system time of the GLONASS space navigation system (SSC) based on the solution of the pseudo-rangefinder task.

The known method allows to solve the key problem of covert delivery of control commands to the software and providing the underwater object with data for a high-precision solution to the navigation problem. However, this method has significant disadvantages.

To implement the proposed method requires unacceptably high financial costs associated with the need to deploy a grouping of navigation spacecraft (NSC) with powerful laser transmitters, providing irradiation of a significant part of the World Ocean.

The known method does not allow covertly and expeditiously to receive heterogeneous information with shipped software, including data on the technical condition of the software, receipts on receipt of operational management commands, as well as other information necessary for making management decisions.

The technical stability of the coordinate support of underwater objects based on laser measurements of navigation parameters relative to spacecraft depends on the technical stability of the ephemeris-time support (EVO) of these devices.

In the known method, the EVO is provided by the GLONASS system.

The weakest element of this system is the radio-technical stationary means of the ground-based control complex, which can be eliminated or suppressed by deliberate actions.

In this case, the accuracy of the EVO, and therefore the coordinate support of the software in a few days will become unacceptably low.

The main contribution to the increase in coordinate support errors, as ground support data become obsolete, is made by the radial component of the ephemeris error and the divergence of the onboard time scales of GLONASS navigation satellites. The lateral components of the satellite’s location (nodes and inclination of the orbits, respectively) allow highly accurate forecasting for several months.

The limitation of the application of the known method is associated with the attenuation and distortion of laser navigation-connected signals when passing through the clouds. The consequences of these effects are: a decrease in the transmission speed and reliability of messages when delivering control commands, a decrease in the accuracy of measuring the pseudorange, a decrease in the permissible software immersion depth when receiving laser signals, an increase in the resolution of observations, etc.

Thus, the main disadvantages of this method are:

1. The lack of effectiveness of information support.

2. Insufficient technical stability and accuracy of coordinate support.

3. High vulnerability from atmospheric factors, in particular, from the shading of clouds provided by the areas of the World Ocean.

4. High cost.

The aim of the invention is to increase the efficiency of information support, as well as the accuracy and technical stability of coordinate support, reducing vulnerability to weather factors and cost.

This goal is achieved by the fact that the known method in which:

- transmit interrogation laser navigation-connected signals from the spacecraft to the ocean;

- detect and decode laser interrogation navigation-connected signals from three or more spacecraft on the underwater vehicle;

- using decoded signals determine the numbers of satellites and solve the problem of mutual identification;

- measure the pseudorange between the underwater vehicle and spacecraft;

- determine the coordinates of the underwater object and the amendment for the ship time scale relative to the system time of the space navigation system based on the solution of the pseudo-range navigation task;

- additionally enter the following procedures:

- on the underwater object, the angular position of the glare formed during the passage of the laser signals of the satellites through the excited surface of the water is recorded, the brightest of them are selected, the response laser signals are emitted in the directions of the selected glare, the time between the moment of the last request signal reception and the moment of the first response pulse emission is recorded;

- on the satellites of the orbital constellation, based on cloud analysis, they emit signals through gaps in the clouds, receive and decode the response signals of the underwater object, measure the time interval between the moment of emission of the last request pulses and the first response pulse, transmit the measurement results, introducing them into the navigation signal frame in the direction the arrival of the response signal, receive and decode this signal on the underwater object and determine the true range between the satellite and the underwater object, taking into account the measured x delays, immersion depth of the underwater object and the direction of radiation of the response signal of the underwater object;

- determine the time correction of the onboard clock of the underwater object relative to the satellite clock based on a comparison of the pseudo- and true ranges;

- on satellites emit pulsed laser signals attached to the on-board time scale in the directions of several satellites in their orbital plane and several satellites in adjacent orbital planes, measure inter-satellite ranges and shifts of the on-board time scales based on the total-difference relations of time intervals between the moments of emission of natural pulses and receiving laser pulses from neighboring spacecraft, tied to the corresponding time points relative to the airborne scales;

- determine the corrections of the radial components of the ephemeris based on the inter-satellite ranges, introduce these corrections into the frames of the interrogation signals emitted in the direction of the served region of the World Ocean;

- the decoded information extracted from the response signals of the underwater object is laid down in the inter-satellite laser signal format and transmitted through a chain of satellites to a predetermined region where the control center for the actions of underwater objects is located.

The figure 1 presents the General scheme of navigation-connected lines, explaining the sequence of actions of this method of coordinate-time support of underwater objects,

where: 1 _{i, j, k} are the satellites of the orbital constellation (i ≠ j ≠ k; i, j, k∈ {1, 2 ... 24}),

2 - submerged underwater object,

r - inter-satellite distances,

Δt are the relative shifts of the onboard time scales of the corresponding pairs of satellites,

R is the distance between the satellite and the underwater object.

The figure 2 presents an example of the structure of satellite laser equipment that implements the operation of this method,

where: 3 - astrosystem,

4 - inter-satellite laser measuring and communications system (MLISS),

5 - laser information-coordinate support system (LSIKO),

6 - on-board digital computer containing a standard of frequency and time,

7 - coordinate matching system (SSC),

8 - laser range finder (LD),

9 - information transfer system (SPI),

10 - optical-electronic direction finder (OEP),

11 - guidance system (optical-mechanical drive),

12 - guidance control system and tracking (command generator for drive 11),

13 - computer control system,

14 - panel reflectors,

15 - direction finder

16 - laser transmitting system (LPS),

17 - photodetector system (FPS),

18 - guidance system (SN),

19 is a wide-angle coordinator (HQ),

20 - cloud cover sensor (TO).

The figure 3 presents an example of a structural diagram of the laser equipment of an underwater object, which allows you to implement the actions of this method,

where: 21 - software guidance system (SPN),

22 - optical system (OS),

23 - information-measuring photodetector (IIPP),

24 - photodetector precision guidance system (FPSTI),

25 - precision guidance device (UTN) medical facilities,

26 - laser transmitting device (MPI),

27 is a device for processing accurate guidance signals (USOSTN),

28 - time interval meter (IVI),

29 - information signal processing system (SOIS),

30 - computer control system (VUS),

31 - meter transparency of water (IPV).

Information is delivered to the underwater object and the formation of an underwater laser navigation field for it in a given region of the ocean (an area of at least ten thousand square kilometers) is carried out by all satellites in the visibility zone of which there is a provided area.

All satellites solve the problem of orienting laser equipment with minute accuracy.

Existing and projected means of orientation of the GLONASS system are based on the use of sensors from the Sun and the Earth. The technological limit of accuracy is tens of arc minutes. The increase in accuracy in this case is tens of arc minutes. Improving accuracy is possible through the use of direction finding of navigation stars (using astrosystem 3), as well as direction finding (device 10) of neighboring satellites using the signals of a laser range finder 8 (or a connected transmitter of system 9).

As a guide for navigation, ground-based laser beacons can serve, in this case, the reference direction is determined by the direction finder 15.

Ground beacons and “neighboring” grouping devices can serve as high-precision sources of information about its current orientation. Even if the relative position of the satellites is known from the long-term (rough) grouping almanac, it is possible to solve the orientation problem with errors not exceeding tens of arc seconds.

To solve the task of refining the orientation, the following operations are necessary.

Based on the ephemeris information, the inter-satellite vector is determined, i.e. the direction (azimuth and elevation angle) to the “neighboring” device is calculated relative to the coordinate system associated with the satellite (usually OX is directed to the center of the Earth, OY is perpendicular to the orbit plane, OZ complements the system to the right).

According to the laser radiation of the neighboring satellite device 8 in the direction of the orienting device, the pseudo-azimuth and the pseudo-angle of the place are measured in the device 10 with respect to the associated coordinate system formed by the device’s orientation and stabilization system (SOS).

Based on the comparison of the calculated and measured directions to the two “neighboring” satellites in the device 6, the orientation errors of the SOS are determined, i.e. Euler angles are calculated between the calculated (true) and current, formed according to the SOS data, coordinate trihedra.

A similar solution to the orientation problem with second and subsecond accuracy is possible using astro-orientations.

Using the sighting system 3 of two (or more) spaced (for example, in azimuth) navigation stars, it is possible to reproduce a location-invariant (analytical) coordinate system, i.e. coordinate systems with axes parallel to the axes of the frame in which the astronomical catalog is reproduced. The algorithm for determining the orientation of the analytical trihedron - x y z relative to the coordinate axes associated with the spacecraft (for example, with the center of mass and the inertia axes of the apparatus) - x _with y _with z _c is given by the system of equations

Where

;

;

;

;

x _ac = cosh cosA

y _ac = cosh sinA

Here h _l A _l - the altitude and azimuth of the l-th navigation star, given by the astronomical catalog,

и

- псевдовысота и псевдоазимут l-й звезды, определенные относительно связанной системы координат,

and

- pseudo-height and pseudo-azimuth of the l -th star, defined with respect to the associated coordinate system,

h and A are the altitude and azimuth of the l -th star, as measured by the spacecraft astrosystem,

- вектор, характеризующий положение астросистемы на космическом аппарате относительно связанного репера х_с у_с z_c,

is a vector characterizing the position of the astrosystem on the spacecraft relative to the bound frame x _s y _s z _c ,

γ _ac - mutual roll (torsion angle) between the bound frame of the astrosystem,

φ, Ψ, ν are the Euler angles between the analytic and connected trihedra.

The potential accuracy limit of the analytical orientation is limited by the uncertainties of the parameters of the navigation stars relative to the geocentric basis, as well as the uncertainties of the geocentric basis itself (the equatorial coordinate system), which are caused by the instabilities of the Earth's rotational motion and the rotation of the planets around the Sun.

The theoretical limit of accuracy of orientation using the principle of the equatorial reference system corresponds to the level of 0.1 angle. sec Studies are known with the aim of constructing transatmospheric coordinate bases that are free from the shortcomings of geocentric coordinate systems (Hipparcos program (USA), etc.).

There are as many coordinate systems in the laser complex as there are angle measurements. To reproduce angular measurements in the analytical benchmark, it is necessary to ensure that these measurements are linked to the associated coordinate system.

The analytical angular coordinates of the ground beacons and neighboring grouping devices are determined by the algorithm specified by the table.

и

обозначены связанные координаты, а черезAcross

and

associated coordinates are indicated, and through

α and β are analytical angular coordinates.

The guidance of satellite equipment 5 to a given region of the ocean is carried out according to the program generated in devices 6 and 13, taking into account the data of the multispectral cloudiness sensor 20.

If the probability of clearance is less than 0.6, then radiation is interrupted (by clearance is meant an atmospheric path with integral transmission in one direction from the satellite to the water surface of at least 1%).

The guidance program of equipment 5 on a given area in the ocean can be set based on the relations:

;

;

;

;

;

;

x _ai = X ₀ -X _0i

y _ai = Y ₀ -Y _0i

z _ai = Z ₀ -Z _0i

where X ₀ Y ₀ Z ₀ - the assumed, for example, grouping almanac, the geocentric coordinates of the determined spacecraft;

X _0i Y _0i Z _0i - geocentric coordinates of the i-th object;

a _km - components of the coordinate transformation, which are determined by the angles of rotation between the analytical and associated triangles associated with the spacecraft.

In the interest of improving reliability in emergency situations, the functions of inter-satellite measurements can be provided in equipment 5. In this case, the zone of its re-targeting (i.e., the range of working angles of the drives 18) should be ± 90 ° in each coordinate (i.e., hemisphere) .

On all satellites participating in the coordinate-information support of a given area, the on-board clock is updated based on inter-satellite rangefinding measurements (using system 4).

The technology for updating the frequency-time corrections (CVP) is based on counter-measurements of pseudorange between pairs of spacecraft.

Intersatellite laser measurements can provide compensation with nanosecond accuracy for discrepancies between the simulated (in the form of a linear polynomial) values of the FWP and their true values. These errors, if they are not compensated, are directly included in the errors of consumer measurements (software).

When measuring at intervals of 5 to 10 minutes, compensation for any evolution of the on-board clock can be guaranteed and the stability requirements for the on-board frequency standards can be significantly reduced.

Range measurements are carried out in the device 8 based on the measurement of time intervals τ between the moments of emission of their laser pulses and the reception of signals from a neighboring satellite.

Information is transmitted by the device 9 by the method of relative time-pulse modulation OVIM (PIM). In this case, from 18 to 27 bits of information can be transmitted by each laser pulse.

The calculated relations for estimating the range r and the shift of the scales Δt are given by the relations:

;

;

;

;

where τ _s is the delay measured on the satellite l _s .

Intersatellite laser rangefinder measurements allow autonomous correction of ephemeris errors in software coordinate support.

The technology of autonomous correction of satellite ephemeris based on inter-satellite measurements can be based on the well-known method of partial solution of the ephemeris problem, in which the position of the spacecraft along the orbit is refined.

The method is implemented when two conditions are met:

a) the line of sight is close to the direction orthogonal to the speed of one of the interacting satellites (reference);

b) the line of sight is close to the direction of speed of another (estimated) satellite.

In this case, only the transversal component of the estimated satellite is adjusted. According to the measurements obtained at selected time instants, a polynomial is constructed in device 6 to correct the transversal component of the estimated spacecraft, based on which the correction is calculated in device 13 and inserted into the navigation-connected laser signals of device 16 (LPS) of system 5.

The multichannel consumer laser equipment (PA) in photo reception mode accompanies the corresponding navigation spacecraft (NSC) of the working constellation. The escort program is formed from data from the almanac of the orbital group, the ship’s inertial complex, and the depth of immersion of the aircraft.

The guidance program of the PA equipment, which is formed by devices 30 and 24 at the expected position of the spacecraft, is defined by the relations

;

;

;

;

;

;

;

;

,

,

where A (t) and µ (t) are the topocentric azimuth and angular height of the spacecraft;

направлена на северный полюс по касательной к меридиану подводного объекта, ось

- по внешней нормали к местной вертикали ПО, а ось

дополняет систему до правой);ε, η, ξ are the topocentric coordinates of the spacecraft (axis

directed to the north pole along the tangent to the meridian of the underwater object, the axis

- along the external normal to the local vertical of PO, and the axis

complements the system to the right);

λ (t), Θ (t) - the longitude and latitude of the expected (unspecified) position of the software are determined according to the ship’s autonomous navigation complex;

- геоцентрические координаты расчетных местоположений КА и ПО;X _KA Y _KA Z _KA and

- geocentric coordinates of the calculated locations of the spacecraft and software;

- звездное время в среднюю гринвичскую полночь для заданной даты;

- Star time at midnight Greenwich midnight for a given date;

ω is the angular velocity of the Earth.

The permissible error of coarse (software) guidance of underwater equipment (using devices 22-26) is determined mainly by the spread in the directions of arrival of the weakly scattered component of the satellite signal, because other components of this error are small in comparison with this scatter. This scatter is caused by sea waves and amounts to units of degrees, therefore, the permissible error W of the software guidance of the submarine equipment (Figure 3) is ± (1-2 °).

On the software in devices 23, 24 and 29, the satellite query signal is recorded and decoded (for example, by measuring the time intervals between laser pulses) in order to identify the satellite number and solve the identification problem, then adaptive guidance (devices 25-27) is carried out at the registration point a bright flare of the underwater light field of the interrogation signal and the radiation of the response code signal by the device 26.

The essence of adaptive guidance consists in the asynchronous quasi-biased rotation of the interrogated laser beam (NOL) consists in recording the angular position of the glare (coordinate-sensitive receiver 24), formed by the passage of the navigation satellite signals (from the device 16 - LPS) through the excited surface of the water, selecting the brightest of them and radiation in the directions of the selected glare of the response pulse laser signal by the transmitter 26.

, где d - диаметр лазерного пучка (d≤10^-2 м), F - фокусное расстояние водяной «линзы» (F=5…50 м).The statistical description of the flare field is based on the representation of the ocean surface as a combination of astigmatic water “lenses” with random sizes and alternating optical power. These lenses create a system of underwater glare - real and imaginary images of the emitter (interrogator on the satellite). Due to the reversibility of the photon propagation paths, the response radiation after refraction on the surface of the water with a high probability (0.7-0.9) will be directed to the satellite. The speed requirement for adaptive guidance equipment is determined by the time of “freezing” of the excited surface of the ocean, which, depending on the type of wave, is from 0.1 to 30 ms. The maximum divergence of a laser beam emerging from under water in the direction of the satellite is limited by

where d is the diameter of the laser beam (d≤10 ^-2 m), F is the focal length of the water "lens" (F = 5 ... 50 m).

The value ΔΘ = (0.6 ... 6) ang. minutes determines the spatial secrecy of the response radiation. Temporary secrecy is determined by the duration τ of laser pulses, which is (0.5 ... 5) 10 ^-9 s. The total glow time of the spot (d≤10 ^-2 m) on the ocean surface during the navigation session is t = N · τ (here N is the number of response pulses of the laser code-pulse signal, as a rule, N≤100, t≤ (0, 05 ... 0.5) μs).

There are no ways to eliminate the adaptive guidance conditions by the NOL method, because no known means can either cancel the principle of reciprocity in optics, or eliminate the ocean waves.

Unlike radio equipment with towed antenna output devices (VBAU), interference suppression of adaptive laser software is practically impossible, because the means of effective suppression of this laser equipment that implements the NOL method should be within the diagram of the underwater receiver and emit interference laser pulses tied to satellite signals with unacceptably high accuracy (i.e., at the current technical level, means of interference suppression of laser NOL channels cannot be created).

At the time of the emission of each last request pulse, the range counter of the device 13 is launched on the spacecraft; the time between the reception of the last pulse of the request signal and the moment of emission of the first response pulse is recorded on the software in the device 28. This (response) impulse, arriving at the NKA, is used to stop the range counter.

The delay between the end of the radiation of each request signal and the moment of receiving the first response pulse is transmitted to the software in a connected mode (via devices 16, 22, 23, 29 and 30. The range between the software and the spacecraft is estimated in device 30 (CCS) on the software using the formula:

,

,

where τ _s - the delay between the request and response pulse, measured on the spacecraft,

τ _a - the hardware delay between the reception of the interrogation pulse and the radiation of the response is measured on the software,

h is the immersion depth of the software,

α - direction to the place of registration of glare relative to the underwater (for example, topocentric) horizon,

with and _in - the speed of light in air and seawater.

Information on the fact of receiving a response signal can be transmitted through secretive inter-satellite channels of system 4 to any satellite of the group and, if necessary, by using system 5 in any of the ground, air, orbital or underwater control centers. Based on this information, a task may be issued to deliver interrogation signals to a given region by all the spacecraft in which it is in the field of visibility before receiving a command to end the session from the software (or from the control center). According to this information, procedures can be launched to misinform the enemy, for example, by creating, with the help of orbital laser means, a system of 5 background-signaling situations simulating sessions with software in false areas.

Based on the measured ranges of up to two or more spacecraft, a range-finding problem is solved. A known method of solving includes the following operations:

The transmission by each of the NCAs with which interaction is established of high-precision forecast data of its location and the specified grouping almanac.

Calculation of the software location based on the solution of the system of n range-finding equations:

,

,

where l = 1, 2 ... n-1; n≥3.

Secondary processing of navigation information and assessment of the accuracy of navigation software definitions can be performed based on traditional methods. Possible solutions to this system of rangefinder equations in finite and iterative procedures. To analyze the accuracy of the location, error estimates of position surfaces (lines) are used, which are found directly from the errors of range-finding measurements through the gradients of the navigation field. The volume (area) of uncertainty in the location of the software is minimal when the NAC of the working constellation is located in orthogonal directions (in this case, with equal-accurate range measurements, the geometric factor K for positioning on the horizontal plane is minimal

Quasi-autonomous rangefinding satellite positioning can be carried out using existing ground-based quantum optical systems. In this case, retroreflectors 14 are used.

For operational guidance on ground-based laser beacons in system 5, a wide-angle laser direction finder 19 is introduced.

Direction finder 15 is used to accurately determine the directions to ground beacons and exit points of the response radiation of the software from under the water.

When using “nanosecond” laser pulses of the “green” wavelength range, the errors of range-finding single laser measurements between deeply immersed software and mid-orbit spacecraft are units of meters (and can be brought to tens of centimeters, for example, when working from depths of several tens of meters through standard atmosphere and ocean water).

A system that implements the proposed method can ensure the achievement of the following tactical and technical characteristics of information and coordinate support:

The orbit of the spacecraft (GLONASS system) is 19100 km.

Software immersion depth for a navigation-connected session is from 0 to 200 m.

The accuracy of software location is up to ten meters.

Information transfer rate - up to 1 kbit / s.

Communication efficiency in multichannel communication through continuous cloud cover (i.e., transmission of messages to a given region of the ocean by all satellites of the working constellation) - from 5 to 10 s.

Power consumption of satellite equipment:

during a communication session - from 350 to 380 W,

between communication sessions - about 50 watts,

including:

laser coordinate information support system (LSIKO):

in a session - from 300 to 330 W,

between sessions - from 10 to 20 watts,

inter-satellite laser measuring and communications system (MLISS) - up to 50 watts.

The mass of satellite laser equipment - 80 kg,

including:

LSIKO - from 40 to 50 kg,

MLISS - from 18 to 20 kg,

astrosystems - up to 8 kg.

The technical and economic advantage of the proposed technical solution is to increase the operational efficiency of underwater vehicles, which is achieved by:

- increase the technical stability of information support based on the high reliability of bilateral laser channels between a submerged underwater vehicle and satellites, as well as between satellites and a mobile command post;

- increasing the autonomy of the ephemeris-time support of satellites based on inter-satellite laser measurements;

- increasing the efficiency of delivery of control commands to a submerged underwater vehicle by a constellation of satellites and reliable transmission of information from the underwater vehicle to its control point;

- improving the accuracy and efficiency of the coordinate support of submerged underwater objects.

Claims (1)

The method of coordinate information support of underwater objects, which consists in transmitting laser navigation and communication signals from the spacecraft, characterized in that the laser navigation and communication signals transmit into the ocean in the form of request signals from the board of three or more spacecraft, which are satellites detect and decode the transmitted signals on the underwater object, determine the numbers of the satellites and identify them by decoded signals, measure the pseudorange between the underwater object the object and the corresponding satellites, determine the coordinates of the underwater object and the correction for the ship’s time scale relative to the system time of the space navigation system taking into account the measured pseudoranges, in addition, the angular position of the glare generated by the transmission of the transmitted request laser signals of the satellites through the excited surface of the water is recorded on the underwater object, select the brightest of them, emit response laser signals in the direction of the selected glare, record the time between the moment of receiving the last request signal and the moment of emission of the first response signal, on the satellites of the orbital constellation, based on cloud analysis, they emit signals through the gaps in the clouds, measure the time interval between the moment of emission of the last request signals and the first response signal, transmit the measurement results, entering them into frame of the navigation signal, in the direction of arrival of the response signal, receive and decode this signal on the underwater object and determine the true range between taking into account the measured signal delays, the depth of immersion of the underwater object and the direction of radiation of the response signal of the underwater object, determine the time correction of the ship’s time scale of the underwater object relative to the satellite clock based on a comparison of the pseudo- and true ranges, the satellites are emitted tied to their onboard the time scale pulsed laser signals in the directions of several satellites in its orbital plane and in the direction of several satellites in neighboring orbital planes, measure the inter-satellite ranges and shifts of the airborne time scales on the basis of the sum-difference relationships of time intervals between the moments of emission of natural pulses and the reception of pulsed laser signals from neighboring satellites, tied to the corresponding time points relative to the airborne scales, determine the corrections of the radial components of the ephemeris based on the inter-satellite ranges, these corrections are introduced into the frames of the interrogation signals emitted in the direction of the served area of the World kean, the decoded information extracted from the response signals of the underwater object, put in the format of the inter-satellite laser signal and transmitted through a chain of satellites in a given area, which is a ground, surface, underwater or air control center for the actions of underwater objects.

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