A cross-ice sound communication system and method

Abstract

The object of the present invention is to provide a cross-ice acoustic communication system and method, including an ice surface communication device and an underwater communication device. Based on the propagation characteristics of floating ice sound, the present invention uses ice layer acoustic propagation channels and underwater acoustic propagation channels at the same time, and transmits information from the ice surface to the water by exciting longitudinal waves between plates in the ice, thereby solving the problem that downlink long-distance communication cannot be achieved due to the rapid attenuation of direct waves in the water excited by ice surface seismic sources, and realizes the effective transmission and reception of acoustic signals across the ice medium, thereby completing acoustic communication across the ice medium. Uplink communication and downlink communication use different frequency bands for communication, that is, the ice surface communication device can simultaneously transmit signals through the ice layer acoustic propagation channel and receive signals through the underwater acoustic propagation channel, thereby realizing full-duplex communication and improving communication efficiency. At the same time, the three-component data analysis and processing received on the ice surface and the directional reception of the underwater receiving module can effectively reduce the interference of the transmitted signal and noise, and improve the quality of the received signal.

Description

Technical Field

[0001] The present invention relates to a polar communication system and method, in particular to a cross-ice acoustic communication system and method. Background Art

[0002] The Arctic region is known as the world's only "white ocean" because it is covered by sea ice all year round. Sea ice, as a regulator of global climate, is also the biggest obstacle to the development and utilization of polar resources. The core challenges of establishing three-dimensional polar information acquisition and transmission capabilities are precisely the problems of blocked cross-ice medium information transmission links caused by the existence of sea ice and limited polar ocean information acquisition.

[0003] The communication method usually uses electromagnetic waves as carriers, which are affected by the absorption of ice and water and are not applicable in the Arctic ice and water environment; the acoustic wave communication method commonly used in the marine environment is more used for underwater acoustic communication under the ice surface. For cross-ice communication, it is usually necessary to drill through the ice surface and lay cables through relay equipment such as ice-based buoys, and transmit through cables to the surface of the ice layer on the basis of underwater communication. This method requires breaking ice to lay cables, which greatly increases the cost burden, construction risks and application environment limitations. In addition, cross-ice communication is more about using seismic detectors to collect direct wave signals in the water under the ice, and thus complete the uplink communication from the water to the ice surface in the cross-ice medium communication. Due to the energy conversion problem of signal transmission across the medium, the communication channel from ice to water cannot be simply regarded as the reversal of the communication channel from water to ice. The diffusion of the sub-ice surface acoustic wave excited by the ice surface source attenuates rapidly and the propagation distance is limited. The above-mentioned uplink communication path cannot realize the downlink communication from the ice surface to the water. Therefore, the traditional underwater acoustic transceiver communication equipment based on channel reversal is not suitable for two-way communication across the ice medium. However, existing cross-ice medium transmission is limited to transmitting signals from the water under the ice to the ice surface, and there is no research on downlink communication from the ice surface to the water under the ice. Summary of the invention

[0004] The object of the present invention is to provide a cross-ice acoustic communication system and method that can meet the needs of polar cross-ice communication interaction.

[0005] The object of the present invention is achieved in that:

[0006] The invention discloses an inter-ice acoustic communication system, which is characterized in that it comprises an ice surface communication device, the ice surface communication device comprises an ice surface shell, an ice surface signal processing module, an ice surface acquisition module, an ice surface transmitting module, an ice surface power supply module, and a satellite communication module, the ice surface signal processing module, the ice surface acquisition module, the ice surface transmitting module, the ice surface power supply module, and the satellite communication module are installed in the ice surface shell, the ice surface signal processing module is respectively connected with the ice surface acquisition module, the ice surface transmitting module, the ice surface satellite communication module, and the ice surface power supply module; the ice surface acquisition module comprises a three-component detector composed of three mutually orthogonal accelerometers, which collects external vibration information and transmits the acquired information to the ice surface signal processing module; the ice surface signal processing module analyzes and decodes the collected information, and simultaneously sends communication signals to the ice surface transmitting module and the satellite communication module; the ice surface transmitting module comprises a circumferentially vibrating cylindrical oscillator, which transmits the communication signal in the form of circumferential vibration after receiving the communication signal from the ice surface signal processing module; the satellite communication module exchanges information with other ice acoustic communication systems or communication satellites in the form of electromagnetic waves after receiving the communication signal from the ice surface signal processing module.

[0007] A cross-ice acoustic communication system of the present invention may also include:

[0008] 1. Also includes an underwater communication device, the underwater communication device includes: an underwater shell, an underwater signal processing module, an underwater acquisition module, an underwater transmitting module, and an underwater power module. The underwater signal processing module, the underwater acquisition module, the underwater transmitting module, and the underwater power module are installed in the underwater shell. The underwater signal processing module is respectively connected to the underwater acquisition module, the underwater transmitting module, and the underwater power module. The underwater acquisition module includes a directional hydrophone to collect underwater sound pressure information and transmit the acquired information to the underwater signal processing module; the underwater signal processing module analyzes and decodes the collected information and sends a communication signal to the underwater transmitting module at the same time; the underwater transmitting module includes an omnidirectional underwater acoustic transmitting transducer, which transmits the communication signal of the underwater signal processing module in the form of sound waves.

[0009] 2. An insulation layer is set in the ice surface shell to insulate the ice surface acquisition module, ice surface signal processing module, ice surface power supply module and satellite communication module to prevent the modules from suspending work or being damaged due to low temperature. The ice surface signal processing module controls and optimizes the entire system, including power supply time control of the ice surface transmission module and satellite communication module.

[0010] 3. The underwater shell is provided with a waterproof layer to provide waterproof protection for the underwater acquisition module, underwater transmission module, underwater signal processing module and underwater power module to prevent the module from suspending work or being damaged due to water ingress.

[0011] The present invention provides a method for cross-ice acoustic communication, which is characterized by: comprising a downlink communication method for ice layer excitation and water reception:

[0012] (1) Arranging the ice surface communication device on the ice surface, wherein the ice surface transmitting module and the ice surface collecting module are buried in the ice layer, coupled and fixed, and then starting the ice surface power supply module;

[0013] (2) Transmitting signal: The ice surface signal processing module uses frequency band W 1 Modulation Coded Communication InformationX 1 Get the transmission signal Sig 1 , and transmits the signal Sig 1 The ice surface transmitting module uses a cylindrical vibrator with circumferential vibration to excite the signal Sig 1 , the circumferential vibration excites the longitudinal waves between the ice plates to propagate in the ice layer. When the sound waves propagate in the ice layer, the energy will continue to leak into the water and propagate in the water in a specific direction θ, where θ is the angle between the propagation direction and the normal to the ice surface;

[0014] (3) Received signal: Transmitted signal Sig propagated through the ice layer 1 , propagates in the water at a fixed angle θ, and is received by the hydrophone of the underwater acquisition module with a receiving directivity facing the ice surface and a beam opening angle of θ; where the angle θ is related to the longitudinal wave velocity c between the plates in the ice. p 、wave speed in water c w Related, θ is obtained by Snell's law;

[0015] (4) Signal analysis and processing: The signal Sig received by the underwater acquisition module 1 The signal is transmitted to the underwater signal processing module, and after decoding and analysis, the communication signal X is obtained. 1 , completing the downlink communication received in the water by the ice layer.

[0016] A cross-ice sound communication method of the present invention may also include:

[0017] 1. Also includes an uplink communication method of exciting in water and receiving on ice surface:

[0018] a. Transmitting signal: The underwater signal processing module uses frequency band W 2 Modulation Coded Communication InformationX 2 Get the transmission signal Sig 2 , and transmits the signal Sig 2 The signal is transmitted to the underwater transmitting module, which uses an omnidirectional underwater acoustic transducer to transmit the signal Sig 2 , the sound waves will propagate omnidirectionally in the water;

[0019] b. Received signal: underwater sound wave signal Sig 2 It propagates to the lower surface of the ice layer and is collected by the three-component accelerometer of the ice surface collection module through the vibration of the ice layer;

[0020] c. Signal analysis and processing: The ice surface acquisition module receives the signal Sig 2 The signal is transmitted to the ice surface signal processing module, which obtains the communication signal X after noise reduction and decoding analysis of the three-component information. 2 , completing the uplink communication of excitation in water and reception on ice surface;

[0021] d. Transmit signals to satellites or other communication devices through antennas to achieve networking communication functions.

[0022] The advantages of the present invention are:

[0023] (1) Acoustic communication across the ice layer: Based on the propagation characteristics of floating ice sound, the acoustic propagation channel across the ice layer (inter-plate longitudinal waves) and the acoustic propagation channel across the water (direct waves in the water) are used simultaneously. By exciting inter-plate longitudinal waves in the ice, information is transmitted from the ice surface to the water. This solves the problem of being unable to achieve downlink long-distance communication due to the rapid attenuation of direct waves in the water excited by the ice surface earthquake source. The effective transmission and reception of acoustic signals across the ice medium is achieved, thus completing acoustic communication across the ice medium.

[0024] (2) Achieve full-duplex communication and improve communication efficiency: Uplink communication (water-ice surface) and downlink communication (ice surface-water) use different frequency bands, that is, the ice surface communication device can simultaneously transmit signals of the ice layer acoustic propagation channel and receive signals of the underwater acoustic propagation channel, achieving full-duplex communication and improving communication efficiency. At the same time, the three-component data analysis and processing of ice surface reception and the directional reception of the underwater receiving module can effectively reduce the interference of the transmission signal and noise, improve the quality of the received signal, and ensure the effective duplex communication.

[0025] (3) Increased practicality: The underwater communication device of the present invention is conventional and universal and can be installed on an under-ice submersible. The ice surface communication device is simple to deploy and operate. It only needs to be fixed vertically on the ice surface to achieve communication with the water under the ice. At the same time, it can communicate with the satellite through the satellite communication module to achieve ultra-long-distance cross-medium communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the ice surface communication device;

[0027] Figure 2 This is a schematic diagram of an underwater communication device;

[0028] Figure 3 is a flow chart of the method of the present invention;

[0029] Figure 4 It is a communication schematic diagram of the present invention. DETAILED DESCRIPTION

[0030] The present invention is described in more detail below with reference to the accompanying drawings:

[0031] Combination Figure 1-4 The present invention discloses an ice surface communication device of a cross-ice sound communication system, comprising: a housing 1, a receiving module 2, a transmitting module 3, a signal processing module 4, a power module 5, and a satellite communication module 6. The housing 1 is provided with a receiving module 2, a transmitting module 3, a signal processing module 4, a power module 5, and a satellite communication module 6; the signal processing module 4 is electrically connected to the receiving module 2, the transmitting module 3, and the satellite communication module 6 respectively, and the power module 5 supplies power to the other modules; the receiving module 2 is composed of a three-component detector composed of three mutually orthogonal accelerometers, which is used to collect external vibration information and transmit the acquired information to the signal processing module 4; the signal processing module 4 is used to analyze and decode the collected information, and send communication signals to the transmitting module 3 and the satellite communication module 6 at the same time; the transmitting module 3 is composed of a circumferentially vibrating cylindrical vibrator, which is used to transmit the communication signal of the signal processing module 4 in the form of circumferential vibration after receiving the communication signal of the signal processing module 4; the satellite communication module 6 is used to exchange information with other ice sound communication systems or communication satellites in the form of electromagnetic waves after receiving the communication signal of the signal processing module 4.

[0032] The housing 1 is also provided with an insulation layer to insulate the receiving module 2, the signal processing module 4, the power module 5 and the satellite communication module 6 to prevent the modules from suspending operation or being damaged due to low temperature. The signal processing module 4 is not only used for decoding and analyzing the received signal and determining the transmitted signal, but also for controlling and optimizing the entire system, such as controlling the power supply time of the transmitting module 3 and the satellite communication module 6.

[0033] Figure 2 The schematic diagram of the underwater communication device includes: a housing 7, a receiving module 8, a transmitting module 9, a signal processing module 10 and a power module 11. The housing 7 is provided with a waterproof layer to provide waterproof protection for the receiving module 8, the transmitting module 9, the signal processing module 10 and the power module 11 to prevent the modules from suspending operation or being damaged due to water ingress; the signal processing module 10 is electrically connected to the receiving module 8 and the transmitting module 9 respectively, and the power module 11 supplies power to the other modules; the receiving module 8 is composed of a directional hydrophone, which is used to collect sound pressure information in the water and transmit the acquired information to the signal processing module 10; the signal processing module 10 is used to analyze and decode the collected information and send a communication signal to the transmitting module 9 at the same time; the transmitting module 9 is composed of an omnidirectional underwater acoustic emission transducer, which is used to transmit the communication signal of the signal processing module 10 in the form of sound waves after receiving it.

[0034] Figure 3 The present invention provides a communication step across the ice sound communication system:

[0035] According to the inter-plate longitudinal wave velocity c in the cross-ice medium communication area p 、wave speed in water cw , θ is obtained by the following formula, and the directivity of the underwater receiving module 8 is set based on it (the receiving directivity faces the ice surface, and the opening angle is θ).

[0036]

[0037] (1) Downlink communication method with ice layer excitation and water reception:

[0038] 1) The ice surface communication device is arranged on the ice surface, the transmitting module 3 and the receiving module 2 are buried in the ice layer, and after coupling and fixing, the power supply module 5 is started;

[0039] 2) Transmitting signal: Ice surface signal processing module 4 transmits signal in frequency band W 1 Modulation Coded Communication InformationX 1 Get the transmission signal Sig 1 , and transmits the signal Sig 1 The ice surface transmitting module 3 uses a cylindrical vibrator with circumferential vibration to excite the signal Sig 1 Circumferential vibration is used to excite longitudinal waves between ice sheets to propagate in the ice. When sound waves propagate in the ice, energy will continue to leak into the water and propagate in the water in a specific direction θ (θ is the angle between the propagation direction and the normal to the ice surface);

[0040] 3) Signal reception: The transmitted signal Sig propagates through the ice layer 1 , will leak into the water at a fixed angle θ and be received by the hydrophone of the underwater receiving module 8 whose receiving directivity is facing the ice surface and whose opening angle is θ;

[0041] The angle θ is related to the longitudinal wave velocity c between the plates in the ice. p 、wave speed in water c w Related, θ can be obtained by Snell's law;

[0042] 4) Signal analysis and processing: The signal Sig received by the underwater receiving module 8 1 The signal is transmitted to the underwater signal processing module 10, and after decoding and analysis, the communication signal X is obtained. 1 , completing the downlink communication received in the water by the ice layer.

[0043] (2) Uplink communication method with excitation in water and reception on ice surface:

[0044] 1) Transmitting signal: The underwater signal processing module 10 transmits a signal in the frequency band W 2 Modulation Coded Communication InformationX 2 Get the transmission signal Sig 2 , and transmits the signal Sig 2 The underwater transmitting module 9 transmits the signal Sig using an omnidirectional underwater acoustic transducer. 2, the sound waves will propagate omnidirectionally in the water;

[0045] 2) Signal reception: underwater sound wave signal Sig 2 It propagates to the lower surface of the ice layer and is collected by the three-component accelerometer of the ice surface receiving module 2 through the vibration of the ice layer.

[0046] 3) Signal analysis and processing: The signal Sig received by the ice surface receiving module 2 2 The signal is transmitted to the ice surface signal processing module 4, and after noise reduction and decoding analysis of the three-component information, the communication signal X is obtained. 2 , completing the uplink communication of excitation in water and reception on the ice surface.

[0047] 4) Satellite communication module 6, which transmits signals to satellites or other communication devices through antennas to realize networking communication functions.

Claims

1. A method for cross-ice acoustic communication, characterized by: Downlink communication method including ice layer excitation and water reception: (1) Arranging the ice surface communication device on the ice surface, wherein the ice surface transmitting module and the ice surface collecting module are buried in the ice layer, coupled and fixed, and then starting the ice surface power supply module; (2) Transmitting signal: The ice surface signal processing module modulates the encoded communication information X1 with the frequency band W1 to obtain the transmitting signal Sig1, and transmits the transmitting signal Sig1 to the ice surface transmitting module. The ice surface transmitting module uses a circumferentially vibrating cylindrical oscillator to excite the signal Sig1. The circumferential vibration excites the longitudinal waves between the ice plates to propagate in the ice layer. When the sound waves propagate in the ice layer, the energy will continue to leak into the water and propagate in the water in a specific direction θ, where θ is the angle between the propagation direction and the normal to the ice surface; (3) Received signal: The transmitted signal Sig1 propagates through the ice layer and propagates in the water at a fixed angle θ. It is received by the underwater acquisition module hydrophone with a receiving directivity facing the ice surface and a beam opening angle of θ. The angle θ is related to the velocity of the longitudinal wave between the plates in the ice, c p 、wave speed in water c w Related, θ is obtained by Snell's law; (4) Signal analysis and processing: The signal Sig1 received by the underwater acquisition module is transmitted to the underwater signal processing module. After decoding and analysis, the communication signal X1 is obtained, completing the downlink communication of the ice layer stimulating the underwater reception.

2. The method for cross-ice acoustic communication according to claim 1, characterized in that: The ice surface communication device includes an ice surface shell, an ice surface signal processing module, an ice surface acquisition module, an ice surface transmitting module, an ice surface power module, and a satellite communication module. The ice surface signal processing module, the ice surface acquisition module, the ice surface transmitting module, the ice surface power module, and the satellite communication module are installed in the ice surface shell. The ice surface signal processing module is respectively connected to the ice surface acquisition module, the ice surface transmitting module, the ice surface satellite communication module, and the ice surface power module; the ice surface acquisition module includes a three-component detector composed of three mutually orthogonal accelerometers, which collects external vibration information and transmits the acquired information to the ice surface signal processing module; the ice surface signal processing module analyzes and decodes the collected information, and simultaneously sends communication signals to the ice surface transmitting module and the satellite communication module; the ice surface transmitting module includes a circumferentially vibrating cylindrical oscillator, which transmits the communication signal in the form of circumferential vibration after receiving the communication signal from the ice surface signal processing module; the satellite communication module exchanges information with other ice acoustic communication systems or communication satellites in the form of electromagnetic waves after receiving the communication signal from the ice surface signal processing module.

3. The method for cross-ice acoustic communication according to claim 2, characterized in that: An insulation layer is provided in the ice surface shell to insulate the ice surface acquisition module, ice surface signal processing module, ice surface power supply module and satellite communication module to prevent the modules from suspending work or being damaged due to low temperature. The ice surface signal processing module controls and optimizes the entire system, including power supply time control of the ice surface transmission module and the satellite communication module.

4. The method for cross-ice acoustic communication according to claim 1, characterized in that: It also includes an uplink communication method that is stimulated in water and received on the ice surface: a. Transmitting signal: The underwater signal processing module modulates the encoded communication information X2 with the frequency band W2 to obtain the transmitting signal Sig2, and transmits the transmitting signal Sig2 to the underwater transmitting module. The underwater transmitting module uses an omnidirectional underwater acoustic transducer to transmit the signal Sig2, and the sound wave will propagate omnidirectionally in the water; b. Received signal: The underwater acoustic wave signal Sig2 propagates to the lower surface of the ice layer and is collected by the three-component accelerometer of the ice surface acquisition module through the vibration of the ice layer; c. Signal analysis and processing: The ice surface acquisition module transmits the received signal Sig2 to the ice surface signal processing module. The ice surface signal processing module obtains the communication signal X2 through noise reduction and decoding analysis of the three-component information, completing the uplink communication of water excitation and ice surface reception; d. Transmit signals to satellites or other communication devices through antennas to achieve networking communication functions.

5. The method for cross-ice acoustic communication according to claim 4, characterized in that: The underwater communication device includes: an underwater shell, an underwater signal processing module, an underwater acquisition module, an underwater transmitting module, and an underwater power supply module. The underwater signal processing module, the underwater acquisition module, the underwater transmitting module, and the underwater power supply module are installed in the underwater shell. The underwater signal processing module is connected to the underwater acquisition module, the underwater transmitting module, and the underwater power supply module respectively. The underwater acquisition module includes a directional hydrophone to collect underwater sound pressure information and transmit the acquired information to the underwater signal processing module; the underwater signal processing module analyzes and decodes the collected information and sends a communication signal to the underwater transmitting module at the same time; the underwater transmitting module includes an omnidirectional underwater acoustic transmitting transducer, which transmits the communication signal from the underwater signal processing module in the form of sound waves.

6. The method for cross-ice acoustic communication according to claim 5, characterized in that: The underwater shell is provided with a waterproof layer to provide waterproof protection for the underwater acquisition module, the underwater transmission module, the underwater signal processing module and the underwater power supply module, so as to prevent the modules from suspending operation or being damaged due to water ingress.

Images