CN113050092B - AIS signal-based atmospheric waveguide detection system - Google Patents
AIS signal-based atmospheric waveguide detection system Download PDFInfo
- Publication number
- CN113050092B CN113050092B CN202110251834.XA CN202110251834A CN113050092B CN 113050092 B CN113050092 B CN 113050092B CN 202110251834 A CN202110251834 A CN 202110251834A CN 113050092 B CN113050092 B CN 113050092B
- Authority
- CN
- China
- Prior art keywords
- ais
- signal receiver
- ais signal
- atmospheric waveguide
- shipborne
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 119
- 238000004891 communication Methods 0.000 claims abstract description 106
- 238000012544 monitoring process Methods 0.000 claims description 32
- 238000000034 method Methods 0.000 claims description 17
- 230000006978 adaptation Effects 0.000 claims description 2
- 238000012545 processing Methods 0.000 claims description 2
- 238000002372 labelling Methods 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 10
- 230000008859 change Effects 0.000 description 9
- 230000005540 biological transmission Effects 0.000 description 7
- 238000011160 research Methods 0.000 description 7
- 230000006855 networking Effects 0.000 description 6
- 238000005259 measurement Methods 0.000 description 4
- 230000001965 increasing effect Effects 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 238000007726 management method Methods 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 238000005562 fading Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000013307 optical fiber Substances 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 238000011897 real-time detection Methods 0.000 description 1
- 230000001932 seasonal effect Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/95—Radar or analogous systems specially adapted for specific applications for meteorological use
- G01S13/956—Radar or analogous systems specially adapted for specific applications for meteorological use mounted on ship or other platform
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
Landscapes
- Engineering & Computer Science (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Physics & Mathematics (AREA)
- Ocean & Marine Engineering (AREA)
- Electromagnetism (AREA)
- Computer Networks & Wireless Communication (AREA)
- General Physics & Mathematics (AREA)
- Traffic Control Systems (AREA)
- Position Fixing By Use Of Radio Waves (AREA)
Abstract
The invention discloses an atmospheric waveguide detection system based on an AI S signal. The detection system comprises a shipborne AI S device and an AI S signal receiver, wherein the distance between the shipborne AI S device and the AI S signal receiver is larger than the wireless line-of-sight distance of the AI S signal transmitted by the shipborne AI S device, and when the AI S signal receiver scans and receives the AI S signal transmitted by the shipborne AI S device, an atmospheric waveguide exists between the position of the shipborne AI S device and the receiving position of the AI S signal receiver. The system further comprises a wireless communication receiving and transmitting device which is integrally arranged, instant communication is carried out based on the detected atmospheric wave guide, and the detected atmospheric wave guide is marked and forecasted through a display system. The detection system has strong detection practicability on the atmospheric wave guide, low cost and high application value.
Description
Technical Field
The invention relates to the technical field of communication, in particular to an atmosphere waveguide detection system based on AIS signals.
Background
Typically, atmospheric waveguides have horizontal dimensions of kilometers to hundreds of kilometers and vertical dimensions of meters to hundreds of meters. Atmospheric waveguides often occur in marine atmospheric environments because of their relatively good horizontal uniformity and the ease with which weather conditions can be created.
However, the atmospheric waveguide has a dynamic change characteristic, and the dynamic change is represented by a dynamic change of a position and a distance, and also represented by a dynamic change of intensity of the atmospheric waveguide for transmitting a radio signal, so that the atmospheric waveguide must be detected and forecasted for radio communication, so that the atmospheric waveguide is effectively utilized for radio communication.
In the prior art, the method for detecting the atmospheric waveguide generally obtains atmospheric parameters such as temperature, humidity, direction and the like by means of sounding equipment such as a sounding rocket or a balloon, calculates and obtains the refractive indexes of the atmospheres with different heights, obtains the vertical section of the refractive indexes, further judges the existence condition of the atmospheric waveguide, and provides data support for beyond-the-horizon transmission. The method is mainly used for scientific research on the atmospheric waveguide, the obtained atmospheric waveguide data are mainly used for atmospheric waveguide observation and prediction, direct correlation between atmospheric waveguide detection and atmospheric waveguide application cannot be formed, theoretical research on the atmospheric waveguide is mainly performed instead of application research, real-time detection results of the atmospheric waveguide are difficult to directly apply to the atmospheric waveguide communication application, and the method is also limited by various aspects such as detection equipment, detection space and conditions, manpower and material resource cost and the like, only scientific research on a limited range and limited conditions can be performed, and the practical industrial application value is not high.
Disclosure of Invention
The invention mainly solves the technical problems of complex and expensive atmospheric waveguide detection method, weak real-time performance of atmospheric waveguide detection, difficulty in instant communication by utilizing the atmospheric waveguide and the like in the prior art.
In order to solve the technical problems, the technical scheme adopted by the invention is to provide an atmosphere waveguide detection system based on AIS signals, wherein the detection system comprises shipborne AIS equipment and an AIS signal receiver, the distance between the shipborne AIS equipment and the AIS signal receiver is larger than the wireless line-of-sight distance of AIS signals transmitted by the shipborne AIS equipment, and when the AIS signal receiver scans and receives AIS signals transmitted by the shipborne AIS equipment, atmosphere waveguides exist between the position of the shipborne AIS equipment and the receiving position of the AIS signal receiver.
Preferably, the AIS signal receiver synchronously detects and scans the AIS signals emitted by a plurality of shipborne AIS devices, the shipborne AIS devices are distributed at different positions and are located outside the maximum boundary of wireless line-of-sight communication, and after the AIS signal receiver receives the AIS signals emitted by at least one shipborne AIS device, the AIS signals emitted by the corresponding shipborne AIS devices are indicated to be transmitted over-the-horizon through the atmospheric waveguide, and the atmospheric waveguide exists between the position of the shipborne AIS devices and the receiving position of the AIS signal receiver.
Preferably, the detection system further comprises a wireless communication transceiver device integrally arranged with the shipborne AIS device, and a wireless communication transceiver device integrally arranged with the AIS signal receiver, when an atmospheric waveguide exists between the position of the shipborne AIS device and the receiving position of the AIS signal receiver, wireless communication is established through the wireless communication transceiver device, and the signal frequency of the wireless communication is the same as or similar to the frequency of the AIS signal transmitted by the shipborne AIS device.
Preferably, the detection system further comprises a positioning module integrally arranged with the shipborne AIS equipment, the positioning module is used for positioning the position of the shipborne AIS equipment, and after wireless communication is established between the position of the shipborne AIS equipment and the AIS signal receiver through the wireless communication transceiver, positioning information output by the positioning module is sent to the AIS signal receiver, so that the AIS signal receiver can obtain the position of the shipborne AIS equipment.
Preferably, the detection system further comprises a monitoring module integrally arranged with the shipborne AIS equipment, the monitoring module is used for monitoring the region where the shipborne AIS equipment is located, and after wireless communication is established between the position where the shipborne AIS equipment is located and the AIS signal receiver through the wireless communication transceiver, monitoring information output by the monitoring module is sent to the AIS signal receiver, so that the AIS signal receiver can obtain the monitoring information of the region where the shipborne AIS equipment is located.
Preferably, the AIS signal receiver also has a positioning module, which is used for positioning the position of the AIS signal receiver, and the AIS signal receiver sends the position information of the AIS signal receiver and the received position information of the shipborne AIS equipment to the local display control system, so that the geographical information can be marked and displayed.
Preferably, the positioning module further acquires time information, so that dynamic changes of the atmospheric waveguide along with time are detected and displayed on the local display control system.
Preferably, the AIS signal receiver further comprises a second communication module, and the second communication module is further in communication interconnection with the remote display control system, so that the detection and display of the atmospheric waveguide information from the AIS signal receivers are realized.
Preferably, the AIS signal receiver further comprises a second communication module, and the second communication module is in communication interconnection with other AIS signal receivers, so that communication interconnection among a plurality of shipboard AIS devices is realized.
The beneficial effects of the invention are as follows: the invention discloses an atmosphere waveguide detection system based on AIS signals. The detection system comprises shipborne AIS equipment and an AIS signal receiver, wherein the distance between the shipborne AIS equipment and the AIS signal receiver is larger than the wireless line-of-sight distance of AIS signals transmitted by the shipborne AIS equipment, and when the AIS signal receiver scans and receives the AIS signals transmitted by the shipborne AIS equipment, an atmospheric waveguide exists between the position of the shipborne AIS equipment and the receiving position of the AIS signal receiver. The system further comprises a wireless communication receiving and transmitting device which is integrally arranged, instant communication is carried out based on the detected atmospheric wave guide, and the detected atmospheric wave guide is marked and forecasted through a display system. The detection system has strong detection practicability on the atmospheric wave guide, low cost and high application value.
Drawings
FIG. 1 is a global AIS marine data distribution schematic;
FIG. 2 is a schematic diagram of the point-to-point atmospheric waveguide detection extension principle according to one embodiment of a method for atmospheric waveguide detection, prediction and communication using AIS signals;
FIG. 3 is a schematic diagram of an atmospheric waveguide detection principle according to an embodiment of a method for atmospheric waveguide detection, prediction and communication using AIS signals;
FIG. 4 is a schematic diagram of the shore-based atmospheric waveguide detection principle in another embodiment of a method for atmospheric waveguide detection, prediction and communication using AIS signals;
FIG. 5 is a schematic diagram of the principle of open sea and offshore atmospheric waveguide detection in accordance with another embodiment of the method of atmospheric waveguide detection, prediction and communication using AIS signals;
FIG. 6 is a block diagram of an embodiment of an atmospheric waveguide detection system based on AIS signals;
FIG. 7 is a block diagram of another embodiment of an atmospheric waveguide detection system according to an AIS signal;
FIG. 8 is a block diagram of another embodiment of an atmospheric waveguide detection system according to an AIS signal;
FIG. 9 is a block diagram of another embodiment of an atmospheric waveguide detection system according to an AIS signal;
fig. 10 is a block diagram of another embodiment of an atmospheric waveguide detection system based on AIS signals.
Detailed Description
In order that the invention may be readily understood, a more particular description thereof will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used in this specification includes any and all combinations of one or more of the associated listed items.
The AIS system (Automatic Identification System) is a short name of an automatic ship identification system, and is a navigation aid system applied to marine safety and communication between ships and between banks. The ship-borne AIS equipment consists of a VHF communication machine, a GPS positioning instrument and a communication controller connected with a ship-borne display. The VHF is abbreviated as Very High Frequency herein, i.e., very high frequency, and means that the frequency band is from 30MHz to 300MHz. The ship-borne AIS equipment is matched with a GPS to broadcast ship dynamic information such as ship position, ship speed, course rate change and course, and the like, and combines ship static information such as ship name, calling sign, draft and dangerous goods to the ships and the lands in the nearby water area by the very high frequency VHF, so that the nearby ships and the lands can timely master the navigation consultation of all the ships on the nearby sea surface, and take necessary avoidance actions, thereby effectively guaranteeing the navigation safety of the ships.
Preferably, in order to realize safety monitoring of the marine navigation ship, the AIS data is transmitted based on the satellite communication equipment, so that global AIS ship data can be constructed, and the navigation position of the marine ship can be marked and displayed in real time, namely, an electronic chart is constructed. The marine navigation ship anti-collision system is not only used for anti-collision installation protection between adjacent ships, but also used for monitoring and management of marine navigation ships.
As shown in fig. 1, which shows a global AIS ship data distribution diagram showing the sailing distribution of ships A1 distributed throughout the world ocean, it can be seen that these ships have a very high sailing distribution density, particularly sailing ships with a high density distribution on a given course. The type of the ship, the ship name, the ship number, the expected arrival time of the ship, the ship departure time, the ship berthing port information, the ship position (longitude and latitude), the maximum draft of the ship, the ship sailing speed, the transit area and other information can be obtained through AIS ship data, and the comprehensive functions of the data are to identify and track the ship, avoid the ship collision as much as possible, and strengthen maritime management and the like.
Further, normally, sailing vessels are information-interactive by transmitting and receiving very high frequency VHF signals from each other over a range of apparent distances. However, in practical application, because of the existence of the atmospheric waveguide above the ocean, VHF signals sent by the VHF communication machine of the shipboard AIS device can be transmitted over the atmospheric waveguide, so that the VHF signals can be scanned and received by the receiver within the range of the over-the-horizon distance, and the atmospheric waveguide can be detected.
Preferably, as shown in fig. 3, the on-board AIS equipment installed on the offshore navigation vessel C1 transmits an AIS signal, where the AIS signal may include radio signals in a plurality of different frequency bands, for example, the aforementioned radio signals in the VHF frequency band, an AIS signal receiver J1 is disposed outside the maximum boundary of the line-of-sight wireless communication of the AIS signal, and when the AIS signal receiver J1 scans and receives the AIS signal, location information of the vessel transmitting the signal may be obtained from the signal, which indicates that the AIS signal is transmitted over the line-of-sight through the atmospheric waveguide, and at the same time, the atmospheric waveguide exists between the location of the on-board AIS equipment (i.e., the location of the vessel C1) and the receiving location of the AIS signal receiver.
Further, the maximum boundary of line-of-sight wireless communication herein refers to:
here, H 1 and H 2 refer to the heights of the antennas at the two transmitting and receiving ends, for example, the heights of the antennas at the two ends are all 10 meters, and if the antenna works in the VHF band, R max ≡95km can be calculated. AIS signal receiver J1 is therefore considered to receive AIS signals from vessels outside of 95km, and is considered to have been over-the-horizon transmitted through the atmospheric waveguide.
It follows that when an AIS signal of one vessel is received by the other vessel in this way, the propagation distance of the AIS signal can be determined from the distance between the locations of the two vessels, and if the distance is greater than the maximum boundary of line-of-sight wireless communication, this indicates that the AIS signal is over-line-of-sight transmitted through the atmospheric waveguide, and also indicates that there is an atmospheric waveguide between the locations of the two vessels.
Preferably, we can use this method to conduct atmospheric waveguide detection by two vessels with on-board AIS equipment, for example, at regular intervals, for example, every 5 minutes, or every 5 seconds, within 24 hours of a day, so as to study the real-time and interval variations of atmospheric waveguides, and to study the use of atmospheric waveguides for over-the-horizon communications. Further, the method is used for long-term atmospheric waveguide detection in a selected sea area, a selected position, a selected route, a selected meteorological condition and a selected seasonal time, and the detection result is recorded to establish a forecast of the atmospheric waveguide.
Preferably, application detection for communication by using the atmospheric waveguide can be increased, and the application includes detection of communication basic conditions such as communication bandwidth, rate, error rate, signal fading, modulation mode and the like. Preferably, although the on-board AIS device is operated in the VHF band, on the basis of using the on-board AIS device to realize over-the-horizon wireless communication of signals in the VHF band by using atmospheric waveguides, atmospheric waveguide communication detection can be performed on other bands adjacent to the VHF band, for example, ultra high frequency Ultra High Frequency (UHF) refers to atmospheric waveguide communication detection with a frequency of 300-3000 MHz. Therefore, the corresponding wide-frequency-band atmospheric waveguide communication detection device can be developed, the working frequency can be selected in the VHF frequency band for detection, the frequency band can be expanded for detection, and the detection method is based on the detection that the atmospheric waveguide beyond-view-distance communication can be carried out by the ship-borne AIS device in the VHF frequency band, and then the atmospheric waveguide beyond-view-distance communication detection is carried out on other frequency bands.
Further, when an atmospheric waveguide is detected between the point-to-point, a nearby area may also be selected for point-to-face detection. As shown in fig. 2, after the existence of the atmospheric waveguide between the first proximal position A1 and the first distal position B1 is detected by the method, the atmospheric waveguide detection can be continuously performed along the transverse direction for the third proximal position A3 and the third distal position B3, and the expanding distance can be gradually expanded in a gradually increasing manner, and of course, the atmospheric waveguide detection can also be performed for the third proximal position A3 and the first distal position B1, and the atmospheric waveguide detection can be performed for the first proximal position A1 and the third distal position B3; further, the distance may be further extended along the longitudinal direction, for example, the atmospheric waveguide detection may be performed between the second proximal position A2 and the first distal position B2, the atmospheric waveguide detection may be performed between the second proximal position A2 and the fourth distal position B4, and the atmospheric waveguide detection may be performed between the fourth proximal position A4 and the first distal position B1, the second distal position B2, and the fourth distal position B4, respectively, and the extended distance may be gradually extended in a gradually increasing manner. Through the expansion distance, an area surrounded by the first near-end position A1 to the fourth near-end position A4 and an atmosphere waveguide detection area surrounded by the first far-end position B1 to the fourth far-end position B4 can be further formed, the detection range of the atmosphere waveguide is expanded, the expansion distance can be gradually expanded in a small gradually-increasing mode, the area range where the atmosphere waveguide exists can be accurately found, accurate area detection is achieved, and the accident of point-to-point detection is converted into the area range determined by the face detection.
The above is a point-to-point atmospheric waveguide detection method, based on fig. 3, further performs point-to-multipoint atmospheric waveguide detection, where the AIS signal receiver J1 performs detection scanning on AIS signals emitted by a plurality of shipborne AIS devices (such as C1, C2, and C3 in fig. 1) distributed at different positions and all located outside the maximum boundary of line-of-sight wireless communication, and after receiving the AIS signal emitted by at least one shipborne AIS device, indicates that the AIS signal emitted by the corresponding shipborne AIS device performs over-the-horizon transmission through the atmospheric waveguide, and detects that an atmospheric waveguide exists between the location of the shipborne AIS device and the receiving location of the AIS signal receiver J1.
The method can detect the atmospheric wave guide by utilizing the AIS signal of the ship, does not need to additionally detect by various special detection devices, and greatly saves the detection cost. Furthermore, the method can detect the existence of the atmospheric waveguide, which lays a foundation for further researching the characteristics of the atmospheric waveguide, so that the method can further research and detect the generation rule and the composition characteristics of the atmospheric waveguide after detecting the atmospheric waveguide. Preferably, the method can detect the atmospheric constitution above the region where the atmospheric waveguide exists, and comprises the steps of detecting the characteristics of humidity, vapor distribution, cloud layer distribution and the like of the atmospheric bottom layer by using an unmanned aerial vehicle and detecting the meteorological conditions of the height, density, thickness and the like of the cloud layer above the region where the atmospheric waveguide exists by using meteorological satellites. Therefore, the research on the atmospheric waveguide is more definite in directivity, the existing atmospheric waveguide characteristics are detected and analyzed on the basis of the atmospheric waveguide existence condition obtained by the method with high efficiency and low cost, and the research efficiency is greatly improved due to the fact that the target object is definite.
Preferably, based on fig. 3, the AIS signal receivers are arranged along the coast base to scan and receive the AIS signals sent by a plurality of ships, when the AIS signals are received, the position of the ship can be clearly judged by further using the AIS ship data shown in fig. 1, so that the position relationship and the distance between the ship and the coast base AIS signal receivers can be more accurately determined, and when the distance is obviously beyond the range of the sight line transmission of the AIS signals, the AIS signals are indicated to be transmitted in a communication way through the atmospheric waveguide.
Of course, the arrangement mode of the shore-based detection can be transferred to an island, and the AIS signal receivers are arranged on the island, so that AIS signals sent by a plurality of ships can be scanned and received within a range of one circumference. And this radius of circumference is chosen to be greater than the maximum boundary of line-of-sight wireless communication. Therefore, preferably, the AIS signal receivers are distributed on the islands in a concentric circle mode, concentric circles with different radiuses are set, and then the AIS signals are scanned and received on the ships on the concentric circles with different radiuses, so that the detection study of the atmospheric waveguides can be realized. Further, a plurality of islands or vessels parked by parking may be selected as the circle centers of the circle detection, and the distance between the circle centers is equal to or greater than the maximum boundary of the line-of-sight wireless communication. Therefore, detection areas similar to a honeycomb structure can be formed, each circumferential area corresponds to one honeycomb detection area, seamless coverage of a selected sea area is achieved, detection networks of the circumferential areas can be interconnected, AIS signal receivers are distributed on islands to conduct network interconnection through satellite communication, summarization and sharing of detection results are achieved, and effective detection coverage of atmospheric wave guide is achieved in a larger range.
Through the modes, the atmospheric waveguide can be measured without special atmospheric waveguide detection equipment, the cost of atmospheric waveguide measurement is greatly reduced, the real-time performance, the dynamic performance, the tracking performance and the verification performance of the measurement are very high, the measured atmospheric waveguide can be directly utilized for communication, and the atmospheric waveguide measurement device is wider in region range.
Further, because the marine course of vessels is relatively fixed and the vessels carrying AIS equipment are numerous, although the vessels are dynamic, measurements of the atmospheric waveguides from one sea location to the shore can be made on different vessels traveling to that point, that is, on different vessels on the same course, including on different vessels traveling through the same location, and also on the same vessel or vessels traveling through different locations, and by measuring, facilitating atmospheric waveguide predictions for the selected course, directly serving the vessels traveling on the course. Therefore, long-term atmospheric waveguide monitoring of a certain position on a route can be realized, atmospheric waveguide can be predicted by combining with weather, hydrology and other change conditions, and future atmospheric waveguide conditions can be predicted in advance.
Preferably, the AIS signal receiver scans the ship of the ship-borne AIS equipment which receives the AIS signal, and the corresponding position is obtained through AIS ship data or chart inquiry and positioning, so that the detected atmospheric waveguide coverage area is marked on a map; and measuring the intensity of the AIS signals received by each AIS signal receiver distributed on the shore in real time, thereby recording the detected corresponding waveguide change condition, forming a dynamic recording database of the fundamental wave guide of the shore, and being used for forecasting the waveguide distribution and intensity of the coastal area.
Further preferably, as shown in fig. 4, the AIS signal receivers have a plurality of (e.g., J1, J2, J3) shore-based arrangements along the coast line spacing, and each of the AIS signal receivers detects and scans the AIS signals transmitted by the on-board AIS devices located outside the maximum boundary of the wireless line-of-sight communications within a sector area detection range, and when the AIS signal receiver scans and receives the AIS signals, it indicates that the AIS signals have been transmitted over the line-of-sight through the atmospheric waveguide, and at the same time, an atmospheric waveguide exists between the location of the on-board AIS devices and the receiving location of the AIS signal receiver.
Preferably, the position setting between two adjacent AIS signal receivers in fig. 4 is determined according to the size of a fan-shaped included angle (such as α1, α2, α3), where the size of the fan-shaped included angle is required to satisfy that the distance (such as Q1 in the figure) between the intersection point of two adjacent fan-shaped boundaries and the AIS signal receiver is exactly the maximum boundary of the AIS signal wireless line-of-sight communication, so that the continuity of coverage can be ensured. When the distance between two adjacent AIS signal receivers increases, the fan-shaped included angle also increases, so that the area range of scanning and receiving of a single AIS signal receiver increases, and in practical application, the single AIS signal receiver is difficult to receive and process AIS signals sent by different ships too much, so that the fan-shaped included angle and the distance between the adjacent AIS signal receivers are reasonably arranged, namely, the position and the number of the shore-based AIS signal receivers are reasonably distributed, and the monitoring of the processing capacity of receiving AIS signals and the adaptation of the monitoring range are facilitated.
Further, fig. 5 also shows that the AIS signal receivers (such as D1, D2, D3) are further arranged on offshore islands or on offshore annular by special measuring vessels, and each AIS signal receiver is arranged in a detection range of a sector area, and performs detection scanning on AIS signals transmitted by on-board AIS equipment located outside the maximum boundary of wireless line-of-sight communication in the detection range, when the AIS signal receiver scans and receives the AIS signals, the AIS signal is indicated to perform over-the-horizon transmission through an atmospheric waveguide, and at the same time, an atmospheric waveguide exists between the location of the on-board AIS equipment and the receiving location of the AIS signal receiver.
By arranging the AIS signal receivers D1, D2 and D3 on the offshore, the problem that the detection range of the shore-based AIS signal receivers J1, J2 and J3 is limited in the depth direction is facilitated to be expanded, the detection capability of an open sea atmosphere waveguide is further enhanced, and the expansion of the atmosphere waveguide detection from coastal to offshore and open sea is facilitated.
Preferably, the AIS signal receivers D1, D2, D3 arranged offshore scan the ship of the on-board AIS device that receives the AIS signal, and obtain the corresponding position by inquiring and locating the AIS ship data or sea chart, so as to mark the detected atmospheric waveguide coverage area on the map; and measuring the intensity of the AIS signals received by each AIS signal receiver arranged offshore, recording the detected corresponding waveguide change condition, forming an offshore waveguide dynamic recording database, and predicting the waveguide distribution and intensity of an offshore area.
Preferably, the position of the offshore AIS signal receivers D1, D2 and D3 may be selected by laying the offshore AIS signal receivers according to the atmospheric waveguide detected by the shore AIS signal receivers in fig. 5, that is, the AIS signal receivers D1, D2 and D3 are laid at the offshore position with the atmospheric waveguide stably existing, so that over-the-horizon communication between the offshore AIS signal receivers D1, D2 and D3 and the shore AIS signal receivers J1, J2 and J3 through the atmospheric waveguide may be realized, and thus, not only the detection of the atmospheric waveguide may be realized, but also the communication may be performed by using the detected atmospheric waveguide, so that relay communication may be performed at the position of the offshore AIS signal receivers, and multiple-place networking for monitoring the atmospheric waveguide may be realized, and meanwhile, the networking detection and networking communication costs may be greatly reduced.
Preferably, the AIS signal receivers D1, D2, D3 may be deployed offshore to form a plurality of annular multi-layer progressive deployments (e.g., annular deployments L1, L2, L3), thereby allowing complementation of the detection range between adjacent layers and also further enhancing the detection range to open sea.
Further, as shown in fig. 5, the AIS signal receivers are further arranged in a punctiform manner (such as M1, M2 and M3) on the offshore islands, each AIS signal receiver detects and scans the AIS signals emitted by the on-board AIS devices located outside the maximum boundary of the wireless line-of-sight communication in a circular area detection range, and when the AIS signal receiver scans and receives the AIS signals, the AIS signal receiver indicates that the AIS signals are transmitted over the line-of-sight through the atmospheric waveguide, and at the same time, the atmospheric waveguide exists between the location of the on-board AIS devices and the receiving location of the AIS signal receiver.
Preferably, the AIS signal receivers (such as M1, M2, M3) are arranged at the detection positions selected by the offshore islands, and the AIS signal receivers M1, M2, M3 are also arranged at the offshore positions with stable existence of the atmospheric waveguide detected by the shore-based AIS signal receivers or/and the offshore AIS signal receivers, so that the overscan communication between the offshore AIS signal receivers M1, M2, M3 and the offshore AIS signal receivers D1, D2, D3 or/and the shore-based AIS signal receivers J1, J2, J3 through the atmospheric waveguide can be realized, the detection of the atmospheric waveguide can be realized, the communication can be realized by utilizing the detected atmospheric waveguide, the relay communication can be realized at the position of the offshore AIS signal receivers, the multi-place networking of the atmospheric waveguide monitoring is realized, and the networking detection and networking communication cost is greatly reduced.
Preferably, the AIS signal receivers M1, M2, M3 arranged in open sea scan the ship at the location of the on-board AIS device that receives the AIS signal, and obtain the corresponding location by querying and locating the AIS ship data or sea chart, so as to mark the detected atmospheric waveguide coverage area on a map; and measuring the intensity of the AIS signals received by each AIS signal receiver distributed in the open sea point in real time, thereby recording the detected corresponding waveguide change condition, forming an open sea waveguide dynamic recording database, and being used for forecasting the waveguide distribution and intensity in the open sea area.
Preferably, based on the shore-based, offshore and offshore deployed AIS signal receivers shown in fig. 3-5, after the atmospheric waveguides are detected, communication links are established between the corresponding coasts and/or islands using the atmospheric waveguides, thereby enabling over-the-horizon communication between offshore and offshore.
Preferably, based on the shore-based, offshore and open sea AIS signal receivers shown in fig. 3 to 5, after the atmospheric waveguides are detected, monitoring links are established between the corresponding coasts and/or islands by using the atmospheric waveguides, so that natural conditions such as hydrology, weather and the like of a specific region can be monitored, and the monitoring information can be transmitted in real time through communication links constructed by the atmospheric waveguides to form a monitoring link.
Based on the same conception, the invention also provides an atmosphere waveguide detection system based on the AIS signal. Preferably, as shown in fig. 6, the detection system includes a shipborne AIS device and an AIS signal receiver, where a distance between the shipborne AIS device and the AIS signal receiver is greater than a wireless line of sight distance of an AIS signal transmitted by the shipborne AIS device, and when the AIS signal receiver scans and receives the AIS signal transmitted by the shipborne AIS device, an atmospheric waveguide exists between a location of the shipborne AIS device and a receiving location of the AIS signal receiver.
Preferably, as shown in fig. 7, the AIS signal receiver may synchronously perform detection scanning on AIS signals transmitted by a plurality of shipborne AIS devices, where the plurality of shipborne AIS devices are distributed at different positions and are located outside the maximum boundaries of wireless line-of-sight communications, and after the AIS signal receiver receives the AIS signal transmitted by at least one shipborne AIS device, it indicates that the AIS signal transmitted by the corresponding shipborne AIS device performs over-the-horizon transmission through an atmospheric waveguide, and at the same time, an atmospheric waveguide exists between the position of the shipborne AIS device and the receiving position of the AIS signal receiver.
Further preferably, as shown in fig. 8, the detection system further includes a wireless communication transceiver device integrally provided with the on-board AIS device, and a wireless communication transceiver device integrally provided with the AIS signal receiver, and when it is detected that an atmospheric waveguide exists between the location of the on-board AIS device and the receiving location of the AIS signal receiver, wireless communication is established through the wireless communication transceiver device, and the signal frequency of the wireless communication is the same as or similar to the frequency of the AIS signal transmitted by the on-board AIS device.
Preferably, on the basis of the embodiment shown in fig. 8, as shown in fig. 9, the detection system further includes a positioning module integrally provided with the on-board AIS device, where the positioning module is configured to position the on-board AIS device, and after wireless communication is established between the position of the on-board AIS device and the AIS signal receiver through the wireless communication transceiver, positioning information output by the positioning module is sent to the AIS signal receiver, so that the AIS signal receiver can obtain the position of the on-board AIS device. Preferably, the positioning module is a positioning module carried by the on-board AIS equipment itself. The positioning module can comprise a plurality of positioning modes such as satellite positioning, inertial navigation positioning and the like.
Preferably, the detection system further comprises a monitoring module integrally arranged with the shipborne AIS equipment, and the monitoring module is used for monitoring the region where the shipborne AIS equipment is located, wherein the monitoring mainly refers to various monitoring technical means such as video, audio, infrared and electromagnetic. After wireless communication is established between the position of the shipborne AIS equipment and an AIS signal receiver through the wireless communication transceiver, monitoring information output by the monitoring module is sent to the AIS signal receiver, and therefore the AIS signal receiver can obtain monitoring information of the region where the shipborne AIS equipment is located.
Furthermore, the AIS signal receiver is also provided with a positioning module, so that the position of the AIS signal receiver can be positioned, the AIS signal receiver sends the position information of the AIS signal receiver and the received position information of the shipborne AIS equipment to a local display control system, so that geographic information marking and displaying can be performed, and the situation that an atmospheric waveguide exists between the AIS signal receiver and the shipborne AIS equipment on a map or a sea chart can be displayed. Preferably, the positioning module also acquires time information, so that dynamic changes of the atmospheric waveguide along with time can be detected and displayed on the local display control system.
Preferably, on the basis of the embodiment of fig. 9, as shown in fig. 10, the AIS signal receiver further has a second communication module, where the second communication module may be a plurality of types of communication modules, for example, a satellite communication module, an optical fiber communication module, a computer network communication module, etc., and further may implement transmission of more information over a longer distance and/or more information amounts through the second communication module, and transmit the information to the remote display control system, so that it may implement receiving and displaying information sent by a plurality of AIS signal receivers deployed at different positions, and form more comprehensive real-time dynamic display information of an atmospheric waveguide, which is beneficial for the AIS signal receiver to be deployed on shore, off-shore, or on-shore, so that not only can implement detection of the atmospheric waveguide, but also can implement long-distance and large-capacity data transmission of the obtained detection information based on the detected atmospheric waveguide through the second communication module.
Preferably, the second communication module is in communication interconnection with other AIS signal receivers, so that communication interconnection among a plurality of shipboard AIS devices is realized.
Preferably, the AIS signal receiver further comprises a task planning module, and the task planning module can generate a detection task according to the existence condition of the detected atmospheric wave guide, wherein the detection task comprises selecting a detection position, constructing a detection layout mode and the like, so that the AIS signal receiver is guided to complete various detection tasks. Reference is made to the previous description of fig. 2 to 5.
Preferably, the AIS signal receiver further comprises an information interconnection module connected with the unmanned aerial vehicle, the remote sensing satellite and the meteorological satellite, so that physical characteristic analysis of the detected atmospheric wave guide and the detection system on the atmospheric wave guide of the region is realized.
It can be seen that the invention discloses an atmosphere waveguide detection system based on AIS signals. The detection system comprises shipborne AIS equipment and an AIS signal receiver, wherein the distance between the shipborne AIS equipment and the AIS signal receiver is larger than the wireless line-of-sight distance of AIS signals transmitted by the shipborne AIS equipment, and when the AIS signal receiver scans and receives the AIS signals transmitted by the shipborne AIS equipment, an atmospheric waveguide exists between the position of the shipborne AIS equipment and the receiving position of the AIS signal receiver. The system further comprises a wireless communication receiving and transmitting device which is integrally arranged, instant communication is carried out based on the detected atmospheric wave guide, and the detected atmospheric wave guide is marked and forecasted through a display system. The detection system has strong detection practicability on the atmospheric wave guide, low cost and high application value.
The foregoing description is only illustrative of the present invention and is not intended to limit the scope of the invention, and all equivalent structural changes made by the present invention and the accompanying drawings, or direct or indirect application in other related technical fields, are included in the scope of the present invention.
Claims (8)
1. The atmospheric waveguide detection system based on the AIS signals is characterized by comprising shipborne AIS equipment and an AIS signal receiver, wherein the distance between the shipborne AIS equipment and the AIS signal receiver is larger than the wireless line-of-sight distance of the AIS signals transmitted by the shipborne AIS equipment, and when the AIS signal receiver scans and receives the AIS signals transmitted by the shipborne AIS equipment, atmospheric waveguides exist between the position of the shipborne AIS equipment and the receiving position of the AIS signal receiver; the AIS signal comprises a VHF frequency band signal and/or a UHF frequency band signal;
The detection system further comprises wireless communication receiving and transmitting equipment which is integrally arranged with the shipborne AIS equipment and wireless communication receiving and transmitting equipment which is integrally arranged with the AIS signal receiver, when the atmospheric waveguide exists between the position of the shipborne AIS equipment and the receiving position of the AIS signal receiver, wireless communication is established through the wireless communication receiving and transmitting equipment, and the signal frequency of the wireless communication is the same as or similar to the AIS signal frequency transmitted by the shipborne AIS equipment;
The method comprises the steps of realizing the adaptation of the processing capacity of monitoring and receiving AIS signals and a monitoring range by reasonably arranging the positions and the number of the AIS signal receivers on a shore basis; and setting positions between the AIS signal receivers on two adjacent shore bases, and determining according to the size of a sector included angle, wherein the size of the sector included angle meets the requirement that the distance between the intersection point of two adjacent sector boundaries and the AIS signal receiver is the maximum boundary of wireless line-of-sight communication of the AIS signal.
2. The system of claim 1, wherein the AIS signal receiver is configured to synchronously perform detection scanning on AIS signals transmitted by a plurality of on-board AIS devices, wherein the plurality of on-board AIS devices are distributed at different positions and are located outside a maximum boundary of wireless line-of-sight communication, and when the AIS signal receiver receives the AIS signal transmitted by at least one on-board AIS device, the AIS signal transmitted by the corresponding on-board AIS device indicates that the on-board AIS signal is transmitted over the line-of-sight through an atmospheric waveguide, and the atmospheric waveguide exists between the position of the on-board AIS device and the receiving position of the AIS signal receiver.
3. The atmospheric waveguide detection system based on an AIS signal according to claim 1, wherein the detection system further comprises a positioning module integrally arranged with the on-board AIS device, the positioning module is used for positioning the on-board AIS device, and after wireless communication is established between the on-board AIS device and an AIS signal receiver through the wireless communication transceiver, positioning information output by the positioning module is sent to the AIS signal receiver, so that the AIS signal receiver can obtain the on-board AIS device.
4. The atmospheric waveguide detection system based on AIS signals according to claim 3, wherein the detection system further comprises a monitoring module integrally arranged with the on-board AIS equipment, the monitoring module is used for monitoring the region where the on-board AIS equipment is located, and after wireless communication is established between the position of the on-board AIS equipment and an AIS signal receiver through the wireless communication transceiver, monitoring information output by the monitoring module is sent to the AIS signal receiver, so that the AIS signal receiver can obtain the monitoring information of the region where the on-board AIS equipment is located.
5. An AIS signal based atmospheric waveguide detection system according to claim 3 wherein the AIS signal receiver also has a locating module to locate the location of the AIS signal receiver, the AIS signal receiver transmitting its own location information, and the received location information of the on-board AIS device to a local display control system, whereby geographical information labelling and display is enabled.
6. The AIS signal based atmospheric waveguide detection system of claim 5 wherein the positioning module further obtains time information whereby dynamic changes in atmospheric waveguide over time are detected and displayed on a local display control system.
7. The AIS signal based atmospheric waveguide detection system of claim 6 wherein the AIS signal receivers further comprise a second communication module, the second communication module being further communicatively interconnected with a remote display control system to enable detection and display of atmospheric waveguide information from a plurality of AIS signal receivers.
8. The AIS signal based atmospheric waveguide detection system of claim 6 wherein said AIS signal receiver further comprises a second communication module through which it is communicatively interconnected with other said AIS signal receivers, thereby effecting communicative interconnection between a plurality of on-board AIS devices.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110251834.XA CN113050092B (en) | 2021-03-08 | 2021-03-08 | AIS signal-based atmospheric waveguide detection system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110251834.XA CN113050092B (en) | 2021-03-08 | 2021-03-08 | AIS signal-based atmospheric waveguide detection system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113050092A CN113050092A (en) | 2021-06-29 |
| CN113050092B true CN113050092B (en) | 2024-05-17 |
Family
ID=76510728
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110251834.XA Active CN113050092B (en) | 2021-03-08 | 2021-03-08 | AIS signal-based atmospheric waveguide detection system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113050092B (en) |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1725031A (en) * | 2005-06-08 | 2006-01-25 | 中国人民解放军海军大连舰艇学院 | Evaporation waveguide monitoring diagnosing evaluating method and device |
| JP2006163765A (en) * | 2004-12-07 | 2006-06-22 | Natl Inst For Land & Infrastructure Management Mlit | Ship navigation monitoring system |
| CN101013465A (en) * | 2007-02-08 | 2007-08-08 | 深圳市当代通信技术有限公司 | Multi-label anti-collision algorithm in ultrahigh frequency remote auto-recognition system |
| WO2008148188A1 (en) * | 2007-06-08 | 2008-12-11 | Com Dev International Ltd. | System and method for decoding automatic identification system signals |
| CN102305936A (en) * | 2011-05-23 | 2012-01-04 | 张淑芳 | Autonomous positioning navigation system for automatic identification system (AIS) vessel |
| CN103135108A (en) * | 2011-11-23 | 2013-06-05 | 北京雷音电子技术开发有限公司 | Method and terminal for detecting and diagnosing atmospheric duct in real time |
| US9425769B1 (en) * | 2014-07-18 | 2016-08-23 | Hrl Laboratories, Llc | Optically powered and controlled non-foster circuit |
| CN108055068A (en) * | 2017-12-08 | 2018-05-18 | 上海埃威航空电子有限公司 | A kind of airborne simulation system and test method for receiving marine ais signal |
| CN108627825A (en) * | 2018-03-29 | 2018-10-09 | 北京无线电测量研究所 | A kind of analysis method and system of radar detection probability |
| CN110162082A (en) * | 2018-04-11 | 2019-08-23 | 北京机电工程研究所 | Telemetry receiving processing system based on high altitude kite balloon object platform |
| CN209401048U (en) * | 2019-01-31 | 2019-09-17 | 四川新源现代智能科技有限公司 | A kind of Logistics Park automatic car identification system |
-
2021
- 2021-03-08 CN CN202110251834.XA patent/CN113050092B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006163765A (en) * | 2004-12-07 | 2006-06-22 | Natl Inst For Land & Infrastructure Management Mlit | Ship navigation monitoring system |
| CN1725031A (en) * | 2005-06-08 | 2006-01-25 | 中国人民解放军海军大连舰艇学院 | Evaporation waveguide monitoring diagnosing evaluating method and device |
| CN101013465A (en) * | 2007-02-08 | 2007-08-08 | 深圳市当代通信技术有限公司 | Multi-label anti-collision algorithm in ultrahigh frequency remote auto-recognition system |
| WO2008148188A1 (en) * | 2007-06-08 | 2008-12-11 | Com Dev International Ltd. | System and method for decoding automatic identification system signals |
| CN102305936A (en) * | 2011-05-23 | 2012-01-04 | 张淑芳 | Autonomous positioning navigation system for automatic identification system (AIS) vessel |
| CN103135108A (en) * | 2011-11-23 | 2013-06-05 | 北京雷音电子技术开发有限公司 | Method and terminal for detecting and diagnosing atmospheric duct in real time |
| US9425769B1 (en) * | 2014-07-18 | 2016-08-23 | Hrl Laboratories, Llc | Optically powered and controlled non-foster circuit |
| CN108055068A (en) * | 2017-12-08 | 2018-05-18 | 上海埃威航空电子有限公司 | A kind of airborne simulation system and test method for receiving marine ais signal |
| WO2019109989A1 (en) * | 2017-12-08 | 2019-06-13 | 上海埃威航空电子有限公司 | On-board simulation system for receiving marine ais signals and testing method |
| CN108627825A (en) * | 2018-03-29 | 2018-10-09 | 北京无线电测量研究所 | A kind of analysis method and system of radar detection probability |
| CN110162082A (en) * | 2018-04-11 | 2019-08-23 | 北京机电工程研究所 | Telemetry receiving processing system based on high altitude kite balloon object platform |
| CN209401048U (en) * | 2019-01-31 | 2019-09-17 | 四川新源现代智能科技有限公司 | A kind of Logistics Park automatic car identification system |
Non-Patent Citations (8)
| Title |
|---|
| 关于我国进行远距离信息探测的研究;张哲 等;海事研究;第52-55页 * |
| 基于岸基雷达探测及反演海上蒸发波导研究;关振红 等;第27届中国气象学会年会雷达技术开发与应用分会场论文集;第1-6页 * |
| 某型无人机系统级电磁兼容试验方法研究;柳锐锋 等;舰船电子工程;20151231(第9期);第165-175页 * |
| 海上VHF /UHF 频段信道环境及其空时频率选择性;王峰 等;电子学报(第6期);1523-1529 * |
| 海洋大气波导信道特性分析与应用;赵中军;康欣;曹仲晴;;无线电工程;20131105(11);第36-39页 * |
| 王鹤 等.王鹤 等.船讯网在山东沿海地区船舶管理中的应用研究.2018,(第2期),94-98. * |
| 王鹤 等;王鹤 等;船讯网在山东沿海地区船舶管理中的应用研究(第2期);94-98 * |
| 蒸发波导预测设备检验方法研究;曹鑫;雷达与对抗;第36卷(第2期);15-18 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113050092A (en) | 2021-06-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6665631B2 (en) | System and method for measuring short distances | |
| US8314730B1 (en) | Collection of meteorological data by vehicles | |
| CN111951610B (en) | Ship-bridge collision avoidance active anti-collision intelligent early warning system and method | |
| EP1735638B1 (en) | Method and system for determining the position of marine vessels and similar objects | |
| US20210039756A1 (en) | Floating platform for maritime surveillance | |
| RU2371738C1 (en) | Hydroacoustic navigation system | |
| CN104391281A (en) | Method for improving sky-wave radar sea surface ship target tracking and positioning precision | |
| CN103503232A (en) | Method and system for maritime high speed broadband communication networking | |
| KR101131944B1 (en) | Vessel traffic system | |
| WO2008114955A1 (en) | Electronic vessel guide method and system for harbor and narrow channel | |
| CN113050196B (en) | Method for detecting, forecasting and communicating atmospheric waveguide by AIS signal | |
| CN112213707A (en) | Method for predicting action range of ship-borne pulse radar in evaporation waveguide environment | |
| EP2329291B1 (en) | Sensors in concert for maritime surveillance | |
| CN113050092B (en) | AIS signal-based atmospheric waveguide detection system | |
| CN106530836A (en) | VTS (Virtual Terminal Service) system based on distributed radars | |
| Stateczny et al. | FMCW radar implementation in River Information Services in Poland | |
| KR101304910B1 (en) | Method and system for network creation for ship monitoring | |
| Vesecky et al. | Using HF surface wave radar and the ship Automatic Identification System (AIS) to monitor coastal vessels | |
| CN115792917A (en) | Over-the-horizon ground wave radar-based marine emergency search and rescue meteorological early warning method | |
| CN102628932A (en) | Multifunctional navigation radar based on Beidou satellite | |
| CN110780324B (en) | Electronic ship board based on real-time connection of Internet of things | |
| Gewies et al. | Availability of maritime radio beacon signals for R-mode in the southern baltic sea | |
| KR20120026679A (en) | Aids to lighthouse, radio-navigation service system | |
| RU108154U1 (en) | SHIP OPERATION SAFETY SYSTEM | |
| Raz et al. | Exploiting information fusion for cybersecurity of small unmanned aerial vehicles |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |